Document and Entity Information	6 Months Ended
Document and Entity Information	Jun. 30, 2013	Jul. 22, 2013
Document Documentand Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2
Trading Symbol	CINF
Entity Registrant Name	CINCINNATI FINANCIAL CORP
Entity Central Index Key	0000020286
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		163,668,282

Condensed Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Investments
Fixed maturities, at fair value (amortized cost: 2013—$8,428; 2012—$8,222)	$ 8,992	$ 9,093
Equity securities, at fair value (cost: 2013—$2,452; 2012—$2,369)	3,875	3,373
Other invested assets	66	68
Total investments	12,933	12,534
Cash and cash equivalents	382	487
Investment income receivable	116	115
Finance receivable	79	75
Premiums receivable	1,350	1,214
Reinsurance recoverable	582	615
Prepaid reinsurance premiums	26	26
Deferred policy acquisition costs	546	470
Land, building and equipment, net, for company use (accumulated depreciation: 2013—$405; 2012—$397)	213	217
Other assets	94	61
Separate accounts	713	734
Total assets	17,034	16,548
Insurance reserves
Loss and loss expense reserves	4,284	4,230
Life policy and investment contract reserves	2,345	2,295
Unearned premiums	1,947	1,792
Other liabilities	597	660
Deferred income tax	512	453
Note payable	104	104
Long-term debt and capital lease obligations	833	827
Separate accounts	713	734
Total liabilities	11,335	11,095
Commitments and contingent liabilities (Note 12)	0	0
SHAREHOLDERS' EQUITY
Common stock, par value—$2 per share; (authorized: 2013 and 2012—500 million shares; issued and outstanding: 2013—198 million shares and 2012—197 million shares)	396	394
Paid-in capital	1,162	1,134
Retained earnings	4,152	4,021
Accumulated other comprehensive income	1,221	1,129
Treasury stock at cost (2013 and 2012—34 million shares)	(1,232)	(1,225)
Total shareholders' equity	5,699	5,453
Total liabilities and shareholders' equity	$ 17,034	$ 16,548

Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Fixed maturities, amortized cost	$ 8,428	$ 8,222
Equity securities, cost	2,452	2,369
Land, building and equipment, accumulated depreciation	$ 405	$ 397
Common stock, par value	$ 2	$ 2
Common stock, authorized	500	500
Common stock, issued	198	197
Common stock, outstanding	198	197
Treasury stock, shares	34	34

Condensed Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
REVENUES
Earned premiums	$ 954	$ 877	$ 1,885	$ 1,716
Investment income, net of expenses	131	132	259	263
Total realized investment gains, net	14	6	55	19
Fee revenues	3	2	4	3
Other revenues	2	3	4	5
Total revenues	1,104	1,020	2,207	2,006
BENEFITS AND EXPENSES
Insurance losses and policyholder benefits	631	687	1,199	1,269
Underwriting, acquisition and insurance expenses	307	287	607	561
Interest expense	14	13	27	27
Other operating expenses	4	4	9	8
Total benefits and expenses	956	991	1,842	1,865
INCOME BEFORE INCOME TAXES	148	29	365	141
PROVISION (BENEFIT) FOR INCOME TAXES
Current	37	6	91	26
Deferred	1	(9)	10	(3)
Total provision (benefit) for income taxes	38	(3)	101	23
NET INCOME	$ 110	$ 32	$ 264	$ 118
PER COMMON SHARE
Net income-basic (in USD per share)	$ 0.67	$ 0.20	$ 1.62	$ 0.73
Net income-diluted (in USD per share)	$ 0.66	$ 0.20	$ 1.60	$ 0.72

Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
NET INCOME	$ 110	$ 32	$ 264	$ 118
Unrealized gains (losses) on investments available-for-sale, net of tax of ($85), ($19), $39 and $61, respectively	(159)	(34)	73	114
Amortization of pension actuarial loss and prior service cost, net of tax of $1, $0, $2 and $1, respectively	2	1	3	2
Change in life deferred acquisition costs, life policy reserves and other, net of tax of $8, $(1), $8 and $(3), respectively	16	(4)	16	(7)
Other comprehensive income (loss), net of tax	(141)	(37)	92	109
COMPREHENSIVE INCOME (LOSS)	$ (31)	$ (5)	$ 356	$ 227

- Definition

Condensed Consolidated Statements of Comprehensive Operations (USD $) In Millions, except Per Share data, unless otherwise specified 3 Months Ended 9 Months Ended Sep. 30, 2012 Sep. 30, 2011 Sep. 30, 2012 Sep. 30, 2011 REVENUES Earned premiums $ 889 $ 812 $ 2,605 $ 2,367 Investment income, net of expenses 132 130 395 393 Total realized investment gains (losses), net 10 (2) 29 77 Fee revenues 1 1 4 3 Other revenues 3 3 8 8 Total revenues 1,035 944 3,041 2,848 BENEFITS AND EXPENSES Insurance losses and policyholder benefits 571 656 1,840 2,032 Underwriting, acquisition and insurance expenses 296 260 857 775 Interest expense 14 13 41 40 Other operating expenses 2 4 10 14 Total benefits and expenses 883 933 2,748 2,861 INCOME (LOSS) BEFORE INCOME TAXES 152 11 293 (13) PROVISION (BENEFIT) FOR INCOME TAXES Current 34 17 60 (9) Deferred 7 (25) 4 (34) Provision (benefit) for income taxes 41 (8) 64 (43) NET INCOMEX - DefinitionThe portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 19 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.22) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Other Comprehensive Income -URI http://asc.fasb.org/extlink&oid=6519514 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.18) -URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 10, 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 20 -Article 9 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Net Income -URI http://asc.fasb.org/extlink&oid=6518256 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28, 29, 30 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 12: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.19) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 13: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e565-108580 Reference 14: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A7 -Appendix A Reference 15: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 16: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph d -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + DetailsName: us-gaap_NetIncomeLoss Namespace Prefix: us-gaap_ Data Type: xbrli:monetaryItemType Balance Type: credit Period Type: duration 111 19 229 30 PER COMMON SHARE Net income-basic $ 0.69 $ 0.12 $ 1.41 $ 0.19 Net income-diluted $ 0.68 $ 0.12 $ 1.40 $ 0.19 NET INCOME 111 19 229 30 OTHER COMPREHENSIVE INCOME (LOSS), BEFORE TAXX - DetailsName: us-gaap_OtherComprehensiveIncomeLossBeforeTaxPeriodIncreaseDecreaseAbstract Namespace Prefix: us-gaap_ Data Type: xbrli:stringItemType Balance Type: na Period Type: duration Unrealized gains (losses) on investments available-for-saleX - DefinitionBefore tax and reclassification adjustments amount of unrealized holding gain (loss) and transfers on available-for-sale securities. + ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 17 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 13 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 24 -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e637-108580 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=20435746&loc=SL7669646-108580 - DetailsName: us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax Namespace Prefix: us-gaap_ Data Type: xbrli:monetaryItemType Balance Type: credit Period Type: duration 263 (305) 457 (21) Reclassification adjustment for (gains) losses included in net incomeX - DefinitionBefore tax amount of the income statement impact of the reclassification adjustment for unrealized gain (loss) realized upon the sale of available-for-sale securities. + ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Reclassification Adjustments -URI http://asc.fasb.org/extlink&oid=6522872 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27357-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 24 -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e637-108580 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 18, 19 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e716-108580 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e689-108580 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e709-108580 - DetailsName: us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentForSaleOfSecuritiesIncludedInNetIncomeBeforeTax Namespace Prefix: us-gaap_ Data Type: xbrli:monetaryItemType Balance Type: credit Period Type: duration (10) 2 (29) (77) Unrealized (losses) on otherX - DefinitionOther Comprehensive Income, Other, Before Tax + ReferencesNo definition available. - DetailsName: cinf_OtherComprehensiveIncomeOtherBeforeTax Namespace Prefix: cinf_ Data Type: xbrli:monetaryItemType Balance Type: credit Period Type: duration (6) (6) (16) (7) Unrealized gains (losses) on investments available-for-sale and otherX - DefinitionOther Comprehensive Income (Loss), Available-for-sale Securities Adjustment and Other, before Tax + ReferencesNo definition available. - DetailsName: cinf_OtherComprehensiveIncomeLossAvailableforsaleSecuritiesAdjustmentAndOtherBeforeTax Namespace Prefix: cinf_ Data Type: xbrli:monetaryItemType Balance Type: na Period Type: duration 247 (309) 412 (105) Amortization of pension actuarial loss and prior service costX - Definition Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Actuarial Loss and Prior Service Cost Arising During Period, Before Tax.

+ References+ Details

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	$ (85)	$ (19)	$ 39	$ 61
Other Comprehensive Income Loss, Pension And Other Postretirement Benefit Plans, Net Actuarial Loss And Prior Service Cost Arising During Period, Tax	1	0	2	1
Other Comprehensive Income, Change in Life Deferred Acquisition Costs, Life Policy Reserves and Other, Tax	$ 8	$ (1)	$ 8	$ (3)

Condensed Consolidated Statements of Shareholders' Equity (USD $) In Millions	Total	Common Stock	Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock
Balance at Dec. 31, 2010
Cumulative effect of a change in accounting for deferred policy acquisition costs, net of tax	$ (22)			$ (22)
Balance (As Adjusted)	5,033	393	1,096	3,863	901	(1,220)
Balance at Dec. 31, 2011	5,055	393	1,096	3,885	901	(1,220)
Balance (in shares) (As Adjusted)		162
Balance (in shares) at Dec. 31, 2011		162
NET INCOME	118			118
Other comprehensive income, net	109				109
Dividends declared	(130)			(130)
Stock-based awards exercised and vested (in shares)		0
Stock-based awards exercised and vested	2		1			1
Stock-based compensation	8		8
Purchases	0					0
Other	4		1			3
Balance at Jun. 30, 2012	5,144	393	1,106	3,851	1,010	(1,216)
Balance (in shares) at Jun. 30, 2012		162
Balance at Dec. 31, 2012	5,453	394	1,134	4,021	1,129	(1,225)
Balance (in shares) at Dec. 31, 2012	197	163
NET INCOME	264			264
Other comprehensive income, net	92				92
Dividends declared	(133)			(133)
Stock-based awards exercised and vested (in shares)		1
Stock-based awards exercised and vested	24	2	17			5
Stock-based compensation	10		10
Purchases	(15)					(15)
Other	4		1			3
Balance (As Adjusted)	5,699
Balance at Jun. 30, 2013	$ 5,699	$ 396	$ 1,162	$ 4,152	$ 1,221	$ (1,232)
Balance (in shares) at Jun. 30, 2013	198	164

Condensed Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME	$ 264	$ 118
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	20	22
Realized gains on investments, net	(55)	(19)
Stock-based compensation	10	8
Interest credited to contract holders	22	18
Deferred income tax expense (benefit)	10	(3)
Changes in:
Investment income receivable	(1)	1
Premiums and reinsurance receivable	(103)	(76)
Deferred policy acquisition costs	(39)	(26)
Other assets	(10)	(11)
Loss and loss expense reserves	54	57
Life policy reserves	33	33
Unearned premiums	155	129
Other liabilities	(39)	7
Current income tax receivable	(70)	7
Net cash provided by operating activities	251	265
CASH FLOWS FROM INVESTING ACTIVITIES
Sale of fixed maturities	14	28
Call or maturity of fixed maturities	459	360
Sale of equity securities	157	124
Purchase of fixed maturities	(666)	(603)
Purchase of equity securities	(190)	(210)
Investment in buildings and equipment, net	(3)	(4)
Investment in finance receivables	(18)	(18)
Collection of finance receivables	14	16
Change in other invested assets, net	3	3
Net cash used in investing activities	(230)	(304)
CASH FLOWS FROM FINANCING ACTIVITIES
Payment of cash dividends to shareholders	(130)	(128)
Proceeds from stock options exercised	12	3
Contract holders' funds deposited	45	56
Contract holders' funds withdrawn	(55)	(62)
Excess tax benefits on stock-based compensation	9	1
Other	(7)	(6)
Net cash used in financing activities	(126)	(136)
Net change in cash and cash equivalents	(105)	(175)
Cash and cash equivalents at beginning of year	487	438
Cash and cash equivalents at end of period	382	263
Supplemental disclosures of cash flow information:
Interest paid	27	27
Income taxes paid	158	19
Non-cash activities:
Conversion of securities	54	13
Equipment acquired under capital lease obligations	17	9
Cashless exercise of stock options	$ 15	$ 0

Accounting Policies	6 Months Ended
Accounting Policies	Jun. 30, 2013
Accounting Policies [Abstract]
Accounting Policies	ACCOUNTING POLICIES The condensed consolidated financial statements include the accounts of Cincinnati Financial Corporation and its consolidated subsidiaries, each of which is wholly owned. These statements are presented in conformity with accounting principles generally accepted in the United States of America (GAAP). All intercompany balances and transactions have been eliminated in consolidation. The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Our actual results could differ from those estimates. Our December 31, 2012, condensed consolidated balance sheet amounts are derived from the audited financial statements but do not include all disclosures required by GAAP. Our June 30, 2013, condensed consolidated financial statements are unaudited. Certain financial information that is included in annual financial statements prepared in accordance with GAAP is not required for interim reporting and has been condensed or omitted. We believe that we have made all adjustments, consisting only of normal recurring accruals, that are necessary for fair presentation. These condensed consolidated financial statements should be read in conjunction with our consolidated financial statements included in our 2012 Annual Report on Form 10-K. The results of operations for interim periods do not necessarily indicate results to be expected for the full year. Adopted Accounting Updates ASU 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income In February 2013, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. ASU 2013-02 requires entities to present in either a single note or parenthetically on the face of the financial statements, the effect of significant amounts reclassified from each component of accumulated other comprehensive income based on its source and the income statement line items affected by the reclassification. The company adopted this ASU during the first quarter of 2013, and it did not have a material impact on our company’s financial position, cash flows or results of operations. See Note 7, Accumulated Other Comprehensive Income, for further details.

Investments

6 Months Ended

Jun. 30, 2013

Investments [Abstract]

Investments

INVESTMENTS

The following table provides cost or amortized cost, gross unrealized gains, gross unrealized losses and fair value for our invested assets:



(In millions)	Cost or
	amortized		Gross unrealized				Fair
At June 30, 2013	cost		gains		losses		value
Fixed maturities:
States, municipalities and political subdivisions	$	3,044	$	162	$	18	$	3,188
Convertibles and bonds with warrants attached	16		—		—		16
United States government	7		—		—		7
Government-sponsored enterprises	208		—		13		195
Foreign government	10		—		—		10
Commercial mortgage-backed securities	63		—		3		60
Corporate securities	5,080		459		23		5,516
Subtotal	8,428		621		57		8,992
Equity securities:
Common equities	2,375		1,398		12		3,761
Preferred equities	77		37		—		114
Subtotal	2,452		1,435		12		3,875
Total	$	10,880	$	2,056	$	69	$	12,867
At December 31, 2012
Fixed maturities:
States, municipalities and political subdivisions	$	3,040	$	250	$	1	$	3,289
Convertibles and bonds with warrants attached	31		—		—		31
United States government	7		1		—		8
Government-sponsored enterprises	164		—		—		164
Foreign government	3		—		—		3
Commercial mortgage-backed securities	27		1		—		28
Corporate securities	4,950		622		2		5,570
Subtotal	8,222		874		3		9,093
Equity securities:
Common equities	2,270		977		9		3,238
Preferred equities	99		37		1		135
Subtotal	2,369		1,014		10		3,373
Total	$	10,591	$	1,888	$	13	$	12,466

The net unrealized investment gains in our fixed-maturity portfolio are primarily the result of the current low interest rate environment that increased the fair value of our fixed-maturity portfolio. The three largest net unrealized investment gains in our common stock portfolio are from Exxon Mobil Corporation (NYSE:XOM), Chevron Corporation (NYSE:CVX) and The Procter & Gamble Company (NYSE:PG), which had a combined net gain position of $283 million. At At June 30, 2013, we had $16 million fair value of hybrid securities included in fixed maturities that follow Accounting Standards Codification (ASC) 815-15-25, Accounting for Certain Hybrid Financial Instruments, compared with $31 million fair value of hybrid securities at December 31, 2012. The hybrid securities are carried at fair value, and the changes in fair value are included in realized investment gains and losses.

The table below provides fair values and unrealized losses by investment category and by the duration of the securities’ continuous unrealized loss position:



(In millions)	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
At June 30, 2013	value		losses		value		losses		value		losses
Fixed maturities:
States, municipalities and political subdivisions	$	377	$	18	$	—	$	—	$	377	$	18
United States government	1		—		—		—		1		—
Foreign government	10		—		—		—		10		—
Government-sponsored enterprises	185		13		—		—		185		13
Commercial mortgage-backed securities	51		3		—		—		51		3
Corporate securities	580		22		13		1		593		23
Subtotal	1,204		56		13		1		1,217		57
Equity securities:
Common equities	202		12		—		—		202		12
Preferred equities	4		—		—		—		4		—
Subtotal	206		12		—		—		206		12
Total	$	1,410	$	68	$	13	$	1	$	1,423	$	69
At December 31, 2012
Fixed maturities:
States, municipalities and political subdivisions	$	53	$	1	$	—	$	—	$	53	$	1
Government-sponsored enterprises	1		—		—		—		1		—
Corporate securities	58		1		17		1		75		2
Subtotal	112		2		17		1		129		3
Equity securities:
Common equities	107		9		—		—		107		9
Preferred equities	4		1		—		—		4		1
Subtotal	111		10		—		—		111		10
Total	$	223	$	12	$	17	$	1	$	240	$	13

The following table provides investment income, realized investment gains and losses and the change in unrealized investment gains and losses and other items:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Investment income summary:
Interest on fixed maturities	$	103		$	106		$	205		$	212
Dividends on equity securities	30			27			57			53
Other investment income	—			1			1			2
Total	133			134			263			267
Less investment expenses	2			2			4			4
Total	$	131		$	132		$	259		$	263

Realized investment gains and losses summary:
Fixed maturities:
Gross realized gains	$	2		$	13		$	4		$	16
Gross realized losses	—			—			—			—
Other-than-temporary impairments	—			—			(2		)	—
Equity securities:
Gross realized gains	12			6			49			29
Gross realized losses	—			(1		)	—			(1		)
Other-than-temporary impairments	—			(14		)	—			(30		)
Securities with embedded derivatives	—			1			1			5
Other	—			1			3			—
Total	$	14		$	6		$	55		$	19

Change in unrealized gains and losses summary:
Fixed maturities	$	(282	)	$	29		$	(307	)	$	78
Equity securities	38			(82		)	419			97
Adjustment to deferred acquisition costs and life policy reserves	26			(8		)	29			(15		)
Amortization of pension actuarial loss and prior service cost	3			1			5			3
Other	(2		)	3			(5		)	5
Income taxes on above	76			20			(49		)	(59		)
Total	$	(141	)	$	(37	)	$	92		$	109

During the three and six months ended June 30, 2013 and 2012, there were no credit losses on fixed-maturity securities for which a portion of other-than-temporary impairment (OTTI) has been recognized in other comprehensive income.

During the quarter ended June 30, 2013, there were no other-than-temporarily impaired securities. At June 30, 2013, four fixed-maturity investments with a total unrealized loss of $1 million had been in an unrealized loss position for 12 months or more. Of that total, no fixed-maturity investments had fair values below 70 percent of amortized cost. There were no equity investments in an unrealized loss position for 12 months or more as of June 30, 2013.

At December 31, 2012, four fixed-maturity investments with a total unrealized loss of $1 million had been in an unrealized loss position for 12 months or more. Of that total, no fixed-maturity investments had fair values below

70 percent of amortized cost. There were no equity investments in an unrealized loss position for 12 months or more as of December 31, 2012.

Fair Value Measurements

6 Months Ended

Jun. 30, 2013

Fair Value Disclosures [Abstract]

Fair Value Measurements

FAIR VALUE MEASUREMENTS

Fair Value Hierarchy

In accordance with accounting guidance for fair value measurements and disclosures, we categorized our financial instruments, based on the priority of the observable and market-based data for the valuation technique used, into a three-level fair value hierarchy. The fair value hierarchy gives the highest priority to quoted prices with readily available independent data in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable market inputs (Level 3). When various inputs for measurement fall within different levels of the fair value hierarchy, the lowest observable input that has a significant impact on fair value measurement is used. Our valuation techniques have not changed from those used at December 31, 2012, and ultimately management determines fair value. See our 2012 Annual Report on Form 10-K, Item 8, Note 3, Fair Value Measurements, Page 121, for information on characteristics and valuation techniques used in determining fair value.

Fair Value Disclosures for Assets

The following tables illustrate the fair value hierarchy for those assets measured at fair value on a recurring basis at June 30, 2013, and December 31, 2012. We do not have any material liabilities carried at fair value. There were no transfers between Level 1 and Level 2.



(In millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At June 30, 2013			Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
Fixed maturities, available for sale:
States, municipalities and political subdivisions	$	—	$	3,187	$	1	$	3,188
Convertibles and bonds with warrants attached	—		16		—		16
United States government	7		—		—		7
Government-sponsored enterprises	—		195		—		195
Foreign government	—		10		—		10
Commercial mortgage-backed securities	—		60		—		60
Corporate securities	—		5,513		3		5,516
Subtotal	7		8,981		4		8,992
Common equities, available for sale	3,761		—		—		3,761
Preferred equities, available for sale	—		112		2		114
Taxable fixed maturities separate accounts	—		693		—		693
Top Hat Savings Plan (included in Other assets)	11		—		—		11
Total	$	3,779	$	9,786	$	6	$	13,571
At December 31, 2012
Fixed maturities, available for sale:
States, municipalities and political subdivisions	$	—	$	3,288	$	1	$	3,289
Convertibles and bonds with warrants attached	—		31		—		31
United States government	8		—		—		8
Government-sponsored enterprises	—		164		—		164
Foreign government	—		3		—		3
Commercial mortgage-backed securities	—		28		—		28
Corporate securities	—		5,567		3		5,570
Subtotal	8		9,081		4		9,093
Common equities, available for sale	3,238		—		—		3,238
Preferred equities, available for sale	—		134		1		135
Taxable fixed-maturities separate accounts	—		689		—		689
Top Hat Savings Plan (included in Other assets)	9		—		—		9
Total	$	3,255	$	9,904	$	5	$	13,164

Each financial instrument that was deemed to have significant unobservable inputs when determining valuation is identified in the following tables by security type with a summary of changes in fair value as of June 30, 2013. Total Level 3 assets continue to be less than 1 percent of financial assets measured at fair value in the condensed consolidated balance sheets. Assets presented in the table below were valued based primarily on broker/dealer quotes for which there is a lack of transparency as to inputs used to develop the valuations. The quantitative detail of these unobservable inputs is neither provided nor reasonably available to us.

The following tables provide the change in Level 3 assets for the three months ended June 30:




(In millions)	Corporate fixed maturities			States, municipalities and political subdivisions fixed maturities		Preferred equities		Total
Beginning balance, March 31, 2013	$	3		$	1	$	2	$	6
Total gains or losses (realized/unrealized):
Included in earnings	—			—		—		—
Included in other comprehensive income	—			—		—		—
Purchases	—			—		—		—
Sales	—			—		—		—
Transfers into Level 3	—			—		—		—
Transfers out of Level 3	—			—		—		—
Ending balance, June 30, 2013	$	3		$	1	$	2	$	6

Beginning balance, March 31, 2012	$	16		$	2	$	7	$	25
Total gains or losses (realized/unrealized):
Included in earnings	—			—		—		—
Included in other comprehensive income	—			—		—		—
Purchases	—			—		—		—
Sales	(1		)	—		—		(1		)
Transfers into Level 3	—			—		—		—
Transfers out of Level 3	(11		)	—		—		(11		)
Ending balance, June 30, 2012	$	4		$	2	$	7	$	13

The following tables provide the change in Level 3 assets for the six months ended June 30:




(In millions)	Corporate fixed maturities			States, municipalities and political subdivisions fixed maturities			Preferred equities		Total
Beginning balance, December 31, 2012	$	3		$	1		$	1	$	5
Total gains or losses (realized/unrealized):
Included in earnings	—			—			—		—
Included in other comprehensive income	—			—			—		—
Purchases	—			—			1		1
Sales	—			—			—		—
Transfers into Level 3	—			—			—		—
Transfers out of Level 3	—			—			—		—
Ending balance, June 30, 2013	$	3		$	1		$	2	$	6

Beginning balance, December 31, 2011	$	18		$	3		$	4	$	25
Total gains or losses (realized/unrealized):
Included in earnings	—			—			—		—
Included in other comprehensive income	3			—			2		5
Purchases	—			—			1		1
Sales	(4		)	(1		)	—		(5		)
Transfers into Level 3	1			—			—		1
Transfers out of Level 3	(14		)	—			—		(14		)
Ending balance, June 30, 2012	$	4		$	2		$	7	$	13

With the exception of the Level 3 reconciliation table, additional disclosure for the Level 3 category is not material.

Fair Value Disclosure for Assets and Liabilities Not Carried at Fair Value

The disclosures below are presented to provide timely information about the effects of current market conditions on financial instruments that are not reported at fair value in our condensed consolidated financial statements.

This table summarizes the book value and principal amounts of our long-term debt:



(In millions)				Book value				Principal amount
				June 30,		December 31,		June 30,		December 31,
Interest rate		Year of issue		2013		2012		2013		2012
6.900	%	1998	Senior debentures, due 2028	$	28	$	28	$	28	$	28
6.920	%	2005	Senior debentures, due 2028	391		391		391		391
6.125	%	2004	Senior notes, due 2034	371		371		374		374
			Total	$	790	$	790	$	793	$	793

The following table shows fair values of our note payable and long-term debt subject to fair value disclosure requirements:



(In millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At June 30, 2013			Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
Note payable	$	—	$	104	$	—	$	104
6.900% senior debentures, due 2028	—		33		—		33
6.920% senior debentures, due 2028	—		469		—		469
6.125% senior notes, due 2034	—		402		—		402
Total	$	—	$	1,008	$	—	$	1,008

At December 31, 2012
Note payable	$	—	$	104	$	—	$	104
6.900% senior debentures, due 2028	—		31		—		31
6.920% senior debentures, due 2028	—		479		—		479
6.125% senior notes, due 2034	—		431		—		431
Total	$	—	$	1,045	$	—	$	1,045

The following table shows the fair value of our life policy loans, included in other invested assets, subject to fair value disclosure requirements:



(In millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At June 30, 2013			Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
Life policy loans	$	—	$	—	$	46	$	46

At December 31, 2012
Life policy loans	$	—	$	—	$	50	$	50

Outstanding principal and interest for these life policy loans was $35 million and $37 million at June 30, 2013, and December 31, 2012, respectively.

The following table shows fair values of our deferred annuities and structured settlements, included in life policy and investment contract reserves, subject to fair value disclosure requirements:



(In millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At June 30, 2013			Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
Deferred annuities	$	—	$	—	$	887	$	887
Structured settlements	—		227		—		227
Total	$	—	$	227	$	887	$	1,114

At December 31, 2012
Deferred annuities	$	—	$	—	$	898	$	898
Structured settlements	—		240		—		240
Total	$	—	$	240	$	898	$	1,138

Recorded reserves for the deferred annuities and structured settlements were $1.049 billion and $1.043 billion at June 30, 2013, and December 31, 2012, respectively.

Property Casualty Loss and Loss Expenses

6 Months Ended

Jun. 30, 2013

Premiums Written, Net [Abstract]

Property Casualty Loss And Loss Expenses

PROPERTY CASUALTY LOSS AND LOSS EXPENSES

This table summarizes activity for our consolidated property casualty loss and loss expense reserves:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Gross loss and loss expense reserves, beginning of period	$	4,173		$	4,289		$	4,169		$	4,280
Less reinsurance receivable	349			352			356			375
Net loss and loss expense reserves, beginning of period	3,824			3,937			3,813			3,905
Net incurred loss and loss expenses related to:
Current accident year	675			725			1,209			1,380
Prior accident years	(92		)	(85		)	(102		)	(201		)
Total incurred	583			640			1,107			1,179
Net paid loss and loss expenses related to:
Current accident year	249			282			370			414
Prior accident years	272			290			664			665
Total paid	521			572			1,034			1,079
Net loss and loss expense reserves, end of period	3,886			4,005			3,886			4,005
Plus reinsurance receivable	333			332			333			332
Gross loss and loss expense reserves, end of period	$	4,219		$	4,337		$	4,219		$	4,337

We use actuarial methods, models and judgment to estimate, as of a financial statement date, the property casualty loss and loss expense reserves required to pay for and settle all outstanding insured claims, including incurred but not reported (IBNR) claims, as of that date. The actuarial estimate is subject to review and adjustment by an inter-departmental committee that includes actuarial management that is familiar with relevant company and industry business, claims and underwriting trends, as well as general economic and legal trends that could affect future loss and loss expense payments. The amount we will actually have to pay for claims can be highly uncertain. This uncertainty, together with the size of our reserves, makes the loss and loss expense reserves our most significant estimate. The reserve for loss and loss expenses in the condensed consolidated balance sheets also included $65 million at June 30, 2013, and $59 million at June 30, 2012, for certain life and health loss and loss expense reserves.

For the three months ended June 30, 2013, we experienced $92 million of favorable development on prior accident years, including $66 million of favorable development in commercial lines and $26 million of favorable development in personal lines. There was $8 million from favorable development of catastrophe losses for the three months ended June 30, 2013, compared with $5 million of favorable development of catastrophe losses that occurred for the three months ended June 30, 2012.

For the six months ended June 30, 2013, we experienced $102 million of favorable development on prior accident years, including $78 million of favorable development in commercial lines, $22 million of favorable development in personal lines and $2 million favorable development in excess and surplus lines. There was $15 million from favorable development of catastrophe losses for the six months ended June 30, 2013, compared with $27 million of favorable development of catastrophe losses that occurred for the six months ended June 30, 2012.

Life Policy and Investment Contract Reserves

6 Months Ended

Jun. 30, 2013

Liability for Future Policy Benefits [Abstract]

Life Policy And Investment Contract Reserves

LIFE POLICY AND INVESTMENT CONTRACT RESERVES

We establish the reserves for traditional life insurance policies based on expected expenses, mortality, morbidity, withdrawal rates, timing of claim presentation and investment yields, including a provision for uncertainty. Once these assumptions are established, they generally are maintained throughout the lives of the contracts. We use both our own experience and industry experience, adjusted for historical trends, in arriving at our assumptions for expected mortality, morbidity and withdrawal rates as well as for expected expenses. We base our assumptions for expected investment income on our own experience adjusted for current economic conditions.

We establish reserves for the company’s universal life, deferred annuity and structured settlement policies equal to the cumulative account balances, which include premium deposits plus credited interest less charges and withdrawals. Some of our universal life policies contain no-lapse guarantee provisions. For these policies, we establish a reserve in addition to the account balance, based on expected no-lapse guarantee benefits and expected policy assessments.

This table summarizes our life policy and investment contract reserves:



(In millions)	June 30, 2013		December 31, 2012
Ordinary/traditional life	$	778	$	752
Universal life	501		483
Deferred annuities	858		850
Structured settlements	192		193
Other	16		17
Total life policy and investment contract reserves	$	2,345	$	2,295

Deferred Acquisition Costs

6 Months Ended

Jun. 30, 2013

Deferred Costs [Abstract]

Deferred Acquisition Costs

DEFERRED ACQUISITION COSTS

Expenses directly related to successfully acquiring insurance policies – primarily commissions, premium taxes and underwriting costs – are deferred and amortized over the terms of the policies. We update our acquisition cost assumptions periodically to reflect actual experience, and we evaluate the costs for recoverability. The table below shows the deferred policy acquisition costs and asset reconciliation.



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Deferred policy acquisition costs asset at beginning of period	$	491		$	483		$	470		$	477
Capitalized deferred policy acquisition costs	203			192			401			362
Amortized deferred policy acquisition costs	(183		)	(181		)	(362		)	(337		)
Amortized shadow deferred policy acquisition costs	35			(10		)	37			(18		)
Deferred policy acquisition costs asset at end of period	$	546		$	484		$	546		$	484

No premium deficiencies were recorded in the condensed consolidated statements of income, as the sum of the anticipated loss and loss adjustment expenses, policyholder dividends and unamortized deferred acquisition expenses did not exceed the related unearned premiums and anticipated investment income.

Accumulated Other Comprehensive Income

6 Months Ended

Jun. 30, 2013

Accumulated Other Comprehensive Income [Abstract]

Comprehensive Income (Loss) Note

ACCUMULATED OTHER COMPREHENSIVE INCOME

Accumulated other comprehensive income includes changes in unrealized gains and losses on available for sale investments and other invested assets, changes in pension obligations and changes in life deferred acquisition costs, life policy reserves and other as follows:



(In millions)	Three months ended June 30,
	2013									2012
	Before tax			Income tax			Net			Before tax			Income tax			Net
Accumulated unrealized gains, net, on investments available for sale, beginning of period	$	2,231		$	771		$	1,460		$	1,717		$	592		$	1,125

Other comprehensive income before reclassification	(230		)	(81		)	(149		)	(47		)	(17		)	(30		)
Reclassification adjustment for realized investment gains, net, included in net income	(14		)	(4		)	(10		)	(6		)	(2		)	(4		)
Effect on other comprehensive income	(244		)	(85		)	(159		)	(53		)	(19		)	(34		)
Accumulated unrealized gains, net, on investments available for sale, end of period	$	1,987		$	686		$	1,301		$	1,664		$	573		$	1,091

Accumulated unrealized losses, net, for pension obligations, beginning of period	$	(99	)	$	(34	)	$	(65	)	$	(86	)	$	(30	)	$	(56	)
Other comprehensive income before reclassification	—			—			—			—			—			—
Reclassification adjustment for amortization of actuarial loss and prior service cost, net, included in net income	3			1			2			1			—			1
Effect on other comprehensive income	3			1			2			1			—			1
Accumulated unrealized losses, net, for pension obligations, end of period	$	(96	)	$	(33	)	$	(63	)	$	(85	)	$	(30	)	$	(55	)

Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, beginning of period	$	(50	)	$	(17	)	$	(33	)	$	(34	)	$	(12	)	$	(22	)
Effect on other comprehensive income	24			8			16			(5		)	(1		)	(4		)
Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, end of period	$	(26	)	$	(9	)	$	(17	)	$	(39	)	$	(13	)	$	(26	)

Accumulated other comprehensive income, beginning of period	$	2,082		$	720		$	1,362		$	1,597		$	550		$	1,047
Change in unrealized gains, net, on investments available for sale	(244		)	(85		)	(159		)	(53		)	(19		)	(34		)
Change in pension obligations	3			1			2			1			—			1
Change in life deferred acquisition costs, life policy reserves and other	24			8			16			(5		)	(1		)	(4		)
Effect on other comprehensive income	(217		)	(76		)	(141		)	(57		)	(20		)	(37		)
Accumulated other comprehensive income, end of period	$	1,865		$	644		$	1,221		$	1,540		$	530		$	1,010



(In millions)	Six months ended June 30,
	2013									2012
	Before tax			Income tax			Net			Before tax			Income tax			Net
Accumulated unrealized gains, net, on investments available for sale, beginning of period	$	1,875		$	647		$	1,228		$	1,489		$	512		$	977

Other comprehensive income before reclassification	164			56			108			194			67			127
Reclassification adjustment for realized investment gains, net, included in net income	(52		)	(17		)	(35		)	(19		)	(6		)	(13		)
Effect on other comprehensive income	112			39			73			175			61			114
Accumulated unrealized gains, net, on investments available for sale, end of period	$	1,987		$	686		$	1,301		$	1,664		$	573		$	1,091

Accumulated unrealized losses, net, for pension obligations, beginning of period	$	(101	)	$	(35	)	$	(66	)	$	(88	)	$	(31	)	$	(57	)
Other comprehensive income before reclassification	—			—			—			—			—			—
Reclassification adjustment for amortization of actuarial loss and prior service cost, net, included in net income	5			2			3			3			1			2
Effect on other comprehensive income	5			2			3			3			1			2
Accumulated unrealized losses, net, for pension obligations, end of period	$	(96	)	$	(33	)	$	(63	)	$	(85	)	$	(30	)	$	(55	)

Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, beginning of period	$	(50	)	$	(17	)	$	(33	)	$	(29	)	$	(10	)	$	(19	)
Other comprehensive income before reclassification	27			10			17			(10		)	(3		)	(7		)
Reclassification adjustment for life deferred acquisition costs, life policy reserves and other, net, included in net income	(3		)	(2		)	(1		)	—			—			—
Effect on other comprehensive income	24			8			16			(10		)	(3		)	(7		)
Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, end of period	$	(26	)	$	(9	)	$	(17	)	$	(39	)	$	(13	)	$	(26	)

Accumulated other comprehensive income, beginning of period	$	1,724		$	595		$	1,129		$	1,372		$	471		$	901
Change in unrealized gains, net, on investments available for sale	112			39			73			175			61			114
Change in pension obligations	5			2			3			3			1			2
Change in life deferred acquisition costs, life policy reserves and other	24			8			16			(10		)	(3		)	(7		)
Effect on other comprehensive income	141			49			92			168			59			109
Accumulated other comprehensive income, end of period	$	1,865		$	644		$	1,221		$	1,540		$	530		$	1,010

The reclassification adjustment for realized gains on investments available for sale are recorded in the total realized investment gains, net, line item of the condensed consolidated statements of income. The reclassification adjustment for amortization of actuarial loss and prior service cost, net, are recorded in the insurance losses and policyholder benefits, underwriting, acquisition and insurance expenses and the other operating expenses line items of the condensed consolidated statements of income.

Reinsurance

6 Months Ended

Jun. 30, 2013

Reinsurance Disclosures [Abstract]

Reinsurance

REINSURANCE

Reinsurance mitigates the risk of highly uncertain exposures and limits the maximum net loss that can arise from large risks or risks concentrated in areas of exposure. Management's decisions about the appropriate level of risk retention are affected by various factors, including changes in our underwriting practices, capacity to retain risks and reinsurance market conditions. Primary components of our property and casualty reinsurance program include a property per risk treaty, property excess treaty, casualty per occurrence treaty, casualty excess treaty, property catastrophe treaty and catastrophe bonds.

Our condensed consolidated statements of income include earned consolidated property casualty insurance premiums on assumed and ceded business:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Direct earned premiums	$	958		$	868		$	1,893		$	1,707
Assumed earned premiums	3			3			5			6
Ceded earned premiums	(51		)	(45		)	(99		)	(89		)
Net earned premiums	$	910		$	826		$	1,799		$	1,624

Our condensed consolidated statements of income include incurred consolidated property casualty insurance loss and loss expenses on assumed and ceded business:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Direct incurred loss and loss expenses	$	593		$	647		$	1,128		$	1,183
Assumed incurred loss and loss expenses	5			1			7			6
Ceded incurred loss and loss expenses	(15		)	(8		)	(28		)	(10		)
Net incurred loss and loss expenses	$	583		$	640		$	1,107		$	1,179

Our life insurance company purchases reinsurance for protection of a portion of the risk that is written. Primary components of our life reinsurance program include individual mortality coverage and aggregate catastrophe and accidental death coverage in excess of certain deductibles.

Our condensed consolidated statements of income include earned life insurance premiums on ceded business:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Direct earned premiums	$	58		$	64		$	114		$	118
Assumed earned premiums	—			—			—			—
Ceded earned premiums	(14		)	(13		)	(28		)	(26		)
Net earned premiums	$	44		$	51		$	86		$	92

Our condensed consolidated statements of income include life insurance policyholders’ benefits incurred on ceded business:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Direct policyholders' benefits incurred	$	62		$	57		$	126		$	110
Assumed policyholders' benefits incurred	—			—			—			—
Ceded policyholders' benefits incurred	(14		)	(10		)	(34		)	(20		)
Net policyholders' benefits incurred	$	48		$	47		$	92		$	90

The ceded benefits incurred can vary depending on the type of life insurance policy held and the year the policy was sold.

Income Taxes

6 Months Ended

Jun. 30, 2013

Income Tax Disclosure [Abstract]

Income Taxes

INCOME TAXES

As of June 30, 2013, and December 31, 2012, we had no liability for unrecognized tax benefits. Details about our liability for unrecognized tax benefits are found in our 2012 Annual Report on Form 10-K, Item 8, Note 11, Income Taxes, Page 129.

The differences between the 35 percent statutory income tax rate and our effective income tax rate were as follows:



(Dollars in millions)	Three months ended June 30,										Six months ended June 30,
	2013					2012					2013					2012
Tax at statutory rate	$	52		35.0	%	$	10		35.0	%	$	128		35.0	%	$	49		35.0	%
Increase (decrease) resulting from:
Tax-exempt income from municipal bonds	(9		)	(6.1	)	(8		)	(27.6	)	(16		)	(4.4	)	(17		)	(12.1	)
Dividend received exclusion	(6		)	(4.2	)	(6		)	(20.7	)	(12		)	(3.3	)	(11		)	(7.8	)
Other	1			1.0		1			3.0		1			0.4		2			1.2
Provision (benefit) for income taxes	$	38		25.7	%	$	(3	)	(10.3	)%	$	101		27.7	%	$	23		16.3	%

The change in our effective tax rate was primarily due to changes in pretax income from underwriting results and realized investment gains and losses, compared with unchanged levels of permanent book-tax differences.

Net Income Per Common Share

6 Months Ended

Jun. 30, 2013

Earnings Per Share [Abstract]

Net Income Per Common Share

NET INCOME PER COMMON SHARE

Basic earnings per share are computed based on the weighted average number of shares outstanding. Diluted earnings per share are computed based on the weighted average number of common and dilutive potential common shares outstanding using the treasury stock method.

The table shows calculations for basic and diluted earnings per share:



(Dollars in millions except share data in thousands)	Three months ended June 30,				Six months ended June 30,
(Dollars in millions except share data in thousands)	2013		2012		2013		2012
Numerator:
Net income—basic and diluted	$	110	$	32	$	264	$	118
Denominator:
Weighted-average common shares outstanding	163,512		162,425		163,323		162,351
Effect of stock-based awards:
Stock options	1,239		419		1,098		375
Nonvested shares	691		670		730		602
Adjusted weighted-average shares	165,442		163,514		165,151		163,328
Earnings per share:
Basic	$	0.67	$	0.20	$	1.62	$	0.73
Diluted	0.66		0.20		1.60		0.72
Number of anti-dilutive stock-based awards	340		6,059		393		6,072

The current sources of dilution of our common shares are certain equity-based awards as discussed in our 2012 Annual Report on Form 10-K, Item 8, Note 17, Stock-Based Associate Compensation Plans, Page 135. The above table shows the number of anti-dilutive stock-based awards for the three and six months ended June 30, 2013 and 2012. We did not include these stock-based awards in the computation of net income per common share (diluted) because their exercise would have anti-dilutive effects.

Employee Retirement Benefits

6 Months Ended

Jun. 30, 2013

Compensation and Retirement Disclosure [Abstract]

Employee Retirement Benefits

EMPLOYEE RETIREMENT BENEFITS

The following summarizes the components of net periodic costs for our qualified and supplemental pension plans:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Service cost	$	3		$	3		$	6		$	6
Interest cost	3			4			6			7
Expected return on plan assets	(4		)	(4		)	(8		)	(8		)
Amortization of actuarial loss and prior service cost	3			1			5			3
Net periodic benefit cost	$	5		$	4		$	9		$	8

See our 2012 Annual Report on Form 10-K, Item 8, Note 13, Employee Retirement Benefits, Page 130, for information on our retirement benefits. We made matching contributions of $2 million and $3 million to our 401(k) and Top Hat savings plans during the second quarter of 2013 and 2012 and contributions of $5 million for the first six months of 2013 and 2012, respectively.

We contributed $15 million to our qualified pension plan during the first quarter of 2013. We do not anticipate further contributions to our qualified pension plan during the remainder of 2013.

Commitments and Contingent Liabilities	6 Months Ended
Commitments and Contingent Liabilities	Jun. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingent Liabilities	COMMITMENTS AND CONTINGENT LIABILITIES In the ordinary course of conducting business, the company and its subsidiaries are named as defendants in various legal proceedings. Most of these proceedings are claims litigation involving the company's insurance subsidiaries in which the company is either defending or providing indemnity for third-party claims brought against insureds or litigating first-party coverage claims. The company accounts for such activity through the establishment of unpaid loss and loss adjustment expense reserves. We believe that the ultimate liability, if any, with respect to such ordinary-course claims litigation, after consideration of provisions made for potential losses and costs of defense, is immaterial to our consolidated financial condition, results of operations and cash flows. The company and its subsidiaries also are occasionally involved in other legal and regulatory proceedings, some of which assert claims for substantial amounts. These actions include, among others, putative class actions seeking certification of a state or national class. Such proceedings have alleged, for example, breach of an alleged duty to search national data bases to ascertain unreported deaths of insureds under life insurance policies. The company's insurance subsidiaries also are occasionally parties to individual actions in which extra-contractual damages, punitive damages or penalties are sought, such as claims alleging bad faith handling of insurance claims or writing unauthorized coverage and claims alleging discrimination by former associates. On a quarterly basis, we review these outstanding matters. Under current accounting guidance, we establish accruals when it is probable that a loss has been incurred and we can reasonably estimate its potential exposure. The company accounts for such probable and estimable losses, if any, through the establishment of legal expense reserves. Based on our quarterly review, we believe that our accruals for probable and estimable losses are reasonable and that the amounts accrued do not have a material effect on our consolidated financial condition or results of operations. However, if any one or more of these matters results in a judgment against us or settlement for an amount that is significantly greater than the amount accrued, the resulting liability could have a material effect on the company's consolidated results of operations or cash flows. Based on our most recent review, our estimate for any other matters for which the risk of loss is not probable, but more than remote is less than $2 million.

Segment Information

6 Months Ended

Jun. 30, 2013

Segment Reporting [Abstract]

Segment Information

SEGMENT INFORMATION

We operate primarily in two industries, property casualty insurance and life insurance. We regularly review our reporting segments to make decisions about allocating resources and assessing performance:


•	Commercial lines property casualty insurance


•	Personal lines property casualty insurance


•	Excess and surplus lines property casualty insurance


•	Life insurance


•	Investments

We report as Other the noninvestment operations of the parent company and its noninsurer subsidiary, CFC Investment Company. See our 2012 Annual Report on Form 10-K, Item 8, Note 18, Segment Information, Page 137, for a description of revenue, income or loss before income taxes and identifiable assets for each of the five segments.

Segment information is summarized in the following table:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Revenues:
Commercial lines insurance
Commercial casualty	$	211		$	191		$	415		$	372
Commercial property	152			134			299			265
Commercial auto	117			106			231			207
Workers' compensation	87			85			175			166
Specialty packages	37			37			76			75
Surety and executive risk	30			27			59			54
Machinery and equipment	11			10			21			19
Commercial lines insurance premiums	645			590			1,276			1,158
Fee revenue	1			1			1			2
Total commercial lines insurance	646			591			1,277			1,160
Personal lines insurance
Personal auto	109			100			216			198
Homeowner	99			87			195			171
Other personal lines	29			27			57			54
Personal lines insurance premiums	237			214			468			423
Fee revenue	1			1			1			1
Total personal lines insurance	238			215			469			424

Excess and surplus lines insurance	28			22			55			43

Life insurance	44			51			86			92
Separate account investment management fees	1			—			2			—
Total life insurance	45			51			88			92

Investment operations
Investment income, net of expenses	131			132			259			263
Realized investment gains, net	14			6			55			19
Total investment revenue	145			138			314			282

Other	2			3			4			5
Total revenues	$	1,104		$	1,020		$	2,207		$	2,006
Income (loss) before income taxes:
Insurance underwriting results
Commercial lines insurance	$	34		$	(20	)	$	92		$	14
Personal lines insurance	(1		)	(55		)	19			(77		)
Excess and surplus lines insurance	1			(2		)	1			(5		)
Life insurance	3			2			10			(1		)
Investment operations	127			118			275			241
Other	(16		)	(14		)	(32		)	(31		)
Total	$	148		$	29		$	365		$	141



Identifiable assets:	June 30, 2013		December 31, 2012
Property casualty insurance	$	2,489	$	2,395
Life insurance	1,254		1,201
Investment operations	12,983		12,599
Other	308		353
Total	$	17,034	$	16,548

Accounting Policies (Policies)	6 Months Ended
Accounting Policies (Policies)	Jun. 30, 2013
Accounting Policies [Abstract]
Adopted Accounting Updates, Policy	ASU 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income In February 2013, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. ASU 2013-02 requires entities to present in either a single note or parenthetically on the face of the financial statements, the effect of significant amounts reclassified from each component of accumulated other comprehensive income based on its source and the income statement line items affected by the reclassification. The company adopted this ASU during the first quarter of 2013, and it did not have a material impact on our company’s financial position, cash flows or results of operations. See Note 7, Accumulated Other Comprehensive Income, for further details.

Investments (Tables)

6 Months Ended

Jun. 30, 2013

Investments [Abstract]

Analysis Of Cost Or Amortized Cost, Gross Unrealized Gains And Losses And Fair Value for Investments

The following table provides cost or amortized cost, gross unrealized gains, gross unrealized losses and fair value for our invested assets:



(In millions)	Cost or
	amortized		Gross unrealized				Fair
At June 30, 2013	cost		gains		losses		value
Fixed maturities:
States, municipalities and political subdivisions	$	3,044	$	162	$	18	$	3,188
Convertibles and bonds with warrants attached	16		—		—		16
United States government	7		—		—		7
Government-sponsored enterprises	208		—		13		195
Foreign government	10		—		—		10
Commercial mortgage-backed securities	63		—		3		60
Corporate securities	5,080		459		23		5,516
Subtotal	8,428		621		57		8,992
Equity securities:
Common equities	2,375		1,398		12		3,761
Preferred equities	77		37		—		114
Subtotal	2,452		1,435		12		3,875
Total	$	10,880	$	2,056	$	69	$	12,867
At December 31, 2012
Fixed maturities:
States, municipalities and political subdivisions	$	3,040	$	250	$	1	$	3,289
Convertibles and bonds with warrants attached	31		—		—		31
United States government	7		1		—		8
Government-sponsored enterprises	164		—		—		164
Foreign government	3		—		—		3
Commercial mortgage-backed securities	27		1		—		28
Corporate securities	4,950		622		2		5,570
Subtotal	8,222		874		3		9,093
Equity securities:
Common equities	2,270		977		9		3,238
Preferred equities	99		37		1		135
Subtotal	2,369		1,014		10		3,373
Total	$	10,591	$	1,888	$	13	$	12,466

Fair Values And Unrealized Losses by Investment Category And By The Duration Of The Securities' Continuous Unrealized Loss Position

The table below provides fair values and unrealized losses by investment category and by the duration of the securities’ continuous unrealized loss position:



(In millions)	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
At June 30, 2013	value		losses		value		losses		value		losses
Fixed maturities:
States, municipalities and political subdivisions	$	377	$	18	$	—	$	—	$	377	$	18
United States government	1		—		—		—		1		—
Foreign government	10		—		—		—		10		—
Government-sponsored enterprises	185		13		—		—		185		13
Commercial mortgage-backed securities	51		3		—		—		51		3
Corporate securities	580		22		13		1		593		23
Subtotal	1,204		56		13		1		1,217		57
Equity securities:
Common equities	202		12		—		—		202		12
Preferred equities	4		—		—		—		4		—
Subtotal	206		12		—		—		206		12
Total	$	1,410	$	68	$	13	$	1	$	1,423	$	69
At December 31, 2012
Fixed maturities:
States, municipalities and political subdivisions	$	53	$	1	$	—	$	—	$	53	$	1
Government-sponsored enterprises	1		—		—		—		1		—
Corporate securities	58		1		17		1		75		2
Subtotal	112		2		17		1		129		3
Equity securities:
Common equities	107		9		—		—		107		9
Preferred equities	4		1		—		—		4		1
Subtotal	111		10		—		—		111		10
Total	$	223	$	12	$	17	$	1	$	240	$	13

Investment Income, Realized Investment Gains And Losses And Change In Unrealized Investment Gains And Losses

The following table provides investment income, realized investment gains and losses and the change in unrealized investment gains and losses and other items:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Investment income summary:
Interest on fixed maturities	$	103		$	106		$	205		$	212
Dividends on equity securities	30			27			57			53
Other investment income	—			1			1			2
Total	133			134			263			267
Less investment expenses	2			2			4			4
Total	$	131		$	132		$	259		$	263

Realized investment gains and losses summary:
Fixed maturities:
Gross realized gains	$	2		$	13		$	4		$	16
Gross realized losses	—			—			—			—
Other-than-temporary impairments	—			—			(2		)	—
Equity securities:
Gross realized gains	12			6			49			29
Gross realized losses	—			(1		)	—			(1		)
Other-than-temporary impairments	—			(14		)	—			(30		)
Securities with embedded derivatives	—			1			1			5
Other	—			1			3			—
Total	$	14		$	6		$	55		$	19

Change in unrealized gains and losses summary:
Fixed maturities	$	(282	)	$	29		$	(307	)	$	78
Equity securities	38			(82		)	419			97
Adjustment to deferred acquisition costs and life policy reserves	26			(8		)	29			(15		)
Amortization of pension actuarial loss and prior service cost	3			1			5			3
Other	(2		)	3			(5		)	5
Income taxes on above	76			20			(49		)	(59		)
Total	$	(141	)	$	(37	)	$	92		$	109

Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2013

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Fair Value Hierarchy for Assets Measured at Fair Value on a Recurring Basis



(In millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At June 30, 2013			Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
Fixed maturities, available for sale:
States, municipalities and political subdivisions	$	—	$	3,187	$	1	$	3,188
Convertibles and bonds with warrants attached	—		16		—		16
United States government	7		—		—		7
Government-sponsored enterprises	—		195		—		195
Foreign government	—		10		—		10
Commercial mortgage-backed securities	—		60		—		60
Corporate securities	—		5,513		3		5,516
Subtotal	7		8,981		4		8,992
Common equities, available for sale	3,761		—		—		3,761
Preferred equities, available for sale	—		112		2		114
Taxable fixed maturities separate accounts	—		693		—		693
Top Hat Savings Plan (included in Other assets)	11		—		—		11
Total	$	3,779	$	9,786	$	6	$	13,571
At December 31, 2012
Fixed maturities, available for sale:
States, municipalities and political subdivisions	$	—	$	3,288	$	1	$	3,289
Convertibles and bonds with warrants attached	—		31		—		31
United States government	8		—		—		8
Government-sponsored enterprises	—		164		—		164
Foreign government	—		3		—		3
Commercial mortgage-backed securities	—		28		—		28
Corporate securities	—		5,567		3		5,570
Subtotal	8		9,081		4		9,093
Common equities, available for sale	3,238		—		—		3,238
Preferred equities, available for sale	—		134		1		135
Taxable fixed-maturities separate accounts	—		689		—		689
Top Hat Savings Plan (included in Other assets)	9		—		—		9
Total	$	3,255	$	9,904	$	5	$	13,164

Asset Fair Value Measurements Using Significant Unobservable Inputs (Level 3)

The following tables provide the change in Level 3 assets for the three months ended June 30:




(In millions)	Corporate fixed maturities			States, municipalities and political subdivisions fixed maturities		Preferred equities		Total
Beginning balance, March 31, 2013	$	3		$	1	$	2	$	6
Total gains or losses (realized/unrealized):
Included in earnings	—			—		—		—
Included in other comprehensive income	—			—		—		—
Purchases	—			—		—		—
Sales	—			—		—		—
Transfers into Level 3	—			—		—		—
Transfers out of Level 3	—			—		—		—
Ending balance, June 30, 2013	$	3		$	1	$	2	$	6

Beginning balance, March 31, 2012	$	16		$	2	$	7	$	25
Total gains or losses (realized/unrealized):
Included in earnings	—			—		—		—
Included in other comprehensive income	—			—		—		—
Purchases	—			—		—		—
Sales	(1		)	—		—		(1		)
Transfers into Level 3	—			—		—		—
Transfers out of Level 3	(11		)	—		—		(11		)
Ending balance, June 30, 2012	$	4		$	2	$	7	$	13

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]

This table summarizes the book value and principal amounts of our long-term debt:



(In millions)				Book value				Principal amount
				June 30,		December 31,		June 30,		December 31,
Interest rate		Year of issue		2013		2012		2013		2012
6.900	%	1998	Senior debentures, due 2028	$	28	$	28	$	28	$	28
6.920	%	2005	Senior debentures, due 2028	391		391		391		391
6.125	%	2004	Senior notes, due 2034	371		371		374		374
			Total	$	790	$	790	$	793	$	793

Fair Value of Life Policy Loans

The following table shows the fair value of our life policy loans, included in other invested assets, subject to fair value disclosure requirements:



(In millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At June 30, 2013			Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
Life policy loans	$	—	$	—	$	46	$	46

At December 31, 2012
Life policy loans	$	—	$	—	$	50	$	50

Debt

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Fair Values of Deferred Annuities, Structured Settlements and Other Items

The following table shows fair values of our note payable and long-term debt subject to fair value disclosure requirements:



(In millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At June 30, 2013			Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
Note payable	$	—	$	104	$	—	$	104
6.900% senior debentures, due 2028	—		33		—		33
6.920% senior debentures, due 2028	—		469		—		469
6.125% senior notes, due 2034	—		402		—		402
Total	$	—	$	1,008	$	—	$	1,008

At December 31, 2012
Note payable	$	—	$	104	$	—	$	104
6.900% senior debentures, due 2028	—		31		—		31
6.920% senior debentures, due 2028	—		479		—		479
6.125% senior notes, due 2034	—		431		—		431
Total	$	—	$	1,045	$	—	$	1,045

Deferred Annuities, Structured Settlements, And Other

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Fair Values of Deferred Annuities, Structured Settlements and Other Items

The following table shows fair values of our deferred annuities and structured settlements, included in life policy and investment contract reserves, subject to fair value disclosure requirements:



(In millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At June 30, 2013			Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
Deferred annuities	$	—	$	—	$	887	$	887
Structured settlements	—		227		—		227
Total	$	—	$	227	$	887	$	1,114

At December 31, 2012
Deferred annuities	$	—	$	—	$	898	$	898
Structured settlements	—		240		—		240
Total	$	—	$	240	$	898	$	1,138

Property Casualty Loss and Loss Expenses (Tables)

6 Months Ended

Jun. 30, 2013

Premiums Written, Net [Abstract]

Consolidated Property Casualty Loss And Loss Expense Reserves

This table summarizes activity for our consolidated property casualty loss and loss expense reserves:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Gross loss and loss expense reserves, beginning of period	$	4,173		$	4,289		$	4,169		$	4,280
Less reinsurance receivable	349			352			356			375
Net loss and loss expense reserves, beginning of period	3,824			3,937			3,813			3,905
Net incurred loss and loss expenses related to:
Current accident year	675			725			1,209			1,380
Prior accident years	(92		)	(85		)	(102		)	(201		)
Total incurred	583			640			1,107			1,179
Net paid loss and loss expenses related to:
Current accident year	249			282			370			414
Prior accident years	272			290			664			665
Total paid	521			572			1,034			1,079
Net loss and loss expense reserves, end of period	3,886			4,005			3,886			4,005
Plus reinsurance receivable	333			332			333			332
Gross loss and loss expense reserves, end of period	$	4,219		$	4,337		$	4,219		$	4,337

Life Policy and Investment Contract Reserves (Tables)

6 Months Ended

Jun. 30, 2013

Liability for Future Policy Benefits [Abstract]

Reserve For Losses Loss Adjustment Expenses Table [Text Block]

This table summarizes our life policy and investment contract reserves:



(In millions)	June 30, 2013		December 31, 2012
Ordinary/traditional life	$	778	$	752
Universal life	501		483
Deferred annuities	858		850
Structured settlements	192		193
Other	16		17
Total life policy and investment contract reserves	$	2,345	$	2,295

Deferred Acquisition Costs (Tables)

6 Months Ended

Jun. 30, 2013

Deferred Costs [Abstract]

Deferred Policy Acquisition Costs And Asset Reconciliation, Including the Amortized Deferred Policy Acquisition Costs

The table below shows the deferred policy acquisition costs and asset reconciliation.



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Deferred policy acquisition costs asset at beginning of period	$	491		$	483		$	470		$	477
Capitalized deferred policy acquisition costs	203			192			401			362
Amortized deferred policy acquisition costs	(183		)	(181		)	(362		)	(337		)
Amortized shadow deferred policy acquisition costs	35			(10		)	37			(18		)
Deferred policy acquisition costs asset at end of period	$	546		$	484		$	546		$	484

Accumulated Other Comprehensive Income (Tables)

3 Months Ended

6 Months Ended

Jun. 30, 2013

Accumulated Other Comprehensive Income [Abstract]

Schedule of Accumulated Other Comprehensive Income (Loss)



(In millions)	Three months ended June 30,
	2013									2012
	Before tax			Income tax			Net			Before tax			Income tax			Net
Accumulated unrealized gains, net, on investments available for sale, beginning of period	$	2,231		$	771		$	1,460		$	1,717		$	592		$	1,125

Other comprehensive income before reclassification	(230		)	(81		)	(149		)	(47		)	(17		)	(30		)
Reclassification adjustment for realized investment gains, net, included in net income	(14		)	(4		)	(10		)	(6		)	(2		)	(4		)
Effect on other comprehensive income	(244		)	(85		)	(159		)	(53		)	(19		)	(34		)
Accumulated unrealized gains, net, on investments available for sale, end of period	$	1,987		$	686		$	1,301		$	1,664		$	573		$	1,091

Accumulated unrealized losses, net, for pension obligations, beginning of period	$	(99	)	$	(34	)	$	(65	)	$	(86	)	$	(30	)	$	(56	)
Other comprehensive income before reclassification	—			—			—			—			—			—
Reclassification adjustment for amortization of actuarial loss and prior service cost, net, included in net income	3			1			2			1			—			1
Effect on other comprehensive income	3			1			2			1			—			1
Accumulated unrealized losses, net, for pension obligations, end of period	$	(96	)	$	(33	)	$	(63	)	$	(85	)	$	(30	)	$	(55	)

Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, beginning of period	$	(50	)	$	(17	)	$	(33	)	$	(34	)	$	(12	)	$	(22	)
Effect on other comprehensive income	24			8			16			(5		)	(1		)	(4		)
Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, end of period	$	(26	)	$	(9	)	$	(17	)	$	(39	)	$	(13	)	$	(26	)

Accumulated other comprehensive income, beginning of period	$	2,082		$	720		$	1,362		$	1,597		$	550		$	1,047
Change in unrealized gains, net, on investments available for sale	(244		)	(85		)	(159		)	(53		)	(19		)	(34		)
Change in pension obligations	3			1			2			1			—			1
Change in life deferred acquisition costs, life policy reserves and other	24			8			16			(5		)	(1		)	(4		)
Effect on other comprehensive income	(217		)	(76		)	(141		)	(57		)	(20		)	(37		)
Accumulated other comprehensive income, end of period	$	1,865		$	644		$	1,221		$	1,540		$	530		$	1,010



(In millions)	Six months ended June 30,
	2013									2012
	Before tax			Income tax			Net			Before tax			Income tax			Net
Accumulated unrealized gains, net, on investments available for sale, beginning of period	$	1,875		$	647		$	1,228		$	1,489		$	512		$	977

Other comprehensive income before reclassification	164			56			108			194			67			127
Reclassification adjustment for realized investment gains, net, included in net income	(52		)	(17		)	(35		)	(19		)	(6		)	(13		)
Effect on other comprehensive income	112			39			73			175			61			114
Accumulated unrealized gains, net, on investments available for sale, end of period	$	1,987		$	686		$	1,301		$	1,664		$	573		$	1,091

Accumulated unrealized losses, net, for pension obligations, beginning of period	$	(101	)	$	(35	)	$	(66	)	$	(88	)	$	(31	)	$	(57	)
Other comprehensive income before reclassification	—			—			—			—			—			—
Reclassification adjustment for amortization of actuarial loss and prior service cost, net, included in net income	5			2			3			3			1			2
Effect on other comprehensive income	5			2			3			3			1			2
Accumulated unrealized losses, net, for pension obligations, end of period	$	(96	)	$	(33	)	$	(63	)	$	(85	)	$	(30	)	$	(55	)

Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, beginning of period	$	(50	)	$	(17	)	$	(33	)	$	(29	)	$	(10	)	$	(19	)
Other comprehensive income before reclassification	27			10			17			(10		)	(3		)	(7		)
Reclassification adjustment for life deferred acquisition costs, life policy reserves and other, net, included in net income	(3		)	(2		)	(1		)	—			—			—
Effect on other comprehensive income	24			8			16			(10		)	(3		)	(7		)
Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, end of period	$	(26	)	$	(9	)	$	(17	)	$	(39	)	$	(13	)	$	(26	)

Accumulated other comprehensive income, beginning of period	$	1,724		$	595		$	1,129		$	1,372		$	471		$	901
Change in unrealized gains, net, on investments available for sale	112			39			73			175			61			114
Change in pension obligations	5			2			3			3			1			2
Change in life deferred acquisition costs, life policy reserves and other	24			8			16			(10		)	(3		)	(7		)
Effect on other comprehensive income	141			49			92			168			59			109
Accumulated other comprehensive income, end of period	$	1,865		$	644		$	1,221		$	1,540		$	530		$	1,010

Reinsurance (Tables)

6 Months Ended

Jun. 30, 2013

Reinsurance Disclosures [Abstract]

Earned Consolidated Property Casualty Insurance Premiums On Assumed And Ceded Business

Our condensed consolidated statements of income include earned consolidated property casualty insurance premiums on assumed and ceded business:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Direct earned premiums	$	958		$	868		$	1,893		$	1,707
Assumed earned premiums	3			3			5			6
Ceded earned premiums	(51		)	(45		)	(99		)	(89		)
Net earned premiums	$	910		$	826		$	1,799		$	1,624

Incurred Consolidated Property Casualty Insurance Loss And Loss Expenses On Assumed And Ceded Business

Our condensed consolidated statements of income include incurred consolidated property casualty insurance loss and loss expenses on assumed and ceded business:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Direct incurred loss and loss expenses	$	593		$	647		$	1,128		$	1,183
Assumed incurred loss and loss expenses	5			1			7			6
Ceded incurred loss and loss expenses	(15		)	(8		)	(28		)	(10		)
Net incurred loss and loss expenses	$	583		$	640		$	1,107		$	1,179

Earned Life Insurance Premiums On Ceded Business

Our condensed consolidated statements of income include earned life insurance premiums on ceded business:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Direct earned premiums	$	58		$	64		$	114		$	118
Assumed earned premiums	—			—			—			—
Ceded earned premiums	(14		)	(13		)	(28		)	(26		)
Net earned premiums	$	44		$	51		$	86		$	92

Life Insurance Contract Holders' Benefits Incurred On Ceded Business

Our condensed consolidated statements of income include life insurance policyholders’ benefits incurred on ceded business:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Direct policyholders' benefits incurred	$	62		$	57		$	126		$	110
Assumed policyholders' benefits incurred	—			—			—			—
Ceded policyholders' benefits incurred	(14		)	(10		)	(34		)	(20		)
Net policyholders' benefits incurred	$	48		$	47		$	92		$	90

Income Taxes (Tables)

6 Months Ended

Jun. 30, 2013

Income Tax Disclosure [Abstract]

Differences Between The 35 Percent Statutory Income Tax Rate And Effective Income Tax Rate

The differences between the 35 percent statutory income tax rate and our effective income tax rate were as follows:



(Dollars in millions)	Three months ended June 30,										Six months ended June 30,
	2013					2012					2013					2012
Tax at statutory rate	$	52		35.0	%	$	10		35.0	%	$	128		35.0	%	$	49		35.0	%
Increase (decrease) resulting from:
Tax-exempt income from municipal bonds	(9		)	(6.1	)	(8		)	(27.6	)	(16		)	(4.4	)	(17		)	(12.1	)
Dividend received exclusion	(6		)	(4.2	)	(6		)	(20.7	)	(12		)	(3.3	)	(11		)	(7.8	)
Other	1			1.0		1			3.0		1			0.4		2			1.2
Provision (benefit) for income taxes	$	38		25.7	%	$	(3	)	(10.3	)%	$	101		27.7	%	$	23		16.3	%

Net Income Per Common Share (Tables)

6 Months Ended

Jun. 30, 2013

Earnings Per Share [Abstract]

Calculations For Basic And Diluted Earnings Per Share

The table shows calculations for basic and diluted earnings per share:



(Dollars in millions except share data in thousands)	Three months ended June 30,				Six months ended June 30,
(Dollars in millions except share data in thousands)	2013		2012		2013		2012
Numerator:
Net income—basic and diluted	$	110	$	32	$	264	$	118
Denominator:
Weighted-average common shares outstanding	163,512		162,425		163,323		162,351
Effect of stock-based awards:
Stock options	1,239		419		1,098		375
Nonvested shares	691		670		730		602
Adjusted weighted-average shares	165,442		163,514		165,151		163,328
Earnings per share:
Basic	$	0.67	$	0.20	$	1.62	$	0.73
Diluted	0.66		0.20		1.60		0.72
Number of anti-dilutive stock-based awards	340		6,059		393		6,072

Employee Retirement Benefits (Tables)

6 Months Ended

Jun. 30, 2013

Compensation and Retirement Disclosure [Abstract]

Schedule of Defined Benefit Plans Disclosures

The following summarizes the components of net periodic costs for our qualified and supplemental pension plans:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Service cost	$	3		$	3		$	6		$	6
Interest cost	3			4			6			7
Expected return on plan assets	(4		)	(4		)	(8		)	(8		)
Amortization of actuarial loss and prior service cost	3			1			5			3
Net periodic benefit cost	$	5		$	4		$	9		$	8

Segment Information (Tables)

6 Months Ended

Jun. 30, 2013

Segment Reporting [Abstract]

Segment Information

Segment information is summarized in the following table:



(In millions)	Three months ended June 30,						Six months ended June 30,
	2013			2012			2013			2012
Revenues:
Commercial lines insurance
Commercial casualty	$	211		$	191		$	415		$	372
Commercial property	152			134			299			265
Commercial auto	117			106			231			207
Workers' compensation	87			85			175			166
Specialty packages	37			37			76			75
Surety and executive risk	30			27			59			54
Machinery and equipment	11			10			21			19
Commercial lines insurance premiums	645			590			1,276			1,158
Fee revenue	1			1			1			2
Total commercial lines insurance	646			591			1,277			1,160
Personal lines insurance
Personal auto	109			100			216			198
Homeowner	99			87			195			171
Other personal lines	29			27			57			54
Personal lines insurance premiums	237			214			468			423
Fee revenue	1			1			1			1
Total personal lines insurance	238			215			469			424

Excess and surplus lines insurance	28			22			55			43

Life insurance	44			51			86			92
Separate account investment management fees	1			—			2			—
Total life insurance	45			51			88			92

Investment operations
Investment income, net of expenses	131			132			259			263
Realized investment gains, net	14			6			55			19
Total investment revenue	145			138			314			282

Other	2			3			4			5
Total revenues	$	1,104		$	1,020		$	2,207		$	2,006
Income (loss) before income taxes:
Insurance underwriting results
Commercial lines insurance	$	34		$	(20	)	$	92		$	14
Personal lines insurance	(1		)	(55		)	19			(77		)
Excess and surplus lines insurance	1			(2		)	1			(5		)
Life insurance	3			2			10			(1		)
Investment operations	127			118			275			241
Other	(16		)	(14		)	(32		)	(31		)
Total	$	148		$	29		$	365		$	141



Identifiable assets:	June 30, 2013		December 31, 2012
Property casualty insurance	$	2,489	$	2,395
Life insurance	1,254		1,201
Investment operations	12,983		12,599
Other	308		353
Total	$	17,034	$	16,548

Investments - Analysis of Cost or Amortized Cost, Gross Unrealized Gains and Losses and Fair Value for Investments (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	$ 8,428	$ 8,222
Gross Unrealized Gains	621	874
Gross Unrealized Losses	57	3
Fair Value	8,992	9,093
Debt Securities \| States, Municipalities And Political Subdivisions
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	3,044	3,040
Gross Unrealized Gains	162	250
Gross Unrealized Losses	18	1
Fair Value	3,188	3,289
Debt Securities \| Convertibles And Bonds With Warrants Attached
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	16	31
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	16	31
Debt Securities \| United States Government
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	7	7
Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	0
Fair Value	7	8
Debt Securities \| Government-Sponsored Enterprises
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	208	164
Gross Unrealized Gains	0	0
Gross Unrealized Losses	13	0
Fair Value	195	164
Debt Securities \| Foreign Government
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	10	3
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	10	3
Debt Securities \| Commercial Mortgage Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	63	27
Gross Unrealized Gains	0	1
Gross Unrealized Losses	3	0
Fair Value	60	28
Debt Securities \| Corporate Securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	5,080	4,950
Gross Unrealized Gains	459	622
Gross Unrealized Losses	23	2
Fair Value	5,516	5,570
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	2,452	2,369
Gross Unrealized Gains	1,435	1,014
Gross Unrealized Losses	12	10
Fair Value	3,875	3,373
Equity Securities \| Common Stock
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	2,375	2,270
Gross Unrealized Gains	1,398	977
Gross Unrealized Losses	12	9
Fair Value	3,761	3,238
Equity Securities \| Preferred Stock
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	77	99
Gross Unrealized Gains	37	37
Gross Unrealized Losses	0	1
Fair Value	114	135
Fixed Maturities And Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	10,880	10,591
Gross Unrealized Gains	2,056	1,888
Gross Unrealized Losses	69	13
Fair Value	$ 12,867	$ 12,466

Investments - Fair Values and Unrealized Losses by Investment Category and by Duration of Securities' Continuous Unrealized Loss Position (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	$ 1,410	$ 223
Less than 12 months Unrealized Losses	68	12
12 months or more Fair Value	13	17
12 months or more Unrealized Losses	1	1
Total Fair Value	1,423	240
Total Unrealized Losses	69	13
Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	1,204	112
Less than 12 months Unrealized Losses	56	2
12 months or more Fair Value	13	17
12 months or more Unrealized Losses	1	1
Total Fair Value	1,217	129
Total Unrealized Losses	57	3
Fixed Maturities \| States, Municipalities And Political Subdivisions
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	377	53
Less than 12 months Unrealized Losses	18	1
12 months or more Fair Value	0	0
12 months or more Unrealized Losses	0	0
Total Fair Value	377	53
Total Unrealized Losses	18	1
Fixed Maturities \| Foreign Government Debt Securities [Member]
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	10
Less than 12 months Unrealized Losses	0
12 months or more Fair Value	0
12 months or more Unrealized Losses	0
Total Fair Value	10
Total Unrealized Losses	0
Fixed Maturities \| United States Government
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	1
Less than 12 months Unrealized Losses	0
12 months or more Fair Value	0
12 months or more Unrealized Losses	0
Total Fair Value	1
Total Unrealized Losses	0
Fixed Maturities \| Government-Sponsored Enterprises
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	185	1
Less than 12 months Unrealized Losses	13	0
12 months or more Fair Value	0	0
12 months or more Unrealized Losses	0	0
Total Fair Value	185	1
Total Unrealized Losses	13	0
Fixed Maturities \| Commercial Mortgage Backed Securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	51
Less than 12 months Unrealized Losses	3
12 months or more Fair Value	0
12 months or more Unrealized Losses	0
Total Fair Value	51
Total Unrealized Losses	3
Fixed Maturities \| Corporate Securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	580	58
Less than 12 months Unrealized Losses	22	1
12 months or more Fair Value	13	17
12 months or more Unrealized Losses	1	1
Total Fair Value	593	75
Total Unrealized Losses	23	2
Equity Securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	206	111
Less than 12 months Unrealized Losses	12	10
12 months or more Fair Value	0	0
12 months or more Unrealized Losses	0	0
Total Fair Value	206	111
Total Unrealized Losses	12	10
Equity Securities \| Common Stock
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	202	107
Less than 12 months Unrealized Losses	12	9
12 months or more Fair Value	0
12 months or more Unrealized Losses	0
Total Fair Value	202	107
Total Unrealized Losses	12	9
Equity Securities \| Preferred Stock
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	4	4
Less than 12 months Unrealized Losses	0	1
12 months or more Fair Value	0	0
12 months or more Unrealized Losses	0	0
Total Fair Value	4	4
Total Unrealized Losses	$ 0	$ 1

Investments - Realized Investment Gains and Losses and Change in Unrealized Investment Gains and Losses and Other Items (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Investment income summary:
Interest on fixed maturities	$ 103	$ 106	$ 205	$ 212
Dividends on equity securities	30	27	57	53
Other investment income	0	1	1	2
Total	133	134	263	267
Less investment expenses	2	2	4	4
Total	131	132	259	263
Realized investment gains and losses summary:
Other	(2)	3	(5)	5
Realized gains on investments	14	6	55	19
Change in unrealized gains and losses summary:
Unrealized gains (losses) on investments available-for-sale	(159)	(34)	73	114
Adjustment to deferred acquisition costs and life policy reserves	26	(8)	29	(15)
Amortization of pension actuarial loss and prior service cost	3	1	5	3
Other	(2)	3	(5)	5
Income taxes on above	76	20	49	59
Other comprehensive income (loss), net of tax	(141)	(37)	92	109
Fixed Maturities
Realized investment gains and losses summary:
Gross realized gains	2	13	4	16
Gross realized losses	0	0	0	0
Other-than-temporary impairments	0	0	2	0
Change in unrealized gains and losses summary:
Unrealized gains (losses) on investments available-for-sale	(282)	29	(307)	78
Equity Securities
Realized investment gains and losses summary:
Gross realized gains	12	6	49	29
Gross realized losses	0	(1)	0	1
Other-than-temporary impairments	0	(14)	0	30
Securities with embedded derivatives	0	1	1	5
Other	0	1	3	0
Realized gains on investments	14	6
Change in unrealized gains and losses summary:
Unrealized gains (losses) on investments available-for-sale	38	(82)	419	97
Other	$ 0	$ 1	$ 3	$ 0

Investments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Gain (Loss) on Investments [Line Items]
Fixed maturities, fair value of hybrid securities	$ 16	$ 31
Impaired securities	0
12 months or more Unrealized Losses	1	1
Fixed maturity investments, Percentage of amortized costs	70.00%	70.00%
Investments in fair value, deposit with various states	13,571	13,164
Fixed Maturities
Gain (Loss) on Investments [Line Items]
Unrealized investment gains due to a net gain position	621	874
Number of securities total unrealized loss in an unrealized loss position for 12 months or more	4	4
12 months or more Unrealized Losses	1	1
Equity Securities
Gain (Loss) on Investments [Line Items]
Unrealized investment gains due to a net gain position	1,435	1,014
12 months or more Unrealized Losses	0	0
Procter And Gamble Company, Exxon Mobile Corporation And Chevron Corporation [Member]
Gain (Loss) on Investments [Line Items]
Unrealized investment gains due to a net gain position	$ 283
Common Stock
Gain (Loss) on Investments [Line Items]
Number of securities	3

Fair Value Measurements - Change in Level 3 Assets (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 6	$ 25	$ 5	$ 25
Total gains or losses (realized/unrealized):
Included in earnings	0	0	0	0
Included in other comprehensive income	0	0	0	5
Purchases	0	0	1	1
Sales	0	(1)	0	(5)
Transfers into Level 3	0	0	0	1
Transfers out of Level 3	0	(11)	0	(14)
Ending balance	6	13	6	13
Corporate Fixed Maturities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	3	16	3	18
Total gains or losses (realized/unrealized):
Included in earnings	0	0	0	0
Included in other comprehensive income	0	0	0	3
Purchases	0	0	0	0
Sales	0	(1)	0	(4)
Transfers into Level 3	0	0	0	1
Transfers out of Level 3	0	(11)	0	(14)
Ending balance	3	4	3	4
States, Municipalities And Political Subdivisions Fixed Maturities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1	2	1	3
Total gains or losses (realized/unrealized):
Included in earnings	0	0	0	0
Included in other comprehensive income	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	(1)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Ending balance	1	2	1	2
Preferred Equities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	2	7	1	4
Total gains or losses (realized/unrealized):
Included in earnings	0	0	0	0
Included in other comprehensive income	0	0	0	2
Purchases	0	0	1	1
Sales	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Ending balance	$ 2	$ 7	$ 2	$ 7

Fair Value Measurements - Summary of Book Value and Principal Amounts of Long-Term Debt (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Book value	$ 790	$ 790
Principal amount of debt	793	793
Senior Debentures 6.900% Due 2028
Debt Instrument [Line Items]
Interest rate	6.90%	6.90%
Debt issuance year	1998	1998
Book value	28	28
Principal amount of debt	28	28
Senior Debentures 6.920% Due 2028
Debt Instrument [Line Items]
Interest rate	6.92%	6.92%
Debt issuance year	2005	2005
Book value	391	391
Principal amount of debt	391	391
Senior Notes 6.152% Due 2034
Debt Instrument [Line Items]
Interest rate	6.125%	6.125%
Debt issuance year	2004	2004
Book value	371	371
Principal amount of debt	$ 374	$ 374

Fair Value Measurements - Fair Values of Note Payable and Long-Term Debt (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of note payable	$ 104	$ 104
Total	1,008	1,045
Senior Debentures 6.900 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	6.90%	6.90%
Debt instrument, year of maturity	2028	2028
Fair value of senior debt	33	31
Senior Debentures 6.920 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	6.92%	6.92%
Debt instrument, year of maturity	2028	2028
Fair value of senior debt	469	479
Senior Notes 6.125 % Due 2034
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	6.125%	6.125%
Debt instrument, year of maturity	2034	2034
Fair value of senior debt	402	431
Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of note payable	0	0
Total	0	0
Quoted prices in active markets for identical assets (Level 1) \| Senior Debentures 6.900 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	0	0
Quoted prices in active markets for identical assets (Level 1) \| Senior Debentures 6.920 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	0	0
Quoted prices in active markets for identical assets (Level 1) \| Senior Notes 6.125 % Due 2034
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	0	0
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of note payable	104	104
Total	1,008	1,045
Significant other observable inputs (Level 2) \| Senior Debentures 6.900 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	33	31
Significant other observable inputs (Level 2) \| Senior Debentures 6.920 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	469	479
Significant other observable inputs (Level 2) \| Senior Notes 6.125 % Due 2034
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	402	431
Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of note payable	0	0
Total	0	0
Significant unobservable inputs (Level 3) \| Senior Debentures 6.900 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	0	0
Significant unobservable inputs (Level 3) \| Senior Debentures 6.920 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	0	0
Significant unobservable inputs (Level 3) \| Senior Notes 6.125 % Due 2034
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	$ 0	$ 0

Fair Value Measurements - Fair Value of Life Policy Loans (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of life policy loans	$ 46	$ 50
Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of life policy loans	0	0
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of life policy loans	0	0
Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of life policy loans	$ 46	$ 50

Fair Value Measurements - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivable	$ 79	$ 75
Loss and loss expense reserves	4,284	4,230
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of Level 3 assets measured at fair value	1.00%
Life Policy Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivable	35	37
Deferred Annuities And Structured Settlements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss and loss expense reserves	$ 1,049	$ 1,043

Property Casualty Loss and Loss Expenses - Consolidated Property Casualty Loss and Loss Expense Reserves (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Summary of Consolidated Property Casualty Loss and Loss Expense Reserves [Roll Forward]
Gross loss and loss expense reserves, beginning of period	$ 4,173	$ 4,289	$ 4,169	$ 4,280
Less reinsurance receivable	349	352	356	375
Net loss and loss expense reserves, beginning of period	3,824	3,937	3,813	3,905
Current accident year	675	725	1,209	1,380
Prior accident years	(92)	(85)	(102)	(201)
Total incurred	583	640	1,107	1,179
Current accident year	249	282	370	414
Prior accident years	272	290	664	665
Total paid	521	572	1,034	1,079
Net loss and loss expense reserves, end of period	3,886	4,005	3,886	4,005
Plus reinsurance receivable	333	332	333	332
Gross loss and loss expense reserves, end of period	$ 4,219	$ 4,337	$ 4,219	$ 4,337

Property Casualty Loss and Loss Expenses - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Favorable reserve development on prior accident years	$ 92	$ 85	$ 102	$ 201
Life and Health Loss Reserves
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Reserve for loss and loss expenses	65	59	65	59
Commercial Lines
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Favorable reserve development on prior accident years	66		78
Commercial Lines \| Catastrophe Development
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Favorable reserve development on prior accident years	8	5	15	27
Personal Lines
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Favorable reserve development on prior accident years	26		22
Excess And Surplus Lines Insurance
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Favorable reserve development on prior accident years			$ 2

Reserves in Addition to Account Balance, Based on Expected No-Lapse Guarantee Benefits and Expected Policy Assessments (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	$ 2,345	$ 2,295
Ordinary/Traditional Life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	778	752
Universal Life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	501	483
Deferred Annuities
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	858	850
Structured Settlements
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	192	193
Other
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	$ 16	$ 17

Deferred Acquisition Costs - Deferred Policy Acquisition Costs and Asset Reconciliation (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs asset at beginning of period	$ 491	$ 483	$ 470	$ 477
Capitalized deferred policy acquisition costs	203	192	401	362
Amortized deferred policy acquisition costs	(183)	(181)	(362)	(337)
Amortized shadow deferred policy acquisition costs	35	(10)	37	(18)
Deferred policy acquisition costs asset at end of period	$ 546	$ 484	$ 546	$ 484

Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	$ 1,221		$ 1,221			$ 1,129
Accumulated other comprehensive income, net of tax, end of period	1,221		1,221			1,129
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated unrealized gains, net, on investments available for sale, before tax, beginning of period	2,231	1,717	1,875	1,489
Other comprehensive income before reclassification, before tax	(230)	(47)	164	194
Reclassification adjustment for realized gains, net, included in net income, before tax	(14)	(6)	(52)	(19)
Effect on other comprehensive income, before tax	(244)	(53)	112	175
Accumulated unrealized gains, net, on investments available for sale, before tax, end of period	1,987	1,664	1,987	1,664
Accumulated Other Comprehensive Income Loss Tax [Abstract]
Accumulated unrealized gains, net, on investments available for sale and other invested assets, tax, beginning of period	686	573	686	573
Other comprehensive income before reclassification, tax	(81)	(17)	56	67
Reclassification adjustment for realized gains, net, included in net income, tax	(4)	(2)	(17)	(6)
Effect on other comprehensive income, tax	(85)	(19)	39	61
Accumulated unrealized gains, net, on investments available for sale and other invested assets, tax, end of period	771	592	647	512
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated unrealized gains, net, on investments available for sale and other invested assets, net of tax, beginning of period	1,460	1,125	1,228	977
Other comprehensive income before reclassification , net of tax	(149)	(30)	108	127
Reclassification adjustment for realized gains, net, included in net income, net of tax	(10)	(4)	(35)	(13)
Effect on other comprehensive income, net of tax	(159)	(34)	73	114
Accumulated unrealized gains, net, on investments available for sale and other invested assets, net of tax, end of period	1,301	1,091	1,301	1,091
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Other comprehensive income before reclassification, before tax	0	0	0	0
Accumulated unrealized losses, net, for pension obligations, before Tax, beginning of period	(99)	(86)	(101)	(88)
Reclassification adjustment for amortization of actuarial loss and prior service cost, net, included in net income, before tax	3	1	5	3
Effect on other comprehensive income, before tax	3	1	5	3
Accumulated unrealized losses, net, for pension obligations, before Tax, end of period	(96)	(85)	(96)	(85)
Accumulated Other Comprehensive Income Loss Tax [Abstract]
Other comprehensive income before reclassification, tax	0	0	0	0
Accumulated unrealized losses, net, for pension obligations, tax, beginning of period	(34)	(30)	(35)	(31)
Reclassification adjustment for amortization of actuarial loss and prior service cost, net, included in net income, tax	1	0	2	1
Effect on other comprehensive income, tax	1	0	2	1
Accumulated unrealized losses, net, for pension obligations, tax, end of period	(33)	(30)	(33)	(30)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other comprehensive income before reclassification , net of tax	0	0	0	0
Accumulated unrealized losses, net, for pension obligations, net of tax, beginning of period	(65)	(56)	(66)	(57)
Reclassification adjustment for amortization of actuarial loss and prior service cost,net, included in net income, net of tax	2	1	3	2
Effect on other comprehensive income, net of tax	2	1	3	2
Accumulated unrealized losses, net, for pension obligations, net of tax, end of period	(63)	(55)	(63)	(55)
Accumulated Net Unrealized Gain (Loss) on Deferred Costs, Reserves And Other
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, before tax, beginning of period	(50)	(34)	(50)	(29)
Effect on other comprehensive income, before tax	24	(5)	24	(10)
Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, before tax, end of period	(26)	(39)	(26)	(39)
Accumulated Other Comprehensive Income Loss Tax [Abstract]
Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, tax, beginning of period	(17)	(12)	(17)	(10)
Effect on other comprehensive income, tax	8	(1)	8	(3)
Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, tax, end of period	(9)	(13)	(9)	(13)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, beginning of period, net of tax	(33)	(22)	(33)	(19)
Effect on other comprehensive income, net of tax	16	(4)	16	(7)
Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, end of period, net of tax	(17)	(26)	(17)	(26)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before taxes, beginning of period	2,082	1,597	1,724	1,372
Change in unrealized gains, net, on investments available for sale, before Tax	(244)	(53)	112	175
Change in pension obligations, before tax	3	1	5	3
Change in life deferred acquisition costs, life policy reserves and other, before Tax	24	(5)	24	(10)
Effect on other comprehensive income, before Tax	(217)	(57)	141	168
Accumulated other comprehensive income, before taxes, end of period	1,865	1,540	1,865	1,540
Accumulated Other Comprehensive Income Loss Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	720	550	595	471
Change in unrealized gains, net, on investments available for sale and other invested assets, tax	(85)	(19)	39	61
Change in pension obligations, tax	1	0	2	1
Change in life deferred acquisition costs, life policy reserves and other, tax	8	(1)	8	(3)
Effect on other comprehensive income, tax	(76)	(20)	49	59
Accumulated other comprehensive income, tax, end of period	644	530	644	530
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	1,221	1,010	1,221	1,010	1,362	1,129	1,047	901
Change in unrealized gains, net, on investments available for sale, net of tax	(159)	(34)	73	114
Change in pension obligations, net of tax	2	1	3	2
Change in life deferred acquisition costs, life policy reserves and other, net of tax	16	(4)	16	(7)
Effect on other comprehensive income, net of tax	(141)	(37)	92	109
Accumulated other comprehensive income, net of tax, end of period	$ 1,221	$ 1,010	$ 1,221	$ 1,010	$ 1,362	$ 1,129	$ 1,047	$ 901

Reinsurance - Earned Consolidated Property Casualty Insurance Premiums on Assumed and Ceded Business (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Reinsurance Disclosures [Abstract]
Direct earned premiums	$ 958	$ 868	$ 1,893	$ 1,707
Assumed earned premiums	3	3	5	6
Ceded earned premiums	(51)	(45)	(99)	(89)
Net earned premiums	$ 910	$ 826	$ 1,799	$ 1,624

Reinsurance - Incurred Consolidated Property Casualty Insurance Loss and Loss Expenses on Assumed and Ceded Business (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Net incurred loss and loss expenses	$ 631	$ 687	$ 1,199	$ 1,269
Property, Liability And Casualty Insurance Segment
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct incurred loss and loss expenses	593	647	1,128	1,183
Assumed incurred loss and loss expenses	5	1	7	6
Ceded incurred loss and loss expenses	(15)	(8)	(28)	(10)
Net incurred loss and loss expenses	$ 583	$ 640	$ 1,107	$ 1,179

Reinsurance - Earned Life Insurance Premiums on Ceded Business (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct earned premiums	$ 958	$ 868	$ 1,893	$ 1,707
Assumed earned premiums	3	3	5	6
Ceded earned premiums	(51)	(45)	(99)	(89)
Life Insurance Segment
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct earned premiums	58	64	114	118
Assumed earned premiums	0	0	0	0
Ceded earned premiums	(14)	(13)	(28)	(26)
Net earned premiums	$ 44	$ 51	$ 86	$ 92

Reinsurance - Life Insurance Contract Holders' Benefits Incurred on Ceded Business (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Assumed earned premiums	$ 3	$ 3	$ 5	$ 6
Net incurred loss and loss expenses	631	687	1,199	1,269
Life Insurance Segment
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct policyholders' benefits incurred	62	57	126	110
Assumed policyholders' benefits incurred	0	0	0
Assumed earned premiums	0	0	0	0
Ceded policyholders' benefits incurred	(14)	(10)	(34)	(20)
Net incurred loss and loss expenses	$ 48	$ 47	$ 92	$ 90

Income Taxes - Differences Between 35 Percent Statutory Income Tax Rate and Effective Income Tax Rate (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Tax Disclosure [Abstract]
Tax at statutory rate	$ 52	$ 10	$ 128	$ 49
Increase (decrease) resulting from:
Tax-exempt income from municipal bonds	(9)	(8)	(16)	(17)
Dividend received exclusion	(6)	(6)	(12)	(11)
Other	1	1	1	2
Total provision (benefit) for income taxes	$ 38	$ (3)	$ 101	$ 23
Tax at statutory rate	35.00%	35.00%	35.00%	35.00%
Increase (decrease) resulting from:
Tax-exempt income from municipal bonds	(6.10%)	(27.60%)	(4.40%)	(12.10%)
Dividend received exclusion	(4.20%)	(20.70%)	(3.30%)	(7.80%)
Other	1.00%	3.00%	0.40%	1.20%
Provision (benefit) for income taxes	25.70%	(10.30%)	27.70%	16.30%

Net Income Per Common Share - Calculations for Basic and Diluted Earnings Per Share (Detail) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Numerator:
Net income-basic and diluted	$ 110	$ 32	$ 264	$ 118
Denominator:
Weighted-average common shares outstanding (in shares)	163,512	162,425	163,323	162,351
Adjusted diluted weighted-average shares (in shares)	165,442	163,514	165,151	163,328
Earnings per share:
Basic (in USD per share)	$ 0.67	$ 0.20	$ 1.62	$ 0.73
Diluted (in USD per share)	$ 0.66	$ 0.20	$ 1.60	$ 0.72
Number of anti-dilutive stock-based awards (in shares)	340	6,059	393	6,072
Nonvested shares
Denominator:
Effect of stock-based awards (in shares)	1,239	419	1,098	375
Stock Options
Denominator:
Effect of stock-based awards (in shares)	691	670	730	602

Employee Retirement Benefits - Components of Net Periodic Costs for Qualified and Supplemental Pension Plans (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Compensation and Retirement Disclosure [Abstract]
Service cost	$ 3	$ 3	$ 6	$ 6
Interest cost	3	4	6	7
Expected return on plan assets	(4)	(4)	(8)	(8)
Amortization of actuarial loss and prior service cost	3	1	5	3
Net periodic benefit cost	$ 5	$ 4	$ 9	$ 8

Employee Retirement Benefits - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Matching contributions for 401(k) plan and Top Hat savings plan	$ 2		$ 3	$ 5	$ 5
Pension Contributions		15
Qualified Pension Plans [Member] \| Future Period [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected contribution by employer for the remainder of the year	$ 0		$ 0	$ 0	$ 0

Segment Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenues	$ 1,104	$ 1,020	$ 2,207	$ 2,006
Net Investment Income	131	132	259	263
Realized gains on investments	14	6	55	19
Income (loss) before income taxes	148	29	365	141
Identifiable assets	17,034		17,034		16,548
Property Casualty Insurance Segment
Segment Reporting Information [Line Items]
Identifiable assets	2,489		2,489		2,395
Commercial Lines
Segment Reporting Information [Line Items]
Revenues	646	591	1,277	1,160
Income (loss) before income taxes	34	(20)	92	14
Commercial Lines \| Commercial Casualty Segment
Segment Reporting Information [Line Items]
Revenues	211	191	415	372
Commercial Lines \| Commercial Property Segment
Segment Reporting Information [Line Items]
Revenues	152	134	299	265
Commercial Lines \| Commercial Auto Segment
Segment Reporting Information [Line Items]
Revenues	117	106	231	207
Commercial Lines \| Workers' Compensation
Segment Reporting Information [Line Items]
Revenues	87	85	175	166
Commercial Lines \| Specialty Packages
Segment Reporting Information [Line Items]
Revenues	37	37	76	75
Commercial Lines \| Surety and Executive Risk
Segment Reporting Information [Line Items]
Revenues	30	27	59	54
Commercial Lines \| Machinery and Equipment
Segment Reporting Information [Line Items]
Revenues	11	10	21	19
Commercial Lines \| Commercial Lines Insurance Premiums
Segment Reporting Information [Line Items]
Revenues	645	590	1,276	1,158
Commercial Lines \| Other Fee Revenue
Segment Reporting Information [Line Items]
Revenues	1	1	1	2
Personal Lines
Segment Reporting Information [Line Items]
Revenues	238	215	469	424
Income (loss) before income taxes	(1)	(55)	19	(77)
Personal Lines \| Personal Auto
Segment Reporting Information [Line Items]
Revenues	109	100	216	198
Personal Lines \| Home Owner Segment
Segment Reporting Information [Line Items]
Revenues	99	87	195	171
Personal Lines \| Other Personal Lines
Segment Reporting Information [Line Items]
Revenues	29	27	57	54
Personal Lines \| Commercial Lines Insurance Premiums
Segment Reporting Information [Line Items]
Revenues	237	214	468	423
Personal Lines \| Other Fee Revenue
Segment Reporting Information [Line Items]
Revenues	1	1	1	1
Excess And Surplus Lines Insurance
Segment Reporting Information [Line Items]
Revenues	28	22	55	43
Income (loss) before income taxes	1	(2)	1	(5)
Life Insurance Segment
Segment Reporting Information [Line Items]
Revenues	45	51	88	92
Income (loss) before income taxes	3	2	10	(1)
Identifiable assets	1,254		1,254		1,201
Life Insurance Segment \| Life Insurance Excluding Account Investment Fees
Segment Reporting Information [Line Items]
Revenues	44	51	86	92
Life Insurance Segment \| Seperate Account Investment Management Fees
Segment Reporting Information [Line Items]
Revenues	1	0	2	0
Investments Segment
Segment Reporting Information [Line Items]
Revenues	145	138	314	282
Income (loss) before income taxes	127	118	275	241
Identifiable assets	12,983		12,983		12,599
Investments Segment \| Investment Income, Net
Segment Reporting Information [Line Items]
Revenues	131	132
Net Investment Income				263
Investments Segment \| Realized Investment Gains, Net
Segment Reporting Information [Line Items]
Revenues	14	6		19
Other
Segment Reporting Information [Line Items]
Revenues	2	3	4	5
Income (loss) before income taxes	(16)	(14)	(32)	(31)
Identifiable assets	$ 308		$ 308		$ 353

Segment Information - Narrative (Details)	6 Months Ended
Segment Information - Narrative (Details)	Jun. 30, 2013 segment industry
Segment Reporting [Abstract]
Number of Industries Operating In	2
Number of Reportable Segments	5

Fair Value Measurements - Fair Value Hierarchy for Assets Measured at Fair Value on Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	$ 8,992	$ 9,093
Equity securities, at fair value	3,875	3,373
Separate accounts	713	734
Fair value of asset	13,571	13,164
Top Hat Savings Plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	11	9
Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	8,992	9,093
Debt Securities \| States, Municipalities And Political Subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	3,188	3,289
Debt Securities \| Convertibles And Bonds With Warrants Attached
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	16	31
Debt Securities \| United States Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	7	8
Debt Securities \| Government-Sponsored Enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	195	164
Debt Securities \| Foreign Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	10	3
Debt Securities \| Commercial Mortgage Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	60	28
Debt Securities \| Corporate Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	5,516	5,570
Equity Securities \| Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	3,761	3,238
Equity Securities \| Preferred Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	114	135
Taxable Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Separate accounts	693	689
Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of asset	3,779	3,255
Quoted prices in active markets for identical assets (Level 1) \| Top Hat Savings Plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	11	9
Quoted prices in active markets for identical assets (Level 1) \| Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	7	8
Quoted prices in active markets for identical assets (Level 1) \| Debt Securities \| States, Municipalities And Political Subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) \| Debt Securities \| Convertibles And Bonds With Warrants Attached
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) \| Debt Securities \| United States Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	7	8
Quoted prices in active markets for identical assets (Level 1) \| Debt Securities \| Government-Sponsored Enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) \| Debt Securities \| Foreign Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) \| Debt Securities \| Commercial Mortgage Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) \| Debt Securities \| Corporate Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) \| Equity Securities \| Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	3,761	3,238
Quoted prices in active markets for identical assets (Level 1) \| Equity Securities \| Preferred Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) \| Taxable Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Separate accounts	0	0
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of asset	9,786	9,904
Significant other observable inputs (Level 2) \| Top Hat Savings Plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Significant other observable inputs (Level 2) \| Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	8,981	9,081
Significant other observable inputs (Level 2) \| Debt Securities \| States, Municipalities And Political Subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	3,187	3,288
Significant other observable inputs (Level 2) \| Debt Securities \| Convertibles And Bonds With Warrants Attached
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	16	31
Significant other observable inputs (Level 2) \| Debt Securities \| United States Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant other observable inputs (Level 2) \| Debt Securities \| Government-Sponsored Enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	195	164
Significant other observable inputs (Level 2) \| Debt Securities \| Foreign Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	10	3
Significant other observable inputs (Level 2) \| Debt Securities \| Commercial Mortgage Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	60	28
Significant other observable inputs (Level 2) \| Debt Securities \| Corporate Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	5,513	5,567
Significant other observable inputs (Level 2) \| Equity Securities \| Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	0	0
Significant other observable inputs (Level 2) \| Equity Securities \| Preferred Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	112	134
Significant other observable inputs (Level 2) \| Taxable Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Separate accounts	693	689
Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of asset	6	5
Significant unobservable inputs (Level 3) \| Top Hat Savings Plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	0	0
Significant unobservable inputs (Level 3) \| Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	4	4
Significant unobservable inputs (Level 3) \| Debt Securities \| States, Municipalities And Political Subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	1	1
Significant unobservable inputs (Level 3) \| Debt Securities \| Convertibles And Bonds With Warrants Attached
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant unobservable inputs (Level 3) \| Debt Securities \| United States Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant unobservable inputs (Level 3) \| Debt Securities \| Government-Sponsored Enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant unobservable inputs (Level 3) \| Debt Securities \| Foreign Government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant unobservable inputs (Level 3) \| Debt Securities \| Commercial Mortgage Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant unobservable inputs (Level 3) \| Debt Securities \| Corporate Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	3	3
Significant unobservable inputs (Level 3) \| Equity Securities \| Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	0	0
Significant unobservable inputs (Level 3) \| Equity Securities \| Preferred Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	2	1
Significant unobservable inputs (Level 3) \| Taxable Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Separate accounts	$ 0	$ 0

Fair Value Measurements - Fair Values of Deferred Annuities, Structured Settlements and Other Items (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	$ 1,114	$ 1,138
Deferred Annuities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	887	898
Structured Settlements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	227	240
Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	0	0
Quoted prices in active markets for identical assets (Level 1) \| Deferred Annuities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	0	0
Quoted prices in active markets for identical assets (Level 1) \| Structured Settlements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	0	0
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	227	240
Significant other observable inputs (Level 2) \| Deferred Annuities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	0	0
Significant other observable inputs (Level 2) \| Structured Settlements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	227	240
Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	887	898
Significant unobservable inputs (Level 3) \| Deferred Annuities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	887	898
Significant unobservable inputs (Level 3) \| Structured Settlements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	$ 0	$ 0

Income Taxes (Narrative) (Details)	3 Months Ended		6 Months Ended
Income Taxes (Narrative) (Details)	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Tax Disclosure [Abstract]
Tax at statutory rate, percentage	35.00%	35.00%	35.00%	35.00%

Commitments and Contingent Liabilities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Loss Contingencies [Line Items]
Estimate for which the risk of loss is more than remote but not probable	$ 2