CNA Financial (CNA) 10-Q 29 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document	9 Months Ended
	Sep. 30, 2013	Oct. 25, 2013
Document and Entity Information [Abstract]
Entity Registrant Name	CNA FINANCIAL CORP
Entity Central Index Key	21175
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	30-Sep-13
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		269,702,799

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues
Net earned premiums	$1,825	$1,781	$5,389	$5,098
Net investment income	597	601	1,808	1,719
Net realized investment gains (losses):
Other-than-temporary impairment losses	-15	-62	-49	-89
Portion of other-than-temporary impairments recognized in Other comprehensive income (loss)	-2	-2	-2	-25
Net other-than-temporary impairment losses recognized in earnings	-17	-64	-51	-114
Other net realized investment gains (losses)	21	72	69	180
Net realized investment gains (losses)	4	8	18	66
Other revenues	78	76	285	230
Total revenues	2,504	2,466	7,500	7,113
Claims, Benefits and Expenses
Insurance claims and policyholders’ benefits	1,414	1,435	4,364	4,164
Amortization of deferred acquisition costs	341	333	1,004	937
Other operating expenses	332	341	993	976
Interest	42	43	125	128
Total claims, benefits and expenses	2,129	2,152	6,486	6,205
Income (loss) before income tax	375	314	1,014	908
Income tax (expense) benefit	-103	-93	-298	-271
Net income (loss)	$272	$221	$716	$637
Basic earnings (loss) per share	$1.01	$0.82	$2.66	$2.37
Diluted earnings (loss) per share	$1.01	$0.82	$2.65	$2.36
Dividends per share	$0.20	$0.15	$0.60	$0.45
Weighted Average Outstanding Common Stock and Common Stock Equivalents
Basic	269.7	269.4	269.6	269.4
Diluted	270.2	269.8	270.1	269.8

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Changes in:
Net unrealized gains (losses) on investments with other-than-temporary impairments	($3)	$36	$3	$73
Net unrealized gains (losses) on other investments	-70	191	-717	528
Net unrealized gains (losses) on investments	-73	227	-714	601
Foreign currency translation adjustment	56	33	-18	37
Pension and postretirement benefits	4	3	14	12
Other comprehensive income (loss), net of tax	-13	263	-718	650
Net income (loss)	272	221	716	637
Total comprehensive income (loss)	$259	$484	($2)	$1,287

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Assets
Fixed maturity securities at fair value (amortized cost of $39,129 and $38,170)	$41,274	$42,633
Equity securities at fair value (cost of $189 and $228)	199	249
Limited partnership investments	2,790	2,462
Other invested assets	55	59
Mortgage loans	440	401
Short term investments	1,475	1,832
Total investments	46,233	47,636
Cash	185	156
Reinsurance receivables (less allowance for uncollectible receivables of $72 and $73)	5,731	6,158
Insurance receivables (less allowance for uncollectible receivables of $90 and $101)	1,993	1,882
Accrued investment income	482	434
Deferred acquisition costs	642	598
Deferred income taxes	331	93
Property and equipment at cost (less accumulated depreciation of $358 and $404)	334	326
Goodwill	154	154
Other assets (includes $0 and $4 due from Loews Corporation)	889	773
Separate account business	213	312
Total assets	57,187	58,522
Liabilities
Claim and claim adjustment expenses	23,962	24,763
Unearned premiums	3,820	3,610
Future policy benefits	10,681	11,475
Policyholders’ funds	127	157
Short term debt		13
Long term debt	2,559	2,557
Other liabilities (includes $129 and $0 due to Loews Corporation)	3,672	3,321
Separate account business	213	312
Total liabilities	45,034	46,208
Commitments and contingencies (Notes C, G and J)
Stockholders' Equity
Common stock ($2.50 par value; 500,000,000 shares authorized; 273,040,243 shares issued; 269,701,999 and 269,399,390 shares outstanding)	683	683
Additional paid-in capital	2,142	2,146
Retained earnings	9,328	8,774
Accumulated other comprehensive income (loss)	113	831
Treasury stock (3,338,244 and 3,640,853 shares), at cost	-91	-99
Notes receivable for the issuance of common stock	-22	-21
Total stockholders’ equity	12,153	12,314
Total liabilities and stockholders' equity	$57,187	$58,522

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheet (Unaudited) Parentheticals (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Balance Sheets Parenthetical [Abstract]
Fixed maturities securities at amortized cost	$39,129	$38,170
Equity securities at cost	189	228
Allowance for uncollectible reinsurance receivables	72	73
Allowance for uncollectible insurance receivables	90	101
Accumulated depreciation on property and equipment	358	404
Other assets receivable from Loews Corporation		4
Other liabilities payable to Loews Corporation	$129
Common stock, par value	$2.50	$2.50
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	273,040,243	273,040,243
Common stock, shares outstanding	269,701,999	269,399,390
Treasury stock, shares	3,338,244	3,640,853

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash Flows from Operating Activities
Net income (loss)	$716	$637
Adjustments to reconcile net income (loss) to net cash flows provided (used) by operating activities:
(Gain) loss on disposal of property and equipment		1
Deferred income tax expense (benefit)	141	95
Trading portfolio activity	2	-13
Net realized investment (gains) losses	-18	-66
Equity method investees	-230	-68
Amortization of investments	-20	-43
Depreciation and amortization	80	83
Changes in:
Receivables, net	316	348
Accrued investment income	-48	-46
Deferred acquisition costs	-23	-27
Insurance reserves	-166	-53
Other assets	-62	90
Other liabilities	233	47
Other, net		8
Total adjustments	205	356
Net cash flows provided (used) by operating activities	921	993
Dispositions:
Fixed maturity securities - sales	4,830	4,761
Fixed maturity securities - maturities, calls and redemptions	2,496	2,655
Equity securities	82	72
Limited partnerships	91	153
Mortgage loans	20	6
Purchases:
Fixed maturity securities	-8,205	-7,369
Equity securities	-61	-30
Limited partnerships	-163	-119
Mortgage loans	-59	-129
Change in other investments	-19	1
Change in short term investments	357	-505
Purchase of Hardy		-197
Purchases of property and equipment	-67	-60
Other, net	9	14
Net cash flows provided (used) by investing activities	-689	-747
Cash Flows from Financing Activities
Dividends paid to common stockholders	-162	-122
Repayment of debt	-13	-70
Stock options exercised	1	1
Other, net	-26	-4
Net cash flows provided (used) by financing activities	-200	-195
Effect of foreign exchange rate changes on cash	-3	3
Net change in cash	29	54
Cash, beginning of year	156	75
Cash, end of period	$185	$129

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (USD $)	Total	Common stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss) [Member]	Treasury stock [Member]	Notes receivable for the issuance of common stock [Member]
In Millions, unless otherwise specified
Balance at Dec. 31, 2011		$683	$2,141	$8,308	$480	($102)	($22)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	637			637
Other comprehensive income (loss)	650				650
Dividends paid to common stockholders				-122
Stock-based compensation			3			3
(Increase) decrease in notes receivable from the issuance of common stock							1
Balance at Sep. 30, 2012	12,660	683	2,144	8,823	1,130	-99	-21
Balance at Dec. 31, 2012	12,314	683	2,146	8,774	831	-99	-21
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	716			716
Other comprehensive income (loss)	-718				-718
Dividends paid to common stockholders				-162
Stock-based compensation			-4			8
(Increase) decrease in notes receivable from the issuance of common stock							-1
Balance at Sep. 30, 2013	$12,153	$683	$2,142	$9,328	$113	($91)	($22)

General

General	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	Note A. General
	Basis of Presentation
	The Condensed Consolidated Financial Statements (Unaudited) include the accounts of CNA Financial Corporation (CNAF) and its subsidiaries. Collectively, CNAF and its subsidiaries are referred to as CNA or the Company. The Company acquired Hardy Underwriting Bermuda Limited and its subsidiaries on July 2, 2012. Loews Corporation (Loews) owned approximately 90% of the outstanding common stock of CNAF as of September 30, 2013.
	The accompanying Condensed Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). Certain financial information that is normally included in annual financial statements, including certain financial statement notes, prepared in accordance with GAAP, is not required for interim reporting purposes and has been condensed or omitted. These statements should be read in conjunction with the Consolidated Financial Statements and notes thereto included in CNAF's Annual Report on Form 10-K filed with the Securities and Exchange Commission for the year ended December 31, 2012, including the summary of significant accounting policies in Note A. The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the Condensed Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting periods. Actual results may differ from those estimates.
	The interim financial data as of September 30, 2013 and for the three and nine months ended September 30, 2013 and 2012 is unaudited. However, in the opinion of management, the interim data includes all adjustments, consisting of normal recurring accruals, necessary for a fair statement of the Company's results for the interim periods. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the full year. Intercompany amounts have been eliminated.

Earnings_loss_per_share

Earnings (loss) per share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]
Earnings Per Share	Note B. Earnings Per Share
	Earnings per share is based on the weighted average number of outstanding common shares. Basic earnings (loss) per share excludes the impact of dilutive securities and is computed by dividing Net income (loss) by the weighted average number of common shares outstanding for the period. Diluted earnings (loss) per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock.
	For the three and nine months ended September 30, 2013, approximately 515 thousand and 501 thousand potential shares attributable to exercises under stock-based employee compensation plans were included in the calculation of diluted earnings per share. For those same periods, approximately 110 thousand and 115 thousand potential shares attributable to exercises under stock-based employee compensation plans were not included in the calculation of diluted earnings per share because the effect would have been antidilutive.
	For the three and nine months ended September 30, 2012, approximately 450 thousand and 400 thousand potential shares attributable to exercises under stock-based employee compensation plans were included in the calculation of diluted earnings per share. For those same periods, approximately 693 thousand and 740 thousand potential shares attributable to exercises under stock-based employee compensation plans were not included in the calculation of diluted earnings per share because the effect would have been antidilutive.

Investments

Investments	9 Months Ended
	Sep. 30, 2013
Investments [Abstract]
Investments	Note C. Investments
	The significant components of net investment income are presented in the following table.
	Net Investment Income
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Fixed maturity securities	$	504		$	507		$	1,501		$	1,528
	Short term investments	1			2			3			5
	Limited partnership investments	93			89			303			184
	Equity securities	3			4			9			10
	Mortgage loans	6			5			17			13
	Trading portfolio (a)	3			7			13			18
	Other	1			—			2			3
	Gross investment income	611			614			1,848			1,761
	Investment expense	(14		)	(13		)	(40		)	(42		)
	Net investment income	$	597		$	601		$	1,808		$	1,719
	___________________
	(a)	There were no net unrealized gains (losses) related to changes in fair value of trading securities still held included in net investment income for the three or nine months ended September 30, 2013 or 2012.
	Net realized investment gains (losses) are presented in the following table.
	Net Realized Investment Gains (Losses)
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Net realized investment gains (losses):
	Fixed maturity securities:
	Gross realized gains	$	51		$	75		$	132		$	193
	Gross realized losses	(44		)	(49		)	(98		)	(120		)
	Net realized investment gains (losses) on fixed maturity securities	7			26			34			73
	Equity securities:
	Gross realized gains	3			5			10			10
	Gross realized losses	(5		)	(20		)	(27		)	(24		)
	Net realized investment gains (losses) on equity securities	(2		)	(15		)	(17		)	(14		)
	Derivatives	(1		)	(1		)	(4		)	(1		)
	Short term investments and other	—			(2		)	5			8
	Net realized investment gains (losses)	$	4		$	8		$	18		$	66
	The components of net other-than-temporary impairment (OTTI) losses recognized in earnings by asset type are summarized in the following table.
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	9		$	7		$	17		$	23
	States, municipalities and political subdivisions	—			17			—			17
	Asset-backed:
	Residential mortgage-backed	2			20			5			49
	Other asset-backed	1			—			2			—
	Total asset-backed	3			20			7			49
	U.S. Treasury and obligations of government-sponsored enterprises	—			—			—			1
	Total fixed maturity securities available-for-sale	12			44			24			90
	Equity securities available-for-sale:
	Common stock	3			1			5			5
	Preferred stock	2			19			22			19
	Total equity securities available-for-sale	5			20			27			24
	Net OTTI losses recognized in earnings	$	17		$	64		$	51		$	114
	The following tables provide a summary of fixed maturity and equity securities.
	Summary of Fixed Maturity and Equity Securities
	September 30, 2013	Cost or			Gross			Gross			Estimated			Unrealized
		Amortized			Unrealized			Unrealized			Fair			OTTI
	(In millions)	Cost			Gains			Losses			Value			Losses (Gains)
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	19,616		$	1,695		$	151		$	21,160		$	—
	States, municipalities and political subdivisions	11,000			672			233			11,439			—
	Asset-backed:
	Residential mortgage-backed	4,779			141			101			4,819			(33		)
	Commercial mortgage-backed	1,942			99			24			2,017			(3		)
	Other asset-backed	942			16			2			956			—
	Total asset-backed	7,663			256			127			7,792			(36		)
	U.S. Treasury and obligations of government-sponsored enterprises	166			8			1			173			—
Foreign government	547			17			3			561			—
Redeemable preferred stock	94			12			—			106			—
Total fixed maturity securities available-for-sale	39,086			2,660			515			41,231			$	(36	)
Total fixed maturity securities trading	43			—			—			43
Equity securities available-for-sale:
Common stock	41			12			—			53
Preferred stock	148			1			3			146
Total equity securities available-for-sale	189			13			3			199
Total	$	39,318		$	2,673		$	518		$	41,473
December 31, 2012	Cost or			Gross			Gross			Estimated			Unrealized
	Amortized			Unrealized			Unrealized			Fair			OTTI
(In millions)	Cost			Gains			Losses			Value			Losses (Gains)
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	19,530		$	2,698		$	21		$	22,207		$	—
States, municipalities and political subdivisions	9,372			1,455			44			10,783			—
Asset-backed:
Residential mortgage-backed	5,745			246			71			5,920			(28		)
Commercial mortgage-backed	1,692			147			17			1,822			(3		)
Other asset-backed	929			23			—			952			—
Total asset-backed	8,366			416			88			8,694			(31		)
U.S. Treasury and obligations of government-sponsored enterprises	172			11			1			182			—
Foreign government	588			25			—			613			—
Redeemable preferred stock	113			13			1			125			—
Total fixed maturity securities available-for-sale	38,141			4,618			155			42,604			$	(31	)
Total fixed maturity securities trading	29			—			—			29
Equity securities available-for-sale:
Common stock	38			14			—			52
Preferred stock	190			7			—			197
Total equity securities available-for-sale	228			21			—			249
Total	$	38,398		$	4,639		$	155		$	42,882
The net unrealized gains on investments included in the tables above are recorded as a component of Accumulated other comprehensive income (AOCI). When presented in AOCI, these amounts are net of tax and any required Shadow Adjustments. At September 30, 2013 and December 31, 2012, the net unrealized gains on investments included in AOCI were net of after-tax Shadow Adjustments of $723 million and $1,511 million. To the extent that unrealized gains on fixed income securities supporting certain products within the Life & Group Non-Core segment would result in a premium deficiency if realized, a related decrease in Deferred acquisition costs and/or increase in Insurance reserves are recorded, net of tax, as a reduction of net unrealized gains through Other comprehensive income (loss) (Shadow Adjustments).
The following tables summarize the estimated fair value and gross unrealized losses of available-for-sale fixed maturity and equity securities in a gross unrealized loss position by the length of time in which the securities have continuously been in that position.
Securities in a Gross Unrealized Loss Position
	Less than 12 Months						12 Months or Longer						Total
September 30, 2013	Estimated			Gross			Estimated			Gross			Estimated			Gross
	Fair Value			Unrealized			Fair Value			Unrealized			Fair Value			Unrealized
(In millions)				Losses						Losses						Losses
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	3,521		$	146		$	45		$	5		$	3,566		$	151
States, municipalities and political subdivisions	2,413			179			122			54			2,535			233
Asset-backed:
Residential mortgage-backed	1,289			40			287			61			1,576			101
Commercial mortgage-backed	449			20			79			4			528			24
Other asset-backed	207			2			—			—			207			2
Total asset-backed	1,945			62			366			65			2,311			127
U.S. Treasury and obligations of government-sponsored enterprises	21			1			—			—			21			1
Foreign government	76			3			—			—			76			3
Total fixed maturity securities available-for-sale	7,976			391			533			124			8,509			515
Equity securities available-for-sale:
Preferred stock	86			3			—			—			86			3
Total	$	8,062		$	394		$	533		$	124		$	8,595		$	518
	Less than 12 Months						12 Months or Longer						Total
December 31, 2012	Estimated			Gross			Estimated			Gross			Estimated			Gross
	Fair Value			Unrealized			Fair Value			Unrealized			Fair Value			Unrealized
(In millions)				Losses						Losses						Losses
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	846		$	13		$	108		$	8		$	954		$	21
States, municipalities and political subdivisions	254			5			165			39			419			44
Asset-backed:
Residential mortgage-backed	583			5			452			66			1,035			71
Commercial mortgage-backed	85			2			141			15			226			17
Total asset-backed	668			7			593			81			1,261			88
U.S. Treasury and obligations of government-sponsored enterprises	23			1			—			—			23			1
Redeemable preferred stock	28			1			—			—			28			1
Total	$	1,819		$	27		$	866		$	128		$	2,685		$	155
The amount of pretax net realized gains on available-for-sale securities reclassified out of AOCI into earnings was $3 million and $15 million for the three and nine months ended September 30, 2013 and $12 million and $59 million for the three and nine months ended September 30, 2012.
Based on current facts and circumstances, the Company believes the unrealized losses presented in the September 30, 2013 Securities in a Gross Unrealized Loss Position table above, are primarily attributable to broader economic conditions, changes in interest rates and credit spreads, market illiquidity and other market factors, but are not indicative of the ultimate collectibility of the current amortized cost of the securities. The investments with longer duration, primarily included within the states, municipalities and political subdivision asset category, were more significantly impacted by changes in market interest rates. The Company has no current intent to sell these securities, nor is it more likely than not that it will be required to sell prior to recovery of amortized cost; accordingly, the Company has determined that there are no additional OTTI losses to be recorded at September 30, 2013.
The following table summarizes the activity for the three and nine months ended September 30, 2013 and 2012 related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held at September 30, 2013 and 2012 for which a portion of an OTTI loss was recognized in Other comprehensive income (loss).
Periods ended September 30	Three Months						Nine Months
(In millions)	2013			2012			2013			2012
Beginning balance of credit losses on fixed maturity securities	$	89		$	99		$	95		$	92
Additional credit losses for securities for which an OTTI loss was previously recognized	1			2			2			23
Credit losses for securities for which an OTTI loss was not previously recognized	—			—			—			2
Reductions for securities sold during the period	(7		)	(3		)	(14		)	(11		)
Reductions for securities the Company intends to sell or more likely than not will be required to sell	—			—			—			(8		)
Ending balance of credit losses on fixed maturity securities	$	83		$	98		$	83		$	98
Contractual Maturity
The following table summarizes available-for-sale fixed maturity securities by contractual maturity at September 30, 2013 and December 31, 2012. Actual maturities may differ from contractual maturities because certain securities may be called or prepaid with or without call or prepayment penalties. Securities not due at a single date are allocated based on weighted average life.
Contractual Maturity
	September 30, 2013						December 31, 2012
(In millions)	Cost or			Estimated			Cost or			Estimated
	Amortized			Fair			Amortized			Fair
	Cost			Value			Cost			Value
Due in one year or less	$	2,475		$	2,516		$	1,648		$	1,665
Due after one year through five years	10,687			11,304			13,603			14,442
Due after five years through ten years	10,586			10,901			8,726			9,555
Due after ten years	15,338			16,510			14,164			16,942
Total	$	39,086		$	41,231		$	38,141		$	42,604
Investment Commitments
As of September 30, 2013, the Company had committed approximately $405 million to future capital calls from various third-party limited partnership investments in exchange for an ownership interest in the related partnerships.
The Company invests in various privately placed debt securities, including bank loans, as part of its overall investment strategy and has committed to additional future purchases, sales and funding. As of September 30, 2013, the Company had commitments to purchase or fund additional amounts of $172 million and sell $143 million under the terms of such securities.

Derivative_Financial_Instrumen

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2013
Summary of Derivative Instruments [Abstract]
Derivative Financial Instruments	Note D. Derivative Financial Instruments
	Gross estimated fair values of derivative positions are presented in Other invested assets and Other liabilities on the Condensed Consolidated Balance Sheets. There would be no significant difference in the balance included in such accounts if the estimated fair values were presented net for the periods ended September 30, 2013 and December 31, 2012. The contractual or notional amounts for derivatives are used to calculate the exchange of contractual payments under the agreements and may not be representative of the potential for gain or loss on these instruments.
	Derivative Financial Instruments
	September 30, 2013	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Credit default swaps - purchased protection	$	20	$	—	$	—
	Currency forwards	27		—		(1		)
	Equity warrants	5		—		—
	Total without hedge designation	52		—		(1		)
	Trading activities
	Futures sold, not yet purchased	17		—		—
	Total	$	69	$	—	$	(1	)
	December 31, 2012	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Credit default swaps - purchased protection	$	20	$	—	$	(1	)
	Currency forwards	59		—		(2		)
	Equity warrants	5		—		—
	Total	$	84	$	—	$	(3	)
	During the three and nine months ended September 30, 2013, new derivative transactions entered into totaled $224 million and $2,271 million in notional value while derivative termination activity totaled $221 million and $2,286 million. This activity was attributable to forward commitments for mortgage-backed securities, interest rate futures and foreign currency forwards. During the three and nine months ended September 30, 2012, new derivative transactions entered into totaled $472 million and $1,251 million in notional value while derivative termination activity totaled $488 million and $1,200 million. This activity was primarily attributable to interest rate futures, forward commitments for mortgage-backed securities and foreign currency forwards.

Fair_Value

Fair Value	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]
Fair Value	Note E. Fair Value
	Fair value is the price that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The following fair value hierarchy is used in selecting inputs, with the highest priority given to Level 1, as these are the most transparent or reliable.
	Level 1 - Quoted prices for identical instruments in active markets.
	Level 2 - Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs are observable in active markets.
	Level 3 - Valuations derived from valuation techniques in which one or more significant inputs are not observable.
	Prices may fall within Level 1, 2 or 3 depending upon the methodologies and inputs used to estimate fair value for each specific security. Prices are determined by a dedicated group who ultimately report to the Company's Chief Financial Officer. This group is responsible for valuation policies and procedures. In general the Company seeks to price securities using third-party pricing services. Securities not priced by pricing services are submitted to independent brokers for valuation and, if those are not available, internally developed pricing models are used to value assets using methodologies and inputs the Company believes market participants would use to value the assets. Prices obtained from third-party pricing services or brokers are not adjusted by the Company.
	The Company performs control procedures over information obtained from pricing services and brokers to ensure prices received represent a reasonable estimate of fair value and to confirm representations regarding whether inputs are observable or unobservable. Procedures include i) the review of pricing service or broker pricing methodologies, ii) back-testing, where past fair value estimates are compared to actual transactions executed in the market on similar dates, iii) exception reporting, where changes in price, period-over-period, are reviewed and challenged with the pricing service or broker based on exception criteria, iv) deep dives, where the Company independently validates detailed information regarding inputs and assumptions for individual securities and v) pricing validation, where prices received are compared to prices independently estimated by the Company.
	Assets and Liabilities Measured at Fair Value
	Assets and liabilities measured at fair value on a recurring basis are summarized below.
	September 30, 2013									Total
										Assets/(Liabilities)
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	27	$	20,945		$	211		$	21,183
	States, municipalities and political subdivisions	—		11,364			95			11,459
	Asset-backed:
	Residential mortgage-backed	—		4,449			370			4,819
	Commercial mortgage-backed	—		1,860			157			2,017
	Other asset-backed	—		523			433			956
	Total asset-backed	—		6,832			960			7,792
	U.S. Treasury and obligations of government-sponsored enterprises	144		29			—			173
	Foreign government	81		480			—			561
	Redeemable preferred stock	48		58			—			106
	Total fixed maturity securities	300		39,708			1,266			41,274
	Equity securities	135		51			13			199
	Other invested assets	—		55			—			55
	Short term investments	992		430			—			1,422
	Life settlement contracts, included in Other assets	—		—			90			90
	Separate account business	12		199			2			213
	Total assets	$	1,439	$	40,443		$	1,371		$	43,253
	Liabilities
	Derivative financial instruments, included in Other liabilities	$	—	$	(1	)	$	—		$	(1	)
	Total liabilities	$	—	$	(1	)	$	—		$	(1	)
	December 31, 2012									Total
										Assets/(Liabilities)
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	6	$	22,011		$	219		$	22,236
	States, municipalities and political subdivisions	—		10,687			96			10,783
	Asset-backed:
	Residential mortgage-backed	—		5,507			413			5,920
	Commercial mortgage-backed	—		1,693			129			1,822
	Other asset-backed	—		584			368			952
	Total asset-backed	—		7,784			910			8,694
	U.S. Treasury and obligations of government-sponsored enterprises	158		24			—			182
	Foreign government	140		473			—			613
	Redeemable preferred stock	40		59			26			125
	Total fixed maturity securities	344		41,038			1,251			42,633
	Equity securities	117		98			34			249
	Other invested assets	—		58			1			59
	Short term investments	987		799			6			1,792
	Life settlement contracts, included in Other assets	—		—			100			100
	Separate account business	4		306			2			312
	Total assets	$	1,452	$	42,299		$	1,394		$	45,145
	Liabilities
	Derivative financial instruments, included in Other liabilities	$	—	$	(2	)	$	(1	)	$	(3	)
	Total liabilities	$	—	$	(2	)	$	(1	)	$	(3	)
	The tables below present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended September 30, 2013 and 2012.
	Level 3	Balance at		Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at		Unrealized gains (losses) on Level 3 assets and liabilities held at September 30, 2013 recognized in net income (loss)*
	(In millions)	July 1,																	Level 3		of Level 3			September 30,
		2013																						2013
	Fixed maturity securities:
Corporate and other bonds	$	202	$	1		$	—		$	6		$	(6	)	$	(8	)	$	17	$	(1	)	$	211	$	—
States, municipalities and political subdivisions	140		—			(3		)	—			—			(15		)	—		(27		)	95		—
Asset-backed:
Residential mortgage-backed	428		—			(20		)	5			—			(21		)	—		(22		)	370		(1		)
Commercial mortgage-backed	165		(1		)	(2		)	10			—			(1		)	—		(14		)	157		—
Other asset-backed	387		—			1			56			—			(6		)	—		(5		)	433		(1		)
Total asset-backed	980		(1		)	(21		)	71			—			(28		)	—		(41		)	960		(2		)
Redeemable preferred stock	25		(1		)	1			—			—			(25		)	—		—			—		—
Total fixed maturity securities	1,347		(1		)	(23		)	77			(6		)	(76		)	17		(69		)	1,266		(2		)
Equity securities	13		(2		)	2			—			—			—			—		—			13		(2		)
Life settlement contracts	91		3			—			—			—			(4		)	—		—			90		—
Separate account business	2		—			—			—			—			—			—		—			2		—
Total	$	1,453	$	—		$	(21	)	$	77		$	(6	)	$	(80	)	$	17	$	(69	)	$	1,371	$	(4	)
Level 3	Balance at		Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at		Unrealized gains (losses) on Level 3 assets and liabilities held at September 30, 2012 recognized in net income (loss)*
(In millions)	July 1,																	Level 3		of Level 3			September 30,
	2012																						2012
Fixed maturity securities:
Corporate and other bonds	$	488	$	1		$	(4	)	$	50		$	(5	)	$	(11	)	$	—	$	(260	)	$	259	$	(1	)
States, municipalities and political subdivisions	89		—			—			—			—			—			—		—			89		—
Asset-backed:
Residential mortgage-backed	443		(17		)	20			21			—			(8		)	—		(22		)	437		(18		)
Commercial mortgage-backed	166		4			6			12			—			(17		)	11		(65		)	117		—
Other asset-backed	434		2			5			143			(117		)	(34		)	—		(62		)	371		—
Total asset-backed	1,043		(11		)	31			176			(117		)	(59		)	11		(149		)	925		(18		)
Redeemable preferred stock	27		—			(1		)	—			—			—			—		—			26		—
Total fixed maturity securities	1,647		(10		)	26			226			(122		)	(70		)	11		(409		)	1,299		(19		)
Equity securities	93		(19		)	(10		)	—			—			—			—		(14		)	50		(19		)
Other invested assets, including derivatives, net	10		—			—			—			—			—			—		—			10		—
Short term investments	4		—			—			7			(4		)	—			1		—			8		—
Life settlement contracts	116		7			—			—			—			(10		)	—		—			113		—
Separate account business	3		—			—			—			—			—			—		—			3		—
Total	$	1,873	$	(22	)	$	16		$	233		$	(126	)	$	(80	)	$	12	$	(423	)	$	1,483	$	(38	)
The tables below present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the nine months ended September 30, 2013 and 2012.
Level 3	Balance at		Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at		Unrealized gains (losses) on Level 3 assets and liabilities held at September 30, 2013 recognized in net income (loss)*
(In millions)	January 1,																	Level 3		of Level 3			September 30,
	2013																						2013
Fixed maturity securities:
Corporate and other bonds	$	219	$	2		$	(1	)	$	129		$	(96	)	$	(34	)	$	43	$	(51	)	$	211	$	(2	)
States, municipalities and political subdivisions	96		(3		)	1			122			(79		)	(20		)	5		(27		)	95		—
Asset-backed:
Residential mortgage-backed	413		2			(21		)	116			(10		)	(53		)	4		(81		)	370		(3		)
Commercial mortgage-backed	129		—			7			88			—			(10		)	21		(78		)	157		—
Other asset-backed	368		3			(1		)	230			(132		)	(30		)	—		(5		)	433		(2		)
Total asset-backed	910		5			(15		)	434			(142		)	(93		)	25		(164		)	960		(5		)
Redeemable preferred stock	26		(1		)	—			—			—			(25		)	—		—			—		—
Total fixed maturity securities	1,251		3			(15		)	685			(317		)	(172		)	73		(242		)	1,266		(7		)
Equity securities	34		(22		)	2			—			—			—			—		(1		)	13		(22		)
Other invested assets, including derivatives, net	—		—			—			—			(1		)	1			—		—			—		—
Short term investments	6		—			—			—			(6		)	—			—		—			—		—
Life settlement contracts	100		14			—			—			—			(24		)	—		—			90		(1		)
Separate account business	2		—			—			—			—			—			—		—			2		—
Total	$	1,393	$	(5	)	$	(13	)	$	685		$	(324	)	$	(195	)	$	73	$	(243	)	$	1,371	$	(30	)
Level 3	Balance at		Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at		Unrealized gains (losses) on Level 3 assets and liabilities held at September 30, 2012 recognized in net income (loss)*
(In millions)	January 1,																	Level 3		of Level 3			September 30,
	2012																						2012
Fixed maturity securities:
Corporate and other bonds	$	482	$	7		$	2		$	197		$	(118	)	$	(43	)	$	42	$	(310	)	$	259	$	(1	)
States, municipalities and political subdivisions	171		—			3			—			—			(85		)	—		—			89		—
Asset-backed:
Residential mortgage-backed	452		(15		)	(2		)	81			—			(24		)	—		(55		)	437		(18		)
Commercial mortgage-backed	59		6			14			141			(12		)	(21		)	11		(81		)	117		—
Other asset-backed	343		8			8			501			(293		)	(93		)	—		(103		)	371		—
Total asset-backed	854		(1		)	20			723			(305		)	(138		)	11		(239		)	925		(18		)
Redeemable preferred stock	—		—			(1		)	53			(26		)	—			—		—			26		—
Total fixed maturity securities	1,507		6			24			973			(449		)	(266		)	53		(549		)	1,299		(19		)
Equity securities	67		(19		)	6			26			(16		)	—			—		(14		)	50		(21		)
Other invested assets, including derivatives, net	10		—			—			—			—			—			—		—			10		—
Short term investments	27		—			—			23			(4		)	(39		)	1		—			8		—
Life settlement contracts	117		30			—			—			—			(34		)	—		—			113		3
Separate account business	23		—			—			—			(20		)	—			—		—			3		—
Total	$	1,751	$	17		$	30		$	1,022		$	(489	)	$	(339	)	$	54	$	(563	)	$	1,483	$	(37	)
* Net realized and unrealized gains and losses shown above are reported in Net income (loss) as follows:
Major Category of Assets and Liabilities		Condensed Consolidated Statements of Operations Line Items
Fixed maturity securities available-for-sale		Net realized investment gains (losses)
Fixed maturity securities trading		Net investment income
Equity securities		Net realized investment gains (losses)
Other invested assets - Derivative financial instruments held in a trading portfolio		Net investment income
Other invested assets - Derivative financial instruments not held in a trading portfolio		Net realized investment gains (losses)
Other invested assets - Overseas deposits		Net investment income
Life settlement contracts		Other revenues
Securities shown in the Level 3 tables on the previous pages may be transferred in or out of Level 3 based on the availability of observable market information used to determine the fair value of the security. The availability of observable market information varies based on market conditions and trading volume and may cause securities to move in and out of Level 3 from reporting period to reporting period. There were no transfers between Level 1 and Level 2 during the three or nine months ended September 30, 2013 and $106 million of transfers from Level 2 to Level 1 during the three and nine months ended September 30, 2012. The Company's policy is to recognize transfers between levels at the beginning of quarterly reporting periods.
Valuation Methodologies and Inputs
The following section describes the valuation methodologies and relevant inputs used to measure different financial instruments at fair value, including an indication of the level in the fair value hierarchy in which the instruments are generally classified.
Fixed Maturity Securities
Fixed maturity securities are valued using methodologies that model information generated by market transactions involving identical or comparable assets, as well as discounted cash flow methodologies. Common inputs include prices from recently executed transactions of similar securities, broker/dealer quotes, benchmark yields, spreads off benchmark yields, interest rates, and U.S. Treasury or swap curves. Specifically for asset-backed securities, key inputs include prepayment and default projections based on past performance of the underlying collateral and current market data.
Level 1 securities include exchange traded bonds, highly liquid U.S. and foreign government bonds, and redeemable preferred stock, valued using quoted market prices. Level 2 securities include most other fixed maturity securities as the significant inputs are observable in the marketplace. Securities are generally assigned to Level 3 in cases where broker/dealer quotes are significant inputs to the valuation and there is a lack of transparency as to whether these quotes are based on information that is observable in the marketplace. Level 3 securities also include tax-exempt auction rate certificates and private placement debt securities. Fair value of auction rate securities is determined utilizing a pricing model with three primary inputs. The interest rate and spread inputs are observable from like instruments while the expected call date assumption is unobservable due to the uncertain nature of principal prepayments prior to maturity and the credit spread adjustment that is security specific. Fair value of certain private placement debt securities is determined using internal models with inputs that are not market observable.
Equity Securities
Level 1 equity securities include publicly traded securities valued using quoted market prices. Level 2 securities are primarily non-redeemable preferred stocks and common stocks valued using pricing for similar securities, recently executed transactions, broker/dealer quotes and other pricing models utilizing market observable inputs. Level 3 securities are priced using internal models with inputs that are not market observable.
Other Invested Assets
Level 1 securities include exchange traded derivatives, primarily futures, valued using quoted market prices. Level 2 securities primarily include overseas deposits, which can be redeemed at net asset value in 90 days or less, and derivatives, primarily currency forwards valued using observable market forward rates. Over-the-counter derivatives, principally interest rate swaps, total return swaps, credit default swaps, equity warrants and options, are valued using inputs including broker/dealer quotes and are classified within Level 3 of the valuation hierarchy due to a lack of transparency as to whether these quotes are based on information that is observable in the marketplace.
Short Term Investments
Securities that are actively traded or have quoted prices are classified as Level 1. These securities include money market funds and treasury bills. Level 2 primarily includes commercial paper, for which all inputs are market observable. Fixed maturity securities purchased within one year of maturity are classified consistent with fixed maturity securities discussed above. Short term investments as presented in the tables above differ from the amounts presented on the Condensed Consolidated Balance Sheets because certain short term investments, such as time deposits, are not measured at fair value.
Life Settlement Contracts
The fair values of life settlement contracts are determined as the present value of the anticipated death benefits less anticipated premium payments based on contract terms that are distinct for each insured, as well as the Company's own assumptions for mortality, premium expense, and the rate of return that a buyer would require on the contracts, as no comparable market pricing data is available.
Separate Account Business
Separate account business includes fixed maturity securities, equities and short term investments. The valuation methodologies and inputs for these asset types have been described above.
Significant Unobservable Inputs
The table below presents quantitative information about the significant unobservable inputs utilized by the Company in the fair value measurements of Level 3 assets. Valuations for assets and liabilities not presented in the table below are primarily based 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 the Company.
Assets	Fair Value at September 30, 2013		Valuation Technique(s)		Unobservable Input(s)	Range
(In millions)						(Weighted Average)
Fixed maturity securities	$	179	Discounted cash flow		Expected call date	2.1 - 5.3 years (3.8 years)
					Credit spread	1.92% - 26.24% (3.80%)
Equity securities	$	13	Market approach		Private offering price	$289.80 - $4,273.77 per share
						($1,337.14 per share)
Life settlement contracts	$	90	Discounted cash flow		Discount rate risk premium	9%
					Mortality assumption	69% - 883% (208.8%)
Assets	Fair Value at December 31, 2012		Valuation Technique(s)		Unobservable Input(s)	Range
(In millions)						(Weighted Average)
Fixed maturity securities	$	121	Discounted cash flow		Expected call date	3.3 - 5.3 years (4.3 years)
					Credit spread adjustment	0.02% - 0.48% (0.17%)
	$	72	Market approach		Private offering price	$42.39 - $102.32 ($100.11)
Equity securities	$	34	Market approach		Private offering price	$4.54 - $3,842.00 per share
						($571.17 per share)
Life settlement contracts	$	100	Discounted cash flow		Discount rate risk premium	9%
					Mortality assumption	69% - 883% (208.9%)
For fixed maturity securities, an increase to the expected call date and credit spread assumptions would result in a lower fair value measurement. For equity securities, an increase in the private offering price would result in a higher fair value measurement. For life settlement contracts, an increase in the discount rate risk premium or decrease in the mortality assumption would result in a lower fair value measurement.
Financial Assets and Liabilities Not Measured at Fair Value
The carrying amount and estimated fair value of the Company's financial instrument assets and liabilities which are not measured at fair value on the Condensed Consolidated Balance Sheets are listed in the tables below.
September 30, 2013	Carrying		Estimated Fair Value
(In millions)	Amount		Level 1			Level 2			Level 3			Total
Financial assets
Notes receivable for the issuance of common stock	$	22	$	—		$	—		$	22		$	22
Mortgage loans	440		—			—			452			452
Financial liabilities
Premium deposits and annuity contracts	$	68	$	—		$	—		$	69		$	69
Long term debt	2,559		—			2,928			—			2,928
31-Dec-12	Carrying		Estimated Fair Value
(In millions)	Amount		Level 1			Level 2			Level 3			Total
Financial assets
Notes receivable for the issuance of common stock	$	21	$	—		$	—		$	21		$	21
Mortgage loans	401		—			—			418			418
Financial liabilities
Premium deposits and annuity contracts	$	100	$	—		$	—		$	104		$	104
Short term debt	13		—			13			—			13
Long term debt	2,557		—			3,016			—			3,016
The following methods and assumptions were used to estimate the fair value of these financial assets and liabilities.
The fair values of Notes receivable for the issuance of common stock were estimated using discounted cash flows utilizing interest rates currently offered for obligations securitized with similar collateral, adjusted for specific note receivable risk.
The fair values of Mortgage loans were based on the present value of the expected future cash flows discounted at the current interest rate for origination of similar quality loans, adjusted for specific loan risk.
Premium deposits and annuity contracts were valued based on cash surrender values or estimated fair values of policyholder liabilities, net of amounts ceded related to sold business.
The Company's senior notes and debentures were valued based on observable market prices. The fair value for other debt was estimated using discounted cash flows based on current incremental borrowing rates for similar borrowing arrangements.
The carrying amounts reported on the Condensed Consolidated Balance Sheets for Cash, Short term investments not carried at fair value, Accrued investment income and certain other assets and other liabilities approximate fair value due to the short term nature of these items. These assets and liabilities are not listed in the tables above.

Claim_and_Claim_Adjustment_Exp

Claim and Claim Adjustment Expense Reserves	9 Months Ended
	Sep. 30, 2013
Insurance Loss Reserves [Abstract]
Claim and Claim Adjustment Expense Reserves	Note F. Claim and Claim Adjustment Expense Reserves
	The Company's property and casualty insurance claim and claim adjustment expense reserves represent the estimated amounts necessary to resolve all outstanding claims, including IBNR claims as of the reporting date. The Company's reserve projections are based primarily on detailed analysis of the facts in each case, the Company's experience with similar cases and various historical development patterns. Consideration is given to such historical patterns as field reserving trends and claims settlement practices, loss payments, pending levels of unpaid claims and product mix, as well as court decisions, economic conditions including inflation, and public attitudes. All of these factors can affect the estimation of claim and claim adjustment expense reserves.
	Establishing claim and claim adjustment expense reserves, including claim and claim adjustment expense reserves for catastrophic events that have occurred, is an estimation process. Many factors can ultimately affect the final settlement of a claim and, therefore, the necessary reserve. Changes in the law, results of litigation, medical costs, the cost of repair materials and labor rates can all affect ultimate claim costs. In addition, time can be a critical part of reserving determinations since the longer the span between the incidence of a loss and the payment or settlement of the claim, the more variable the ultimate settlement amount can be. Accordingly, short-tail claims, such as property damage claims, tend to be more reasonably estimable than long-tail claims, such as workers’ compensation, general liability and professional liability claims. Adjustments to prior year reserve estimates, if necessary, are reflected in the results of operations in the period that the need for such adjustments is determined. There can be no assurance that the Company's ultimate cost for insurance losses will not exceed current estimates.
	Catastrophes are an inherent risk of the property and casualty insurance business and have contributed to material period-to-period fluctuations in the Company's results of operations and/or equity. The Company reported catastrophe losses, net of reinsurance, of $42 million and $146 million for the three and nine months ended September 30, 2013. Catastrophe losses in 2013 related primarily to U.S. storms. The Company reported catastrophe losses, net of reinsurance, of $27 million and $123 million for the three and nine months ended September 30, 2012.
	Net Prior Year Development
	The following tables and discussion include the net prior year development recorded for CNA Specialty, CNA Commercial, Hardy and Corporate & Other Non-Core segments.
	Net Prior Year Development
	Three months ended September 30, 2013
	(In millions)	CNA Specialty			CNA Commercial			Hardy			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(74	)	$	(3	)	$	(6	)	$	2		$	(81	)
	Pretax (favorable) unfavorable premium development	(3		)	7			1			—			5
	Total pretax (favorable) unfavorable net prior year development	$	(77	)	$	4		$	(5	)	$	2		$	(76	)
	Three months ended September 30, 2012
	(In millions)	CNA Specialty			CNA Commercial			Hardy			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(39	)	$	2		$	(6	)	$	3		$	(40	)
	Pretax (favorable) unfavorable premium development	(1		)	(5		)	—			(1		)	(7		)
	Total pretax (favorable) unfavorable net prior year development	$	(40	)	$	(3	)	$	(6	)	$	2		$	(47	)
	Nine months ended September 30, 2013
	(In millions)	CNA Specialty			CNA Commercial			Hardy			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(130	)	$	13		$	5		$	—		$	(112	)
	Pretax (favorable) unfavorable premium development	(16		)	(8		)	7			1			(16		)
	Total pretax (favorable) unfavorable net prior year development	$	(146	)	$	5		$	12		$	1		$	(128	)
	Nine months ended September 30, 2012
	(In millions)	CNA Specialty			CNA Commercial			Hardy			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(80	)	$	(25	)	$	(6	)	$	1		$	(110	)
	Pretax (favorable) unfavorable premium development	(15		)	(41		)	—			1			(55		)
	Total pretax (favorable) unfavorable net prior year development	$	(95	)	$	(66	)	$	(6	)	$	2		$	(165	)
	For the nine months ended September 30, 2012, favorable premium development was recorded for CNA Commercial primarily due to premium adjustments on auditable policies arising from increased exposures.
	CNA Specialty
	The following table provides further detail of the net prior year claim and allocated claim adjustment expense reserve development (development) recorded for the CNA Specialty segment for the three and nine months ended September 30, 2013 and 2012.
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Medical Professional Liability	$	9		$	9		$	(11	)	$	(6	)
	Other Professional Liability	(4		)	1			(28		)	(1		)
	Surety	(76		)	(60		)	(74		)	(59		)
	Warranty	—			—			—			(1		)
	Other	(3		)	11			(17		)	(13		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(74	)	$	(39	)	$	(130	)	$	(80	)
	Three Month Comparison
	2013
	Favorable development for surety coverages was primarily due to better than expected large loss emergence in accident years 2011 and prior.
	2012
	Favorable development for surety coverages was primarily due to better than expected loss emergence in accident years 2010 and prior.
	Other includes standard property and casualty coverages provided to CNA Specialty customers. Unfavorable development for other coverages was primarily due to an unfavorable outcome on an individual general liability claim in accident year 2009.
	Nine Month Comparison
	2013
	Overall, favorable development for medical professional liability reflects favorable experience in accident years 2009 and prior. Unfavorable development was recorded for accident years 2010 and 2011 due to higher than expected large loss activity.
	Overall, favorable development for other professional liability was related to better than expected loss emergence in accident years 2007 through 2009. Unfavorable development was recorded in accident years 2010 through 2012 related to an increase in severity.
	Favorable development for surety coverages was primarily due to better than expected large loss emergence in accident years 2011 and prior.
	Favorable development for other coverages was primarily due to better than expected loss emergence in property coverages in accident years 2010 and subsequent.
	2012
	Favorable development for surety coverages was primarily due to better than expected loss emergence in accident years 2010 and prior.
	Overall, favorable development for other coverages was primarily due to favorable loss emergence in property and workers’ compensation coverages in accident years 2005 and subsequent. Unfavorable development was recorded in accident year 2009 primarily due to an unfavorable outcome on an individual general liability claim.
	CNA Commercial
	The following table provides further detail of the development recorded for the CNA Commercial segment for the three and nine months ended September 30, 2013 and 2012.
Periods ended September 30	Three Months						Nine Months
(In millions)	2013			2012			2013			2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
Commercial Auto	$	4		$	9		$	1		$	11
General Liability	(18		)	(21		)	(24		)	(26		)
Workers’ Compensation	26			24			96			13
Property and Other	(15		)	(10		)	(60		)	(23		)
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(3	)	$	2		$	13		$	(25	)
Three Month Comparison
2013
Favorable development for general liability coverages was primarily related to better than expected loss emergence in accident years 2005 through 2007 and 2012.
Unfavorable development for workers’ compensation was primarily due to increased frequency and severity on claims related to Defense Base Act (DBA) contractors in accident year 2012.
Favorable development for property and other coverages was primarily related to favorable loss emergence in non-catastrophe losses in accident years 2010 through 2012.
2012
Favorable development for general liability coverages was primarily due to favorable loss emergence in accident years 2003 and prior related to large account business.
Unfavorable development for workers’ compensation was primarily due to increased medical severity in accident years 2010 and 2011.
Favorable development for property and other coverages was due to favorable loss emergence in non-catastrophe losses in accident years 2009 and subsequent.
Nine Month Comparison
2013
Favorable development for general liability coverages was primarily related to better than expected loss emergence in accident years 2009 and prior and 2012.
Unfavorable development for workers’ compensation includes the Company's response to legislation enacted during 2013 related to the New York Fund for Reopened Cases. The law change necessitated an increase in reserves as re-opened workers’ compensation claims can no longer be turned over to the state for handling and payment after December 31, 2013. Additional unfavorable development was recorded in accident year 2012 related to increased frequency and severity on claims related to DBA contractors and in accident year 2010 due to higher than expected large losses and increased severity in the state of California.
Favorable development for property and other coverages was primarily related to favorable outcomes on litigated catastrophe claims in accident years 2005 and 2010 and favorable loss emergence in non-catastrophe losses in accident years 2010 through 2012.
2012
Unfavorable development for commercial auto coverages was primarily due to higher than expected frequency in accident years 2009 and subsequent.
Favorable development for general liability coverages was primarily due to favorable loss emergence in accident years 2003 and prior related to large account business.
Overall, unfavorable development for workers’ compensation was primarily due to increased medical severity in accident years 2010 and 2011 and losses related to favorable premium development in accident year 2011. Favorable development was recorded in accident years 2001 and prior reflecting favorable experience.
Favorable development for property and other coverages was due to a favorable outcome on an individual claim in accident year 2005 and favorable loss emergence in non-catastrophe losses in accident years 2009 through 2011.
Hardy
The following table provides further detail of the development recorded for the Hardy segment for the three and nine months ended September 30, 2013 and 2012.
Periods ended September 30	Three Months						Nine Months
(In millions)	2013			2012			2013			2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
Marine and Aviation	$	—		$	1		$	3		$	1
Non-Marine Property	1			(5		)	8			(5		)
Property Treaty	(5		)	—			(3		)	—
Specialty	(2		)	(2		)	(3		)	(2		)
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(6	)	$	(6	)	$	5		$	(6	)
Three Months
2013
Favorable development for property treaty was due to favorable emergence of losses from catastrophe events in 2011 and 2012. Favorable development for specialty was primarily due to favorable outcomes on several large losses.
Nine Months
2013
Unfavorable development for non-marine property was primarily due to 2011 catastrophe events, including the Thailand floods and the New Zealand Lyttelton earthquake.
Favorable development for property treaty was due to favorable emergence of losses from catastrophe events in 2011 and 2012. Favorable development for specialty was primarily due to favorable outcomes on several large losses.

Legal_Proceedings_and_Continge

Legal Proceedings and Contingent Liabilities	9 Months Ended
	Sep. 30, 2013
Legal Proceedings and Contingent Liabilities [Abstract]
Legal Proceedings and Contingent Liabilities	Note G. Legal Proceedings and Contingent Liabilities
	The Company is a party to routine litigation incidental to its business, which, based on the facts and circumstances currently known, is not material to the Condensed Consolidated Financial Statements.

Benefit_Plans

Benefit Plans	9 Months Ended
	Sep. 30, 2013
Compensation and Retirement Disclosure [Abstract]
Benefit Plans	Note H. Benefit Plans
	The components of net periodic cost (benefit) are presented in the following table.
	Net Periodic Cost (Benefit)
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Pension cost (benefit)
	Service cost	$	3		$	3		$	9		$	9
	Interest cost on projected benefit obligation	30			34			90			101
	Expected return on plan assets	(45		)	(43		)	(135		)	(128		)
	Amortization of net actuarial (gain) loss	10			10			34			29
	Settlement loss	3			—			3			—
	Net periodic pension cost (benefit)	$	1		$	4		$	1		$	11
	Postretirement cost (benefit)
	Interest cost on projected benefit obligation	$	—		$	1		$	1		$	2
	Amortization of prior service credit	(4		)	(4		)	(13		)	(13		)
	Amortization of net actuarial (gain) loss	1			—			1			—
	Net periodic postretirement cost (benefit)	$	(3	)	$	(3	)	$	(11	)	$	(11	)

Other_Intangible_Assets

Other Intangible Assets	9 Months Ended
	Sep. 30, 2013
Schedule of Other Intangible Assets [Abstract]
Other Intangible Assets	Note I. Other Intangible Assets
	Other intangible assets are presented in the following table.
		30-Sep-13				31-Dec-12
	(In millions)	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
	Finite-lived intangible assets:
	Value of business acquired	$	62	$	62	$	62	$	43
	Trade name	8		1		8		—
	Distribution channel	13		1		13		—
	Total finite-lived intangible assets	83		64		83		43
	Indefinite-lived intangible assets	73				73
	Total other intangible assets	$	156	$	64	$	156	$	43
	For the three and nine months ended September 30, 2013, amortization expense of $1 million and $14 million was included in Amortization of deferred acquisition costs and $(1) million and $4 million was included in Other operating expenses in the Statement of Operations for the Hardy segment. For the three and nine months ended September 30, 2012, amortization expense of $18 million was included in Amortization of deferred acquisition costs and $6 million was included in Other operating expenses in the Statement of Operations for the Hardy segment. The gross carrying amounts and accumulated amortization in the table above may change from period to period as a result of foreign currency translation. Estimated future amortization expense for intangible assets is $1 million for the remainder of 2013, $4 million in 2014, $1 million in 2015 and $2 million in years 2016, 2017 and 2018.

Commitments_Contingencies_and_

Commitments, Contingencies, and Guarantees	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies, and Guarantees	Note J. Commitments, Contingencies, and Guarantees
	Commitments and Contingencies
	The Company holds an investment in a real estate joint venture. In the normal course of business, the Company, on a joint and several basis with other unrelated insurance company shareholders, has committed to continue funding the operating deficits of this joint venture. Additionally, the Company and the other unrelated shareholders, on a joint and several basis, have guaranteed an operating lease for an office building, which expires in 2016. The guarantee of the operating lease is a parallel guarantee to the commitment to fund operating deficits; consequently, the separate guarantee to the lessor is not expected to be triggered as long as the joint venture continues to be funded by its shareholders which provide liquidity to make its annual lease payments.
	In the event that the other parties to the joint venture are unable to meet their commitments in funding the operations of this joint venture, the Company would be required to assume the obligation for the entire office building operating lease. The Company does not believe it is likely that it will be required to do so. However, the maximum potential future lease payments and other related costs at September 30, 2013 that the Company could be required to pay under this guarantee, in excess of amounts already recorded, were approximately $90 million. If the Company were required to assume the entire lease obligation, the Company would have the right to pursue reimbursement from the other shareholders and the right to all sublease revenues.
	Guarantees
	In the course of selling business entities and assets to third parties, the Company has agreed to indemnify purchasers for losses arising out of breaches of representation and warranties with respect to the business entities or assets being sold, including, in certain cases, losses arising from undisclosed liabilities or certain named litigation. Such indemnification provisions generally survive for periods ranging from nine months following the applicable closing date to the expiration of the relevant statutes of limitation. As of September 30, 2013, the aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third party loans was $723 million.
	In addition, the Company has agreed to provide indemnification to third party purchasers for certain losses associated with sold business entities or assets that are not limited by a contractual monetary amount. As of September 30, 2013, the Company had outstanding unlimited indemnifications in connection with the sales of certain of its business entities or assets that included tax liabilities arising prior to a purchaser's ownership of an entity or asset, defects in title at the time of sale, employee claims arising prior to closing and in some cases losses arising from certain litigation and undisclosed liabilities. These indemnification agreements survive until the applicable statutes of limitation expire or until the agreed upon contract terms expire.
	As of September 30, 2013 and December 31, 2012, the Company had recorded liabilities of approximately $7 million related to indemnification agreements and management believes that it is not likely that any future indemnity claims will be significantly greater than the amounts recorded.

Business_Segments

Business Segments	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]
Business Segments	Note K. Business Segments
	The Company's core property and casualty commercial insurance operations are reported in three business segments: CNA Specialty, CNA Commercial and Hardy. The Company's non-core operations are managed in two segments: Life & Group Non-Core and Corporate & Other Non-Core.
	The accounting policies of the segments are the same as those described in Note A of the Consolidated Financial Statements within CNAF's Annual Report on Form 10-K for the year ended December 31, 2012. The Company manages most of its assets on a legal entity basis, while segment operations are generally conducted across legal entities. As such, only insurance and reinsurance receivables, insurance reserves, deferred acquisition costs and goodwill are readily identifiable for all individual segments. Distinct investment portfolios are not maintained for every individual segment; accordingly, allocation of assets to each segment is not performed. Therefore, a significant portion of net investment income and realized investment gains or losses are allocated primarily based on each segment's net carried insurance reserves, as adjusted. All significant intersegment income and expense has been eliminated. Income taxes have been allocated on the basis of the taxable income of the segments.
	In the following tables, certain financial measures are presented to provide information used by management to monitor the Company's operating performance. Management utilizes these financial measures to monitor the Company's insurance operations and investment portfolio. Net operating income, which is derived from certain income statement amounts, is used by management to monitor performance of the Company's insurance operations. The Company's investment portfolio is monitored by management through analysis of various factors including unrealized gains and losses on securities, portfolio duration and exposure to market and credit risk. Based on such analyses, the Company may recognize an OTTI loss on an investment security in accordance with its policy, or sell a security, which may produce realized gains and losses.
	Net operating income (loss) is calculated by excluding from net income (loss) the after-tax effects of 1) net realized investment gains or losses and 2) any cumulative effects of changes in accounting guidance. The calculation of net operating income excludes net realized investment gains or losses because net realized investment gains or losses are largely discretionary, except for some losses related to OTTI, and are generally driven by economic factors that are not necessarily consistent with key drivers of underwriting performance, and are therefore not considered an indication of trends in insurance operations.
	The Company's results of operations and selected balance sheet items by segment are presented in the following tables.
	Three months ended September 30, 2013	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	768		$	832		$	86		$	140		$	—		$	(1	)	$	1,825
	Net investment income	159			219			1			209			9			—			597
	Other revenues	67			10			1			(3		)	3			—			78
	Total operating revenues	994			1,061			88			346			12			(1		)	2,500
	Claims, Benefits and Expenses
	Net incurred claims and benefits	427			565			35			377			4			—			1,408
	Policyholders’ dividends	3			1			—			2			—			—			6
	Amortization of deferred acquisition costs	161			148			25			7			—			—			341
	Other insurance related expenses	64			141			14			34			1			(1		)	253
	Other expenses	58			7			2			5			49			—			121
	Total claims, benefits and expenses	713			862			76			425			54			(1		)	2,129
	Operating income (loss) before income tax	281			199			12			(79		)	(42		)	—			371
	Income tax (expense) benefit on operating income (loss)	(94		)	(68		)	—			44			16			—			(102		)
	Net operating income (loss)	187			131			12			(35		)	(26		)	—			269
	Net realized investment gains (losses), pre-tax	2			1			—			—			1			—			4
	Income tax (expense) benefit on net realized investment gains (losses)	(1		)	—			1			—			(1		)	—			(1		)
	Net realized investment gains (losses)	1			1			1			—			—			—			3
	Net income (loss)	$	188		$	132		$	13		$	(35	)	$	(26	)	$	—		$	272
	Three months ended September 30, 2012	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	738		$	840		$	64		$	141		$	(2	)	$	—		$	1,781
	Net investment income	159			230			2			201			9			—			601
	Other revenues	58			11			—			1			7			(1		)	76
	Total operating revenues	955			1,081			66			343			14			(1		)	2,458
	Claims, Benefits and Expenses
	Net incurred claims and benefits	460			591			21			350			8			—			1,430
	Policyholders’ dividends	1			3			—			1			—			—			5
	Amortization of deferred acquisition costs	156			151			20			6			—			—			333
	Other insurance related expenses	73			146			13			35			1			—			268
	Other expenses	53			7			7			8			42			(1		)	116
	Total claims, benefits and expenses	743			898			61			400			51			(1		)	2,152
	Operating income (loss) before income tax	212			183			5			(57		)	(37		)	—			306
	Income tax (expense) benefit on operating income (loss)	(76		)	(58		)	(2		)	35			11			—			(90		)
	Net operating income (loss)	136			125			3			(22		)	(26		)	—			216
	Net realized investment gains (losses), pre-tax	2			10			(1		)	(3		)	—			—			8
	Income tax (expense) benefit on net realized investment gains (losses)	(2		)	(3		)	—			1			1			—			(3		)
	Net realized investment gains (losses)	—			7			(1		)	(2		)	1			—			5
	Net income (loss)	$	136		$	132		$	2		$	(24	)	$	(25	)	$	—		$	221
	Nine months ended September 30, 2013	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	2,237		$	2,509		$	226		$	419		$	—		$	(2	)	$	5,389
	Net investment income	480			680			3			620			25			—			1,808
	Other revenues	190			85			1			2			8			(1		)	285
	Total operating revenues	2,907			3,274			230			1,041			33			(3		)	7,482
	Claims, Benefits and Expenses
	Net incurred claims and benefits	1,344			1,809			107			1,082			6			—			4,348
	Policyholders’ dividends	5			5			—			6			—			—			16
	Amortization of deferred acquisition costs	467			450			66			21			—			—			1,004
	Other insurance related expenses	200			426			43			100			1			(2		)	768
	Other expenses	172			18			15			12			134			(1		)	350
Total claims, benefits and expenses	2,188			2,708			231			1,221			141			(3		)	6,486
Operating income (loss) before income tax	719			566			(1		)	(180		)	(108		)	—			996
Income tax (expense) benefit on operating income (loss)	(244		)	(198		)	3			109			38			—			(292		)
Net operating income (loss)	475			368			2			(71		)	(70		)	—			704
Net realized investment gains (losses), pre-tax	(1		)	(7		)	2			14			10			—			18
Income tax (expense) benefit on net realized investment gains (losses)	—			3			—			(5		)	(4		)	—			(6		)
Net realized investment gains (losses)	(1		)	(4		)	2			9			6			—			12
Net income (loss)	$	474		$	364		$	4		$	(62	)	$	(64	)	$	—		$	716
September 30, 2013
(In millions)
Reinsurance receivables	$	613		$	1,107		$	227		$	1,229		$	2,627		$	—		$	5,803
Insurance receivables	$	746		$	1,112		$	211		$	10		$	4		$	—		$	2,083
Deferred acquisition costs	$	320		$	270		$	52		$	—		$	—		$	—		$	642
Goodwill	$	117		$	—		$	37		$	—		$	—		$	—		$	154
Insurance reserves
Claim and claim adjustment expenses	$	6,846		$	10,763		$	432		$	3,050		$	2,871		$	—		$	23,962
Unearned premiums	1,811			1,604			274			132			—			(1		)	3,820
Future policy benefits	—			—			—			10,681			—			—			10,681
Policyholders’ funds	10			15			—			102			—			—			127
Nine months ended September 30, 2012	CNA			CNA			Hardy (a)			Life &			Corporate
	Specialty			Commercial						Group			& Other
(In millions)										Non-Core			Non-Core			Eliminations			Total
Operating revenues
Net earned premiums	$	2,163		$	2,452		$	64		$	421		$	(1	)	$	(1	)	$	5,098
Net investment income	446			646			2			600			25			—			1,719
Other revenues	171			31			—			15			14			(1		)	230
Total operating revenues	2,780			3,129			66			1,036			38			(2		)	7,047
Claims, Benefits and Expenses
Net incurred claims and benefits	1,376			1,749			21			1,009			(5		)	—			4,150
Policyholders’ dividends	—			9			—			5			—			—			14
Amortization of deferred acquisition costs	458			437			20			22			—			—			937
Other insurance related expenses	222			425			13			106			1			(1		)	766
Other expenses	153			24			7			18			137			(1		)	338
Total claims, benefits and expenses	2,209			2,644			61			1,160			133			(2		)	6,205
Operating income (loss) before income tax	571			485			5			(124		)	(95		)	—			842
Income tax (expense) benefit on operating income (loss)	(197		)	(164		)	(2		)	86			29			—			(248		)
Net operating income (loss)	374			321			3			(38		)	(66		)	—			594
Net realized investment gains (losses), pre-tax	18			34			(1		)	14			1			—			66
Income tax (expense) benefit on net realized investment gains (losses)	(6		)	(12		)	—			(5		)	—			—			(23		)
Net realized investment gains (losses)	12			22			(1		)	9			1			—			43
Net income (loss)	$	386		$	343		$	2		$	(29	)	$	(65	)	$	—		$	637
December 31, 2012
(In millions)
Reinsurance receivables	$	665		$	1,155		$	294		$	1,273		$	2,844		$	—		$	6,231
Insurance receivables	$	673		$	1,116		$	181		$	9		$	4		$	—		$	1,983
Deferred acquisition costs	$	300		$	269		$	29		$	—		$	—		$	—		$	598
Goodwill	$	117		$	—		$	37		$	—		$	—		$	—		$	154
Insurance reserves
Claim and claim adjustment expenses	$	6,748		$	11,326		$	521		$	3,006		$	3,162		$	—		$	24,763
Unearned premiums	1,685			1,569			222			134			—			—			3,610
Future policy benefits	—			—			—			11,475			—			—			11,475
Policyholders’ funds	8			15			—			134			—			—			157
_______________________________
(a)	Included from date of acquisition.
The following table provides revenue by line of business for each reportable segment. Revenues are comprised of operating revenues and net realized investment gains and losses.
Revenues by Line of Business
Periods ended September 30	Three Months						Nine Months
(In millions)	2013			2012			2013			2012
CNA Specialty
International	$	59		$	53		$	177		$	163
Professional & Management Liability	720			700			2,107			2,039
Surety	126			124			365			364
Warranty & Alternative Risks	91			80			257			232
CNA Specialty revenues	996			957			2,906			2,798
CNA Commercial
Commercial Insurance	776			826			2,429			2,396
International	93			93			276			274
Small Business	193			172			562			493
CNA Commercial revenues	1,062			1,091			3,267			3,163
Hardy revenues	88			65			232			65
Life & Group Non-Core
Health	290			274			875			852
Life & Annuity	58			64			177			181
Other	(2		)	2			3			17
Life & Group Non-Core revenues	346			340			1,055			1,050
Corporate & Other Non-Core revenues	13			14			43			39
Eliminations	(1		)	(1		)	(3		)	(2		)
Total revenues	$	2,504		$	2,466		$	7,500		$	7,113

Changes_in_Accumulated_Other_C

Changes in Accumulated Other Comprehensive Income (Loss) by Component	9 Months Ended
	Sep. 30, 2013
Changes in Accumulated Other Comprehensive Income (Loss) [Abstract]
Changes in Accumulated Other Comprehensive Income (Loss) by Component	Note L. Changes in Accumulated Other Comprehensive Income (Loss) by Component
	The tables below present the changes in Accumulated other comprehensive income (loss) by component for the three and nine months ended September 30, 2013.
	Changes in Accumulated Other Comprehensive Income (Loss)
	(In millions)	Net unrealized gains (losses) on investments with OTTI losses			Net unrealized gains (losses) on other investments			Pension and postretirement benefits			Cumulative foreign currency translation adjustment			Total
	Balance at June 30, 2013	$	26		$	724		$	(711	)	$	87		$	126
	Other comprehensive income (loss) before reclassifications	(4		)	(68		)	—			56			(16		)
	Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(2), $3, $0, and $1	(1		)	2			(4		)	—			(3		)
	Other comprehensive income (loss) after tax (expense) benefit of $1, $38, $(3), $0, and $36	(3		)	(70		)	4			56			(13		)
	Balance at September 30, 2013	$	23		$	654		$	(707	)	$	143		$	113
	(In millions)	Net unrealized gains (losses) on investments with OTTI losses			Net unrealized gains (losses) on other investments			Pension and postretirement benefits			Cumulative foreign currency translation adjustment			Total
	Balance at January 1, 2013	$	20		$	1,371		$	(721	)	$	161		$	831
	Other comprehensive income (loss) before reclassifications	2			(706		)	—			(18		)	(722		)
	Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(5), $8, $0, and $3	(1		)	11			(14		)	—			(4		)
	Other comprehensive income (loss) after tax (expense) benefit of $(2), $387, $(8), $0, and $377	3			(717		)	14			(18		)	(718		)
	Balance at September 30, 2013	$	23		$	654		$	(707	)	$	143		$	113
	Amounts reclassified from Accumulated other comprehensive income (loss) shown above are reported in Net income (loss) as follows:
	Component of AOCI		Condensed Consolidated Statements of Operations Line Item Affected by Reclassifications
	Net unrealized gains (losses) on investments with OTTI losses		Net realized investment gains (losses)
	Net unrealized gains (losses) on other investments		Net realized investment gains (losses)
	Pension and postretirement benefits		Other operating expenses

Investments_Tables

Investments (Tables)	9 Months Ended
	Sep. 30, 2013
Investments [Abstract]
Net investment income	Net Investment Income
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Fixed maturity securities	$	504		$	507		$	1,501		$	1,528
	Short term investments	1			2			3			5
	Limited partnership investments	93			89			303			184
	Equity securities	3			4			9			10
	Mortgage loans	6			5			17			13
	Trading portfolio (a)	3			7			13			18
	Other	1			—			2			3
	Gross investment income	611			614			1,848			1,761
	Investment expense	(14		)	(13		)	(40		)	(42		)
	Net investment income	$	597		$	601		$	1,808		$	1,719
	___________________
	(a)	There were no net unrealized gains (losses) related to changes in fair value of trading securities still held included in net investment income for the three or nine months ended September 30, 2013 or 2012.
Net realized investment gains (losses)	Net Realized Investment Gains (Losses)
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Net realized investment gains (losses):
	Fixed maturity securities:
	Gross realized gains	$	51		$	75		$	132		$	193
	Gross realized losses	(44		)	(49		)	(98		)	(120		)
	Net realized investment gains (losses) on fixed maturity securities	7			26			34			73
	Equity securities:
	Gross realized gains	3			5			10			10
	Gross realized losses	(5		)	(20		)	(27		)	(24		)
	Net realized investment gains (losses) on equity securities	(2		)	(15		)	(17		)	(14		)
	Derivatives	(1		)	(1		)	(4		)	(1		)
	Short term investments and other	—			(2		)	5			8
	Net realized investment gains (losses)	$	4		$	8		$	18		$	66
Components of net other-than-temporary impairment losses recognized in earnings	The components of net other-than-temporary impairment (OTTI) losses recognized in earnings by asset type are summarized in the following table.
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	9		$	7		$	17		$	23
	States, municipalities and political subdivisions	—			17			—			17
	Asset-backed:
	Residential mortgage-backed	2			20			5			49
	Other asset-backed	1			—			2			—
	Total asset-backed	3			20			7			49
	U.S. Treasury and obligations of government-sponsored enterprises	—			—			—			1
	Total fixed maturity securities available-for-sale	12			44			24			90
	Equity securities available-for-sale:
	Common stock	3			1			5			5
	Preferred stock	2			19			22			19
	Total equity securities available-for-sale	5			20			27			24
	Net OTTI losses recognized in earnings	$	17		$	64		$	51		$	114
Summary of fixed maturity and equity securities	Summary of Fixed Maturity and Equity Securities
	September 30, 2013	Cost or			Gross			Gross			Estimated			Unrealized
		Amortized			Unrealized			Unrealized			Fair			OTTI
	(In millions)	Cost			Gains			Losses			Value			Losses (Gains)
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	19,616		$	1,695		$	151		$	21,160		$	—
	States, municipalities and political subdivisions	11,000			672			233			11,439			—
	Asset-backed:
	Residential mortgage-backed	4,779			141			101			4,819			(33		)
	Commercial mortgage-backed	1,942			99			24			2,017			(3		)
	Other asset-backed	942			16			2			956			—
	Total asset-backed	7,663			256			127			7,792			(36		)
	U.S. Treasury and obligations of government-sponsored enterprises	166			8			1			173			—
	Foreign government	547			17			3			561			—
	Redeemable preferred stock	94			12			—			106			—
	Total fixed maturity securities available-for-sale	39,086			2,660			515			41,231			$	(36	)
	Total fixed maturity securities trading	43			—			—			43
	Equity securities available-for-sale:
	Common stock	41			12			—			53
	Preferred stock	148			1			3			146
	Total equity securities available-for-sale	189			13			3			199
	Total	$	39,318		$	2,673		$	518		$	41,473
	December 31, 2012	Cost or			Gross			Gross			Estimated			Unrealized
		Amortized			Unrealized			Unrealized			Fair			OTTI
	(In millions)	Cost			Gains			Losses			Value			Losses (Gains)
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	19,530		$	2,698		$	21		$	22,207		$	—
	States, municipalities and political subdivisions	9,372			1,455			44			10,783			—
	Asset-backed:
	Residential mortgage-backed	5,745			246			71			5,920			(28		)
	Commercial mortgage-backed	1,692			147			17			1,822			(3		)
	Other asset-backed	929			23			—			952			—
	Total asset-backed	8,366			416			88			8,694			(31		)
	U.S. Treasury and obligations of government-sponsored enterprises	172			11			1			182			—
	Foreign government	588			25			—			613			—
	Redeemable preferred stock	113			13			1			125			—
	Total fixed maturity securities available-for-sale	38,141			4,618			155			42,604			$	(31	)
	Total fixed maturity securities trading	29			—			—			29
	Equity securities available-for-sale:
	Common stock	38			14			—			52
	Preferred stock	190			7			—			197
	Total equity securities available-for-sale	228			21			—			249
	Total	$	38,398		$	4,639		$	155		$	42,882
Securities in a gross unrealized loss position	Securities in a Gross Unrealized Loss Position
		Less than 12 Months						12 Months or Longer						Total
	September 30, 2013	Estimated			Gross			Estimated			Gross			Estimated			Gross
		Fair Value			Unrealized			Fair Value			Unrealized			Fair Value			Unrealized
	(In millions)				Losses						Losses						Losses
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	3,521		$	146		$	45		$	5		$	3,566		$	151
	States, municipalities and political subdivisions	2,413			179			122			54			2,535			233
	Asset-backed:
	Residential mortgage-backed	1,289			40			287			61			1,576			101
	Commercial mortgage-backed	449			20			79			4			528			24
	Other asset-backed	207			2			—			—			207			2
	Total asset-backed	1,945			62			366			65			2,311			127
	U.S. Treasury and obligations of government-sponsored enterprises	21			1			—			—			21			1
	Foreign government	76			3			—			—			76			3
	Total fixed maturity securities available-for-sale	7,976			391			533			124			8,509			515
	Equity securities available-for-sale:
	Preferred stock	86			3			—			—			86			3
	Total	$	8,062		$	394		$	533		$	124		$	8,595		$	518
		Less than 12 Months						12 Months or Longer						Total
	December 31, 2012	Estimated			Gross			Estimated			Gross			Estimated			Gross
		Fair Value			Unrealized			Fair Value			Unrealized			Fair Value			Unrealized
	(In millions)				Losses						Losses						Losses
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	846		$	13		$	108		$	8		$	954		$	21
	States, municipalities and political subdivisions	254			5			165			39			419			44
	Asset-backed:
	Residential mortgage-backed	583			5			452			66			1,035			71
	Commercial mortgage-backed	85			2			141			15			226			17
	Total asset-backed	668			7			593			81			1,261			88
	U.S. Treasury and obligations of government-sponsored enterprises	23			1			—			—			23			1
	Redeemable preferred stock	28			1			—			—			28			1
	Total	$	1,819		$	27		$	866		$	128		$	2,685		$	155
Activity related to the pretax fixed maturity credit loss component reflected within retained earnings for securities still held for which a portion of an OTTI loss was recognized in OCI	The following table summarizes the activity for the three and nine months ended September 30, 2013 and 2012 related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held at September 30, 2013 and 2012 for which a portion of an OTTI loss was recognized in Other comprehensive income (loss).
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Beginning balance of credit losses on fixed maturity securities	$	89		$	99		$	95		$	92
	Additional credit losses for securities for which an OTTI loss was previously recognized	1			2			2			23
	Credit losses for securities for which an OTTI loss was not previously recognized	—			—			—			2
	Reductions for securities sold during the period	(7		)	(3		)	(14		)	(11		)
	Reductions for securities the Company intends to sell or more likely than not will be required to sell	—			—			—			(8		)
	Ending balance of credit losses on fixed maturity securities	$	83		$	98		$	83		$	98
Contractual maturity	Contractual Maturity
		September 30, 2013						December 31, 2012
	(In millions)	Cost or			Estimated			Cost or			Estimated
		Amortized			Fair			Amortized			Fair
		Cost			Value			Cost			Value
	Due in one year or less	$	2,475		$	2,516		$	1,648		$	1,665
	Due after one year through five years	10,687			11,304			13,603			14,442
	Due after five years through ten years	10,586			10,901			8,726			9,555
	Due after ten years	15,338			16,510			14,164			16,942
	Total	$	39,086		$	41,231		$	38,141		$	42,604

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Summary of Derivative Instruments [Abstract]
Summary of aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments	Derivative Financial Instruments
	September 30, 2013	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Credit default swaps - purchased protection	$	20	$	—	$	—
	Currency forwards	27		—		(1		)
	Equity warrants	5		—		—
	Total without hedge designation	52		—		(1		)
	Trading activities
	Futures sold, not yet purchased	17		—		—
	Total	$	69	$	—	$	(1	)
	December 31, 2012	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Credit default swaps - purchased protection	$	20	$	—	$	(1	)
	Currency forwards	59		—		(2		)
	Equity warrants	5		—		—
	Total	$	84	$	—	$	(3	)

Fair_Value_Tables

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]
Assets and liabilities measured at fair value on a recurring basis	Assets and liabilities measured at fair value on a recurring basis are summarized below.
	September 30, 2013									Total
										Assets/(Liabilities)
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	27	$	20,945		$	211		$	21,183
	States, municipalities and political subdivisions	—		11,364			95			11,459
	Asset-backed:
	Residential mortgage-backed	—		4,449			370			4,819
	Commercial mortgage-backed	—		1,860			157			2,017
	Other asset-backed	—		523			433			956
	Total asset-backed	—		6,832			960			7,792
	U.S. Treasury and obligations of government-sponsored enterprises	144		29			—			173
	Foreign government	81		480			—			561
	Redeemable preferred stock	48		58			—			106
	Total fixed maturity securities	300		39,708			1,266			41,274
	Equity securities	135		51			13			199
	Other invested assets	—		55			—			55
	Short term investments	992		430			—			1,422
	Life settlement contracts, included in Other assets	—		—			90			90
	Separate account business	12		199			2			213
	Total assets	$	1,439	$	40,443		$	1,371		$	43,253
	Liabilities
	Derivative financial instruments, included in Other liabilities	$	—	$	(1	)	$	—		$	(1	)
	Total liabilities	$	—	$	(1	)	$	—		$	(1	)
	December 31, 2012									Total
										Assets/(Liabilities)
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	6	$	22,011		$	219		$	22,236
	States, municipalities and political subdivisions	—		10,687			96			10,783
	Asset-backed:
	Residential mortgage-backed	—		5,507			413			5,920
	Commercial mortgage-backed	—		1,693			129			1,822
	Other asset-backed	—		584			368			952
	Total asset-backed	—		7,784			910			8,694
	U.S. Treasury and obligations of government-sponsored enterprises	158		24			—			182
	Foreign government	140		473			—			613
	Redeemable preferred stock	40		59			26			125
	Total fixed maturity securities	344		41,038			1,251			42,633
	Equity securities	117		98			34			249
	Other invested assets	—		58			1			59
	Short term investments	987		799			6			1,792
	Life settlement contracts, included in Other assets	—		—			100			100
	Separate account business	4		306			2			312
	Total assets	$	1,452	$	42,299		$	1,394		$	45,145
	Liabilities
	Derivative financial instruments, included in Other liabilities	$	—	$	(2	)	$	(1	)	$	(3	)
	Total liabilities	$	—	$	(2	)	$	(1	)	$	(3	)
Table of reconciliation for assets and liablities measured at fair value on a recurring basis using significant unobservable inputs	The tables below present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended September 30, 2013 and 2012.
	Level 3	Balance at		Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at		Unrealized gains (losses) on Level 3 assets and liabilities held at September 30, 2013 recognized in net income (loss)*
	(In millions)	July 1,																	Level 3		of Level 3			September 30,
		2013																						2013
	Fixed maturity securities:
	Corporate and other bonds	$	202	$	1		$	—		$	6		$	(6	)	$	(8	)	$	17	$	(1	)	$	211	$	—
	States, municipalities and political subdivisions	140		—			(3		)	—			—			(15		)	—		(27		)	95		—
	Asset-backed:
	Residential mortgage-backed	428		—			(20		)	5			—			(21		)	—		(22		)	370		(1		)
	Commercial mortgage-backed	165		(1		)	(2		)	10			—			(1		)	—		(14		)	157		—
	Other asset-backed	387		—			1			56			—			(6		)	—		(5		)	433		(1		)
	Total asset-backed	980		(1		)	(21		)	71			—			(28		)	—		(41		)	960		(2		)
	Redeemable preferred stock	25		(1		)	1			—			—			(25		)	—		—			—		—
	Total fixed maturity securities	1,347		(1		)	(23		)	77			(6		)	(76		)	17		(69		)	1,266		(2		)
	Equity securities	13		(2		)	2			—			—			—			—		—			13		(2		)
	Life settlement contracts	91		3			—			—			—			(4		)	—		—			90		—
	Separate account business	2		—			—			—			—			—			—		—			2		—
	Total	$	1,453	$	—		$	(21	)	$	77		$	(6	)	$	(80	)	$	17	$	(69	)	$	1,371	$	(4	)
	Level 3	Balance at		Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at		Unrealized gains (losses) on Level 3 assets and liabilities held at September 30, 2012 recognized in net income (loss)*
	(In millions)	July 1,																	Level 3		of Level 3			September 30,
		2012																						2012
	Fixed maturity securities:
	Corporate and other bonds	$	488	$	1		$	(4	)	$	50		$	(5	)	$	(11	)	$	—	$	(260	)	$	259	$	(1	)
	States, municipalities and political subdivisions	89		—			—			—			—			—			—		—			89		—
	Asset-backed:
	Residential mortgage-backed	443		(17		)	20			21			—			(8		)	—		(22		)	437		(18		)
	Commercial mortgage-backed	166		4			6			12			—			(17		)	11		(65		)	117		—
	Other asset-backed	434		2			5			143			(117		)	(34		)	—		(62		)	371		—
	Total asset-backed	1,043		(11		)	31			176			(117		)	(59		)	11		(149		)	925		(18		)
	Redeemable preferred stock	27		—			(1		)	—			—			—			—		—			26		—
	Total fixed maturity securities	1,647		(10		)	26			226			(122		)	(70		)	11		(409		)	1,299		(19		)
	Equity securities	93		(19		)	(10		)	—			—			—			—		(14		)	50		(19		)
	Other invested assets, including derivatives, net	10		—			—			—			—			—			—		—			10		—
	Short term investments	4		—			—			7			(4		)	—			1		—			8		—
	Life settlement contracts	116		7			—			—			—			(10		)	—		—			113		—
	Separate account business	3		—			—			—			—			—			—		—			3		—
	Total	$	1,873	$	(22	)	$	16		$	233		$	(126	)	$	(80	)	$	12	$	(423	)	$	1,483	$	(38	)
	The tables below present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the nine months ended September 30, 2013 and 2012.
	Level 3	Balance at		Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at		Unrealized gains (losses) on Level 3 assets and liabilities held at September 30, 2013 recognized in net income (loss)*
	(In millions)	January 1,																	Level 3		of Level 3			September 30,
		2013																						2013
	Fixed maturity securities:
	Corporate and other bonds	$	219	$	2		$	(1	)	$	129		$	(96	)	$	(34	)	$	43	$	(51	)	$	211	$	(2	)
	States, municipalities and political subdivisions	96		(3		)	1			122			(79		)	(20		)	5		(27		)	95		—
	Asset-backed:
	Residential mortgage-backed	413		2			(21		)	116			(10		)	(53		)	4		(81		)	370		(3		)
	Commercial mortgage-backed	129		—			7			88			—			(10		)	21		(78		)	157		—
	Other asset-backed	368		3			(1		)	230			(132		)	(30		)	—		(5		)	433		(2		)
	Total asset-backed	910		5			(15		)	434			(142		)	(93		)	25		(164		)	960		(5		)
	Redeemable preferred stock	26		(1		)	—			—			—			(25		)	—		—			—		—
	Total fixed maturity securities	1,251		3			(15		)	685			(317		)	(172		)	73		(242		)	1,266		(7		)
	Equity securities	34		(22		)	2			—			—			—			—		(1		)	13		(22		)
	Other invested assets, including derivatives, net	—		—			—			—			(1		)	1			—		—			—		—
	Short term investments	6		—			—			—			(6		)	—			—		—			—		—
	Life settlement contracts	100		14			—			—			—			(24		)	—		—			90		(1		)
	Separate account business	2		—			—			—			—			—			—		—			2		—
	Total	$	1,393	$	(5	)	$	(13	)	$	685		$	(324	)	$	(195	)	$	73	$	(243	)	$	1,371	$	(30	)
	Level 3	Balance at		Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at		Unrealized gains (losses) on Level 3 assets and liabilities held at September 30, 2012 recognized in net income (loss)*
	(In millions)	January 1,																	Level 3		of Level 3			September 30,
		2012																						2012
	Fixed maturity securities:
	Corporate and other bonds	$	482	$	7		$	2		$	197		$	(118	)	$	(43	)	$	42	$	(310	)	$	259	$	(1	)
	States, municipalities and political subdivisions	171		—			3			—			—			(85		)	—		—			89		—
	Asset-backed:
Residential mortgage-backed	452		(15		)	(2		)	81			—			(24		)	—		(55		)	437		(18		)
Commercial mortgage-backed	59		6			14			141			(12		)	(21		)	11		(81		)	117		—
Other asset-backed	343		8			8			501			(293		)	(93		)	—		(103		)	371		—
Total asset-backed	854		(1		)	20			723			(305		)	(138		)	11		(239		)	925		(18		)
Redeemable preferred stock	—		—			(1		)	53			(26		)	—			—		—			26		—
Total fixed maturity securities	1,507		6			24			973			(449		)	(266		)	53		(549		)	1,299		(19		)
Equity securities	67		(19		)	6			26			(16		)	—			—		(14		)	50		(21		)
Other invested assets, including derivatives, net	10		—			—			—			—			—			—		—			10		—
Short term investments	27		—			—			23			(4		)	(39		)	1		—			8		—
Life settlement contracts	117		30			—			—			—			(34		)	—		—			113		3
Separate account business	23		—			—			—			(20		)	—			—		—			3		—
Total	$	1,751	$	17		$	30		$	1,022		$	(489	)	$	(339	)	$	54	$	(563	)	$	1,483	$	(37	)
Quantitative information about significant unobservable inputs in the fair value measurement of level 3 assets	The table below presents quantitative information about the significant unobservable inputs utilized by the Company in the fair value measurements of Level 3 assets. Valuations for assets and liabilities not presented in the table below are primarily based 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 the Company.
	Assets	Fair Value at September 30, 2013		Valuation Technique(s)		Unobservable Input(s)	Range
	(In millions)						(Weighted Average)
	Fixed maturity securities	$	179	Discounted cash flow		Expected call date	2.1 - 5.3 years (3.8 years)
						Credit spread	1.92% - 26.24% (3.80%)
	Equity securities	$	13	Market approach		Private offering price	$289.80 - $4,273.77 per share
							($1,337.14 per share)
	Life settlement contracts	$	90	Discounted cash flow		Discount rate risk premium	9%
						Mortality assumption	69% - 883% (208.8%)
	Assets	Fair Value at December 31, 2012		Valuation Technique(s)		Unobservable Input(s)	Range
	(In millions)						(Weighted Average)
	Fixed maturity securities	$	121	Discounted cash flow		Expected call date	3.3 - 5.3 years (4.3 years)
						Credit spread adjustment	0.02% - 0.48% (0.17%)
		$	72	Market approach		Private offering price	$42.39 - $102.32 ($100.11)
	Equity securities	$	34	Market approach		Private offering price	$4.54 - $3,842.00 per share
							($571.17 per share)
	Life settlement contracts	$	100	Discounted cash flow		Discount rate risk premium	9%
						Mortality assumption	69% - 883% (208.9%)
Carrying amount and estimated fair value of financial instrument assets and liabilities not measured at fair value	The carrying amount and estimated fair value of the Company's financial instrument assets and liabilities which are not measured at fair value on the Condensed Consolidated Balance Sheets are listed in the tables below.
	September 30, 2013	Carrying		Estimated Fair Value
	(In millions)	Amount		Level 1			Level 2			Level 3			Total
	Financial assets
	Notes receivable for the issuance of common stock	$	22	$	—		$	—		$	22		$	22
	Mortgage loans	440		—			—			452			452
	Financial liabilities
	Premium deposits and annuity contracts	$	68	$	—		$	—		$	69		$	69
	Long term debt	2,559		—			2,928			—			2,928
	31-Dec-12	Carrying		Estimated Fair Value
	(In millions)	Amount		Level 1			Level 2			Level 3			Total
	Financial assets
	Notes receivable for the issuance of common stock	$	21	$	—		$	—		$	21		$	21
	Mortgage loans	401		—			—			418			418
	Financial liabilities
	Premium deposits and annuity contracts	$	100	$	—		$	—		$	104		$	104
	Short term debt	13		—			13			—			13
	Long term debt	2,557		—			3,016			—			3,016

Claim_and_Claim_Adjustment_Exp1

Claim and Claim Adjustment Expense Reserves (Tables)	9 Months Ended
	Sep. 30, 2013
Claim and Claim Adjustment Expense Reserves [Abstract]
Net prior year development	Net Prior Year Development
	Three months ended September 30, 2013
	(In millions)	CNA Specialty			CNA Commercial			Hardy			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(74	)	$	(3	)	$	(6	)	$	2		$	(81	)
	Pretax (favorable) unfavorable premium development	(3		)	7			1			—			5
	Total pretax (favorable) unfavorable net prior year development	$	(77	)	$	4		$	(5	)	$	2		$	(76	)
	Three months ended September 30, 2012
	(In millions)	CNA Specialty			CNA Commercial			Hardy			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(39	)	$	2		$	(6	)	$	3		$	(40	)
	Pretax (favorable) unfavorable premium development	(1		)	(5		)	—			(1		)	(7		)
	Total pretax (favorable) unfavorable net prior year development	$	(40	)	$	(3	)	$	(6	)	$	2		$	(47	)
	Nine months ended September 30, 2013
	(In millions)	CNA Specialty			CNA Commercial			Hardy			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(130	)	$	13		$	5		$	—		$	(112	)
	Pretax (favorable) unfavorable premium development	(16		)	(8		)	7			1			(16		)
	Total pretax (favorable) unfavorable net prior year development	$	(146	)	$	5		$	12		$	1		$	(128	)
	Nine months ended September 30, 2012
	(In millions)	CNA Specialty			CNA Commercial			Hardy			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(80	)	$	(25	)	$	(6	)	$	1		$	(110	)
	Pretax (favorable) unfavorable premium development	(15		)	(41		)	—			1			(55		)
	Total pretax (favorable) unfavorable net prior year development	$	(95	)	$	(66	)	$	(6	)	$	2		$	(165	)
Net prior year claim and allocated claim adjustment expense reserve development for CNA Specialty segment	The following table provides further detail of the net prior year claim and allocated claim adjustment expense reserve development (development) recorded for the CNA Specialty segment for the three and nine months ended September 30, 2013 and 2012.
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Medical Professional Liability	$	9		$	9		$	(11	)	$	(6	)
	Other Professional Liability	(4		)	1			(28		)	(1		)
	Surety	(76		)	(60		)	(74		)	(59		)
	Warranty	—			—			—			(1		)
	Other	(3		)	11			(17		)	(13		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(74	)	$	(39	)	$	(130	)	$	(80	)
Net prior year claim and allocated claim adjustment expense reserve development for CNA Commercial segment	The following table provides further detail of the development recorded for the CNA Commercial segment for the three and nine months ended September 30, 2013 and 2012.
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Commercial Auto	$	4		$	9		$	1		$	11
	General Liability	(18		)	(21		)	(24		)	(26		)
	Workers’ Compensation	26			24			96			13
	Property and Other	(15		)	(10		)	(60		)	(23		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(3	)	$	2		$	13		$	(25	)
Net prior year claim and allocated claim adjustment expense reserve development for Hardy segment	The following table provides further detail of the development recorded for the Hardy segment for the three and nine months ended September 30, 2013 and 2012.
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Marine and Aviation	$	—		$	1		$	3		$	1
	Non-Marine Property	1			(5		)	8			(5		)
	Property Treaty	(5		)	—			(3		)	—
	Specialty	(2		)	(2		)	(3		)	(2		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(6	)	$	(6	)	$	5		$	(6	)

Benefit_Plans_Tables

Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2013
Compensation and Retirement Disclosure [Abstract]
Components of net periodic cost (benefit)	Net Periodic Cost (Benefit)
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	Pension cost (benefit)
	Service cost	$	3		$	3		$	9		$	9
	Interest cost on projected benefit obligation	30			34			90			101
	Expected return on plan assets	(45		)	(43		)	(135		)	(128		)
	Amortization of net actuarial (gain) loss	10			10			34			29
	Settlement loss	3			—			3			—
	Net periodic pension cost (benefit)	$	1		$	4		$	1		$	11
	Postretirement cost (benefit)
	Interest cost on projected benefit obligation	$	—		$	1		$	1		$	2
	Amortization of prior service credit	(4		)	(4		)	(13		)	(13		)
	Amortization of net actuarial (gain) loss	1			—			1			—
	Net periodic postretirement cost (benefit)	$	(3	)	$	(3	)	$	(11	)	$	(11	)

Other_Intangible_Assets_Tables

Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Other Intangible Assets [Abstract]
Schedule of other intangible assets	Other intangible assets are presented in the following table.
		30-Sep-13				31-Dec-12
	(In millions)	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
	Finite-lived intangible assets:
	Value of business acquired	$	62	$	62	$	62	$	43
	Trade name	8		1		8		—
	Distribution channel	13		1		13		—
	Total finite-lived intangible assets	83		64		83		43
	Indefinite-lived intangible assets	73				73
	Total other intangible assets	$	156	$	64	$	156	$	43

Business_Segments_Tables

Business Segments (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]
Significant components of the Company's continuing operations and selected balance sheet items
	Three months ended September 30, 2013	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	768		$	832		$	86		$	140		$	—		$	(1	)	$	1,825
	Net investment income	159			219			1			209			9			—			597
	Other revenues	67			10			1			(3		)	3			—			78
	Total operating revenues	994			1,061			88			346			12			(1		)	2,500
	Claims, Benefits and Expenses
	Net incurred claims and benefits	427			565			35			377			4			—			1,408
	Policyholders’ dividends	3			1			—			2			—			—			6
	Amortization of deferred acquisition costs	161			148			25			7			—			—			341
	Other insurance related expenses	64			141			14			34			1			(1		)	253
	Other expenses	58			7			2			5			49			—			121
	Total claims, benefits and expenses	713			862			76			425			54			(1		)	2,129
	Operating income (loss) before income tax	281			199			12			(79		)	(42		)	—			371
	Income tax (expense) benefit on operating income (loss)	(94		)	(68		)	—			44			16			—			(102		)
	Net operating income (loss)	187			131			12			(35		)	(26		)	—			269
	Net realized investment gains (losses), pre-tax	2			1			—			—			1			—			4
	Income tax (expense) benefit on net realized investment gains (losses)	(1		)	—			1			—			(1		)	—			(1		)
	Net realized investment gains (losses)	1			1			1			—			—			—			3
	Net income (loss)	$	188		$	132		$	13		$	(35	)	$	(26	)	$	—		$	272
	Three months ended September 30, 2012	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	738		$	840		$	64		$	141		$	(2	)	$	—		$	1,781
	Net investment income	159			230			2			201			9			—			601
	Other revenues	58			11			—			1			7			(1		)	76
	Total operating revenues	955			1,081			66			343			14			(1		)	2,458
	Claims, Benefits and Expenses
	Net incurred claims and benefits	460			591			21			350			8			—			1,430
	Policyholders’ dividends	1			3			—			1			—			—			5
	Amortization of deferred acquisition costs	156			151			20			6			—			—			333
	Other insurance related expenses	73			146			13			35			1			—			268
	Other expenses	53			7			7			8			42			(1		)	116
	Total claims, benefits and expenses	743			898			61			400			51			(1		)	2,152
	Operating income (loss) before income tax	212			183			5			(57		)	(37		)	—			306
	Income tax (expense) benefit on operating income (loss)	(76		)	(58		)	(2		)	35			11			—			(90		)
	Net operating income (loss)	136			125			3			(22		)	(26		)	—			216
	Net realized investment gains (losses), pre-tax	2			10			(1		)	(3		)	—			—			8
	Income tax (expense) benefit on net realized investment gains (losses)	(2		)	(3		)	—			1			1			—			(3		)
	Net realized investment gains (losses)	—			7			(1		)	(2		)	1			—			5
	Net income (loss)	$	136		$	132		$	2		$	(24	)	$	(25	)	$	—		$	221
	Nine months ended September 30, 2013	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	2,237		$	2,509		$	226		$	419		$	—		$	(2	)	$	5,389
	Net investment income	480			680			3			620			25			—			1,808
	Other revenues	190			85			1			2			8			(1		)	285
	Total operating revenues	2,907			3,274			230			1,041			33			(3		)	7,482
	Claims, Benefits and Expenses
	Net incurred claims and benefits	1,344			1,809			107			1,082			6			—			4,348
	Policyholders’ dividends	5			5			—			6			—			—			16
	Amortization of deferred acquisition costs	467			450			66			21			—			—			1,004
	Other insurance related expenses	200			426			43			100			1			(2		)	768
	Other expenses	172			18			15			12			134			(1		)	350
	Total claims, benefits and expenses	2,188			2,708			231			1,221			141			(3		)	6,486
	Operating income (loss) before income tax	719			566			(1		)	(180		)	(108		)	—			996
	Income tax (expense) benefit on operating income (loss)	(244		)	(198		)	3			109			38			—			(292		)
	Net operating income (loss)	475			368			2			(71		)	(70		)	—			704
	Net realized investment gains (losses), pre-tax	(1		)	(7		)	2			14			10			—			18
Income tax (expense) benefit on net realized investment gains (losses)	—			3			—			(5		)	(4		)	—			(6		)
Net realized investment gains (losses)	(1		)	(4		)	2			9			6			—			12
Net income (loss)	$	474		$	364		$	4		$	(62	)	$	(64	)	$	—		$	716
September 30, 2013
(In millions)
Reinsurance receivables	$	613		$	1,107		$	227		$	1,229		$	2,627		$	—		$	5,803
Insurance receivables	$	746		$	1,112		$	211		$	10		$	4		$	—		$	2,083
Deferred acquisition costs	$	320		$	270		$	52		$	—		$	—		$	—		$	642
Goodwill	$	117		$	—		$	37		$	—		$	—		$	—		$	154
Insurance reserves
Claim and claim adjustment expenses	$	6,846		$	10,763		$	432		$	3,050		$	2,871		$	—		$	23,962
Unearned premiums	1,811			1,604			274			132			—			(1		)	3,820
Future policy benefits	—			—			—			10,681			—			—			10,681
Policyholders’ funds	10			15			—			102			—			—			127
Nine months ended September 30, 2012	CNA			CNA			Hardy (a)			Life &			Corporate
	Specialty			Commercial						Group			& Other
(In millions)										Non-Core			Non-Core			Eliminations			Total
Operating revenues
Net earned premiums	$	2,163		$	2,452		$	64		$	421		$	(1	)	$	(1	)	$	5,098
Net investment income	446			646			2			600			25			—			1,719
Other revenues	171			31			—			15			14			(1		)	230
Total operating revenues	2,780			3,129			66			1,036			38			(2		)	7,047
Claims, Benefits and Expenses
Net incurred claims and benefits	1,376			1,749			21			1,009			(5		)	—			4,150
Policyholders’ dividends	—			9			—			5			—			—			14
Amortization of deferred acquisition costs	458			437			20			22			—			—			937
Other insurance related expenses	222			425			13			106			1			(1		)	766
Other expenses	153			24			7			18			137			(1		)	338
Total claims, benefits and expenses	2,209			2,644			61			1,160			133			(2		)	6,205
Operating income (loss) before income tax	571			485			5			(124		)	(95		)	—			842
Income tax (expense) benefit on operating income (loss)	(197		)	(164		)	(2		)	86			29			—			(248		)
Net operating income (loss)	374			321			3			(38		)	(66		)	—			594
Net realized investment gains (losses), pre-tax	18			34			(1		)	14			1			—			66
Income tax (expense) benefit on net realized investment gains (losses)	(6		)	(12		)	—			(5		)	—			—			(23		)
Net realized investment gains (losses)	12			22			(1		)	9			1			—			43
Net income (loss)	$	386		$	343		$	2		$	(29	)	$	(65	)	$	—		$	637
December 31, 2012
(In millions)
Reinsurance receivables	$	665		$	1,155		$	294		$	1,273		$	2,844		$	—		$	6,231
Insurance receivables	$	673		$	1,116		$	181		$	9		$	4		$	—		$	1,983
Deferred acquisition costs	$	300		$	269		$	29		$	—		$	—		$	—		$	598
Goodwill	$	117		$	—		$	37		$	—		$	—		$	—		$	154
Insurance reserves
Claim and claim adjustment expenses	$	6,748		$	11,326		$	521		$	3,006		$	3,162		$	—		$	24,763
Unearned premiums	1,685			1,569			222			134			—			—			3,610
Future policy benefits	—			—			—			11,475			—			—			11,475
Policyholders’ funds	8			15			—			134			—			—			157
_______________________________
(a)	Included from date of acquisition.
Revenues by line of business	Revenues by Line of Business
	Periods ended September 30	Three Months						Nine Months
	(In millions)	2013			2012			2013			2012
	CNA Specialty
	International	$	59		$	53		$	177		$	163
	Professional & Management Liability	720			700			2,107			2,039
	Surety	126			124			365			364
	Warranty & Alternative Risks	91			80			257			232
	CNA Specialty revenues	996			957			2,906			2,798
	CNA Commercial
	Commercial Insurance	776			826			2,429			2,396
	International	93			93			276			274
	Small Business	193			172			562			493
	CNA Commercial revenues	1,062			1,091			3,267			3,163
	Hardy revenues	88			65			232			65
	Life & Group Non-Core
	Health	290			274			875			852
	Life & Annuity	58			64			177			181
	Other	(2		)	2			3			17
	Life & Group Non-Core revenues	346			340			1,055			1,050
	Corporate & Other Non-Core revenues	13			14			43			39
	Eliminations	(1		)	(1		)	(3		)	(2		)
	Total revenues	$	2,504		$	2,466		$	7,500		$	7,113

Changes_in_Accumulated_Other_C1

Changes in Accumulated Other Comprehensive Income (Loss) by Component (Tables)	9 Months Ended
	Sep. 30, 2013
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Abstract]
Changes in Accumulated Other Comprehensive Income (Loss) by Component	Changes in Accumulated Other Comprehensive Income (Loss)
	(In millions)	Net unrealized gains (losses) on investments with OTTI losses			Net unrealized gains (losses) on other investments			Pension and postretirement benefits			Cumulative foreign currency translation adjustment			Total
	Balance at June 30, 2013	$	26		$	724		$	(711	)	$	87		$	126
	Other comprehensive income (loss) before reclassifications	(4		)	(68		)	—			56			(16		)
	Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(2), $3, $0, and $1	(1		)	2			(4		)	—			(3		)
	Other comprehensive income (loss) after tax (expense) benefit of $1, $38, $(3), $0, and $36	(3		)	(70		)	4			56			(13		)
	Balance at September 30, 2013	$	23		$	654		$	(707	)	$	143		$	113
	(In millions)	Net unrealized gains (losses) on investments with OTTI losses			Net unrealized gains (losses) on other investments			Pension and postretirement benefits			Cumulative foreign currency translation adjustment			Total
	Balance at January 1, 2013	$	20		$	1,371		$	(721	)	$	161		$	831
	Other comprehensive income (loss) before reclassifications	2			(706		)	—			(18		)	(722		)
	Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(5), $8, $0, and $3	(1		)	11			(14		)	—			(4		)
	Other comprehensive income (loss) after tax (expense) benefit of $(2), $387, $(8), $0, and $377	3			(717		)	14			(18		)	(718		)
	Balance at September 30, 2013	$	23		$	654		$	(707	)	$	143		$	113

General_Narrative_Details

General (Narrative) (Details)	Sep. 30, 2013
Percentage owned of outstanding common stock by majority shareholder	90.00%

Earnings_loss_per_share_Narrat

Earnings (loss) per share (Narrative) (Details)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]
Incremental Common Shares Attributable to Share-based Payment Arrangements	515	450	501	400
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	110	693	115	740

Investments_Narrative_Details

Investments (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Investments [Abstract]
Net unrealized gains (losses) related to changes in fair value of trading securities still held included in net investment income
Reduction of net unrealized gains on investments included in AOCI due to shadow adjustments	723		723		1,511
Pretax net realized gains (losses) on other available-for-sale securities reclassified out of AOCI and recognized in earnings	3	12	15	59
Future capital call commitments for limited partnership investments	405		405
Commitments to purchase or fund privately placed debt securities	172		172
Commitments to sell various privately placed debt securities	$143		$143

Investments_Net_investment_inc

Investments (Net investment income) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Gross investment income	$611	$614	$1,848	$1,761
Investment expense	-14	-13	-40	-42
Net investment income	597	601	1,808	1,719
Fixed maturity securities [Member]
Gross investment income	504	507	1,501	1,528
Short term investments [Member]
Gross investment income	1	2	3	5
Limited partnership investments [Member]
Gross investment income	93	89	303	184
Equity securities [Member]
Gross investment income	3	4	9	10
Mortgage loans [Member]
Gross investment income	6	5	17	13
Trading portfolio [Member]
Gross investment income	3	7	13	18
Other [Member]
Gross investment income	$1		$2	$3

Investments_Net_realized_inves

Investments (Net realized investment gains (losses)) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net realized investment gains (losses)	$4	$8	$18	$66
Fixed maturity securities [Member]
Gross realized gains	51	75	132	193
Gross realized losses	-44	-49	-98	-120
Net realized investment gains (losses)	7	26	34	73
Equity securities [Member]
Gross realized gains	3	5	10	10
Gross realized losses	-5	-20	-27	-24
Net realized investment gains (losses)	-2	-15	-17	-14
Derivatives [Member]
Net realized investment gains (losses)	-1	-1	-4	-1
Short term investments and other [Member]
Net realized investment gains (losses)		($2)	$5	$8

Investments_Components_of_net_

Investments (Components of net other-than-temporary impairment losses recognized in earnings) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net other-than-temporary impairment losses recognized in earnings	$17	$64	$51	$114
Corporate and other bonds [Member]
Net other-than-temporary impairment losses recognized in earnings	9	7	17	23
States, municipalities and political subdivisions [Member]
Net other-than-temporary impairment losses recognized in earnings		17		17
Residential mortgage-backed [Member]
Net other-than-temporary impairment losses recognized in earnings	2	20	5	49
Other asset-backed [Member]
Net other-than-temporary impairment losses recognized in earnings	1		2
Total asset-backed [Member]
Net other-than-temporary impairment losses recognized in earnings	3	20	7	49
U.S. Treasury and obligations of government-sponsored enterprises [Member]
Net other-than-temporary impairment losses recognized in earnings				1
Total fixed maturity securities available-for-sale [Member]
Net other-than-temporary impairment losses recognized in earnings	12	44	24	90
Common stock [Member]
Net other-than-temporary impairment losses recognized in earnings	3	1	5	5
Preferred stock [Member]
Net other-than-temporary impairment losses recognized in earnings	2	19	22	19
Total equity securities available-for-sale [Member]
Net other-than-temporary impairment losses recognized in earnings	$5	$20	$27	$24

Investments_Summary_of_fixed_m

Investments (Summary of fixed maturity and equity securities) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Cost or Amortized Cost	$39,318	$38,398
Gross Unrealized Gains	2,673	4,639
Gross Unrealized Losses	518	155
Estimated Fair Value	41,473	42,882
Corporate and other bonds [Member]
Cost or Amortized Cost	19,616	19,530
Gross Unrealized Gains	1,695	2,698
Gross Unrealized Losses	151	21
Estimated Fair Value	21,160	22,207
Unrealized OTTI Losses (Gains)
States, municipalities and political subdivisions [Member]
Cost or Amortized Cost	11,000	9,372
Gross Unrealized Gains	672	1,455
Gross Unrealized Losses	233	44
Estimated Fair Value	11,439	10,783
Unrealized OTTI Losses (Gains)
Residential mortgage-backed [Member]
Cost or Amortized Cost	4,779	5,745
Gross Unrealized Gains	141	246
Gross Unrealized Losses	101	71
Estimated Fair Value	4,819	5,920
Unrealized OTTI Losses (Gains)	-33	-28
Commercial mortgage-backed [Member]
Cost or Amortized Cost	1,942	1,692
Gross Unrealized Gains	99	147
Gross Unrealized Losses	24	17
Estimated Fair Value	2,017	1,822
Unrealized OTTI Losses (Gains)	-3	-3
Other asset-backed [Member]
Cost or Amortized Cost	942	929
Gross Unrealized Gains	16	23
Gross Unrealized Losses	2
Estimated Fair Value	956	952
Unrealized OTTI Losses (Gains)
Total asset-backed [Member]
Cost or Amortized Cost	7,663	8,366
Gross Unrealized Gains	256	416
Gross Unrealized Losses	127	88
Estimated Fair Value	7,792	8,694
Unrealized OTTI Losses (Gains)	-36	-31
U.S. Treasury and obligations of government-sponsored enterprises [Member]
Cost or Amortized Cost	166	172
Gross Unrealized Gains	8	11
Gross Unrealized Losses	1	1
Estimated Fair Value	173	182
Unrealized OTTI Losses (Gains)
Foreign government [Member]
Cost or Amortized Cost	547	588
Gross Unrealized Gains	17	25
Gross Unrealized Losses	3
Estimated Fair Value	561	613
Unrealized OTTI Losses (Gains)
Redeemable preferred stock [Member]
Cost or Amortized Cost	94	113
Gross Unrealized Gains	12	13
Gross Unrealized Losses		1
Estimated Fair Value	106	125
Unrealized OTTI Losses (Gains)
Total fixed maturity securities available-for-sale [Member]
Cost or Amortized Cost	39,086	38,141
Gross Unrealized Gains	2,660	4,618
Gross Unrealized Losses	515	155
Estimated Fair Value	41,231	42,604
Unrealized OTTI Losses (Gains)	-36	-31
Total fixed maturity securities trading [Member]
Cost or Amortized Cost, Trading Securities	43	29
Gross Unrealized Gains, Trading Securities
Gross Unrealized Losses, Trading Securities
Estimated Fair Value, Trading Securities	43	29
Common stock [Member]
Cost or Amortized Cost	41	38
Gross Unrealized Gains	12	14
Gross Unrealized Losses
Estimated Fair Value	53	52
Preferred stock [Member]
Cost or Amortized Cost	148	190
Gross Unrealized Gains	1	7
Gross Unrealized Losses	3
Estimated Fair Value	146	197
Total equity securities available-for-sale [Member]
Cost or Amortized Cost	189	228
Gross Unrealized Gains	13	21
Gross Unrealized Losses	3
Estimated Fair Value	$199	$249

Investments_Securities_in_a_gr

Investments (Securities in a gross unrealized loss position) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Estimated Fair Value, Less Than 12 Months	$8,062	$1,819
Gross Unrealized Losses, Less than 12 Months	394	27
Estimated Fair Value, 12 Months or Longer	533	866
Gross Unrealized Losses, 12 Months or Longer	124	128
Estimated Fair Value, Total	8,595	2,685
Gross Unrealized Losses, Total	518	155
Corporate and other bonds [Member]
Estimated Fair Value, Less Than 12 Months	3,521	846
Gross Unrealized Losses, Less than 12 Months	146	13
Estimated Fair Value, 12 Months or Longer	45	108
Gross Unrealized Losses, 12 Months or Longer	5	8
Estimated Fair Value, Total	3,566	954
Gross Unrealized Losses, Total	151	21
States, municipalities and political subdivisions [Member]
Estimated Fair Value, Less Than 12 Months	2,413	254
Gross Unrealized Losses, Less than 12 Months	179	5
Estimated Fair Value, 12 Months or Longer	122	165
Gross Unrealized Losses, 12 Months or Longer	54	39
Estimated Fair Value, Total	2,535	419
Gross Unrealized Losses, Total	233	44
Residential mortgage-backed [Member]
Estimated Fair Value, Less Than 12 Months	1,289	583
Gross Unrealized Losses, Less than 12 Months	40	5
Estimated Fair Value, 12 Months or Longer	287	452
Gross Unrealized Losses, 12 Months or Longer	61	66
Estimated Fair Value, Total	1,576	1,035
Gross Unrealized Losses, Total	101	71
Commercial mortgage-backed [Member]
Estimated Fair Value, Less Than 12 Months	449	85
Gross Unrealized Losses, Less than 12 Months	20	2
Estimated Fair Value, 12 Months or Longer	79	141
Gross Unrealized Losses, 12 Months or Longer	4	15
Estimated Fair Value, Total	528	226
Gross Unrealized Losses, Total	24	17
Other asset-backed [Member]
Estimated Fair Value, Less Than 12 Months	207
Gross Unrealized Losses, Less than 12 Months	2
Estimated Fair Value, 12 Months or Longer
Gross Unrealized Losses, 12 Months or Longer
Estimated Fair Value, Total	207
Gross Unrealized Losses, Total	2
Total asset-backed [Member]
Estimated Fair Value, Less Than 12 Months	1,945	668
Gross Unrealized Losses, Less than 12 Months	62	7
Estimated Fair Value, 12 Months or Longer	366	593
Gross Unrealized Losses, 12 Months or Longer	65	81
Estimated Fair Value, Total	2,311	1,261
Gross Unrealized Losses, Total	127	88
U.S. Treasury and obligations of government-sponsored enterprises [Member]
Estimated Fair Value, Less Than 12 Months	21	23
Gross Unrealized Losses, Less than 12 Months	1	1
Estimated Fair Value, 12 Months or Longer
Gross Unrealized Losses, 12 Months or Longer
Estimated Fair Value, Total	21	23
Gross Unrealized Losses, Total	1	1
Foreign government [Member]
Estimated Fair Value, Less Than 12 Months	76
Gross Unrealized Losses, Less than 12 Months	3
Estimated Fair Value, 12 Months or Longer
Gross Unrealized Losses, 12 Months or Longer
Estimated Fair Value, Total	76
Gross Unrealized Losses, Total	3
Total fixed maturity securities available-for-sale [Member]
Estimated Fair Value, Less Than 12 Months	7,976
Gross Unrealized Losses, Less than 12 Months	391
Estimated Fair Value, 12 Months or Longer	533
Gross Unrealized Losses, 12 Months or Longer	124
Estimated Fair Value, Total	8,509
Gross Unrealized Losses, Total	515
Preferred stock [Member]
Estimated Fair Value, Less Than 12 Months	86
Gross Unrealized Losses, Less than 12 Months	3
Estimated Fair Value, 12 Months or Longer
Gross Unrealized Losses, 12 Months or Longer
Estimated Fair Value, Total	86
Gross Unrealized Losses, Total	3
Redeemable preferred stock [Member]
Estimated Fair Value, Less Than 12 Months		28
Gross Unrealized Losses, Less than 12 Months		1
Estimated Fair Value, 12 Months or Longer
Gross Unrealized Losses, 12 Months or Longer
Estimated Fair Value, Total		28
Gross Unrealized Losses, Total		$1

Investments_Activity_related_t

Investments (Activity related to the pretax fixed maturity credit loss component reflected within retained earnings for securities still held for which a portion of an OTTI loss was recognized in OCI) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance of credit losses on fixed maturity securities	$89	$99	$95	$92
Additional credit losses for securities for which an OTTI loss was previously recognized	1	2	2	23
Credit losses for securities for which an OTTI loss was not previously recognized				2
Reductions for securities sold during the period	-7	-3	-14	-11
Reductions for securities the Company intends to sell or more likely than not will be required to sell				-8
Ending balance of credit losses on fixed maturity securities	$83	$98	$83	$98

Investments_Contractual_maturi

Investments (Contractual maturity) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Cost or Amortized Cost
Due in one year or less	$2,475	$1,648
Due after one year through five years	10,687	13,603
Due after five years through ten years	10,586	8,726
Due after ten years	15,338	14,164
Total	39,086	38,141
Estimated Fair Value
Due in one year or less	2,516	1,665
Due after one year through five years	11,304	14,442
Due after five years through ten years	10,901	9,555
Due after ten years	16,510	16,942
Total	$41,231	$42,604

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative transactions entered into	$224	$472	$2,271	$1,251
Derivative transactions terminated	$221	$488	$2,286	$1,200

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Summary of aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Derivative [Line Items]
Contractual/notional amount	$69	$84
Estimated fair value asset
Estimated fair value (liability)	-1	-3
Derivative Instruments Without Hedge Designation [Member]
Derivative [Line Items]
Contractual/notional amount	52	84
Estimated fair value asset
Estimated fair value (liability)	-1	-3
Derivative Instruments Without Hedge Designation [Member] | Credit default swap - purchased protection [Member]
Derivative [Line Items]
Contractual/notional amount	20	20
Estimated fair value asset
Estimated fair value (liability)		-1
Derivative Instruments Without Hedge Designation [Member] | Currency forwards [Member]
Derivative [Line Items]
Contractual/notional amount	27	59
Estimated fair value asset
Estimated fair value (liability)	-1	-2
Derivative Instruments Without Hedge Designation [Member] | Equity warrants [Member]
Derivative [Line Items]
Contractual/notional amount	5	5
Estimated fair value asset
Estimated fair value (liability)
Trading activities [Member] | Futures Sold, Not yet Purchased [Member]
Derivative [Line Items]
Contractual/notional amount	17
Estimated fair value asset
Estimated fair value (liability)

Fair_Value_Narrative_Details

Fair Value (Narrative) (Details) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount		$106

Fair_Value_Assets_and_liabilit

Fair Value (Assets and liabilities measured at fair value on a recurring basis) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	$41,274	$42,633
Equity securities	199	249
Other invested assets	55	59
Short term investments	1,475	1,832
Separate account business	213	312
Derivative financial instruments, included in Other liabilities	-1	-3
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	41,274	42,633
Equity securities	199	249
Other invested assets	55	59
Short term investments	1,422	1,792
Life settlement contracts, included in Other assets	90	100
Separate account business	213	312
Total assets	43,253	45,145
Derivative financial instruments, included in Other liabilities	-1	-3
Total liabilities	-1	-3
Fair Value, Measurements, Recurring [Member] | Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	21,183	22,236
Fair Value, Measurements, Recurring [Member] | States, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	11,459	10,783
Fair Value, Measurements, Recurring [Member] | Residential mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	4,819	5,920
Fair Value, Measurements, Recurring [Member] | Commercial mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	2,017	1,822
Fair Value, Measurements, Recurring [Member] | Other asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	956	952
Fair Value, Measurements, Recurring [Member] | Total asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	7,792	8,694
Fair Value, Measurements, Recurring [Member] | U.S. Treasury and obligations of government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	173	182
Fair Value, Measurements, Recurring [Member] | Foreign government [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	561	613
Fair Value, Measurements, Recurring [Member] | Redeemable preferred stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	106	125
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	300	344
Equity securities	135	117
Other invested assets
Short term investments	992	987
Life settlement contracts, included in Other assets
Separate account business	12	4
Total assets	1,439	1,452
Derivative financial instruments, included in Other liabilities
Total liabilities
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	27	6
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | States, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Residential mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Commercial mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Other asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Total asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | U.S. Treasury and obligations of government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	144	158
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Foreign government [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	81	140
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Redeemable preferred stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	48	40
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	39,708	41,038
Equity securities	51	98
Other invested assets	55	58
Short term investments	430	799
Life settlement contracts, included in Other assets
Separate account business	199	306
Total assets	40,443	42,299
Derivative financial instruments, included in Other liabilities	-1	-2
Total liabilities	-1	-2
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	20,945	22,011
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | States, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	11,364	10,687
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Residential mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	4,449	5,507
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Commercial mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	1,860	1,693
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Other asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	523	584
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Total asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	6,832	7,784
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | U.S. Treasury and obligations of government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	29	24
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Foreign government [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	480	473
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Redeemable preferred stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	58	59
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	1,266	1,251
Equity securities	13	34
Other invested assets		1
Short term investments		6
Life settlement contracts, included in Other assets	90	100
Separate account business	2	2
Total assets	1,371	1,394
Derivative financial instruments, included in Other liabilities		-1
Total liabilities		-1
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	211	219
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | States, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	95	96
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Residential mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	370	413
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Commercial mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	157	129
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Other asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	433	368
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Total asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities	960	910
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | U.S. Treasury and obligations of government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Foreign government [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Redeemable preferred stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities		$26

Fair_Value_Table_of_reconcilia

Fair Value (Table of reconciliation for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	$1,453	$1,873	$1,393	$1,751
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)		-22	-5	17
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-21	16	-13	30
Purchases	77	233	685	1,022
Sales	-6	-126	-324	-489
Settlements	-80	-80	-195	-339
Transfers into Level 3	17	12	73	54
Transfers out of Level 3	-69	-423	-243	-563
Balance, Ending, Assets	1,371	1,483	1,371	1,483
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-4	-38	-30	-37
Corporate and other bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	202	488	219	482
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	1	1	2	7
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)		-4	-1	2
Purchases	6	50	129	197
Sales	-6	-5	-96	-118
Settlements	-8	-11	-34	-43
Transfers into Level 3	17		43	42
Transfers out of Level 3	-1	-260	-51	-310
Balance, Ending, Assets	211	259	211	259
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)		-1	-2	-1
States, municipalities and political subdivisions [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	140	89	96	171
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)			-3
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-3		1	3
Purchases			122
Sales			-79
Settlements	-15		-20	-85
Transfers into Level 3			5
Transfers out of Level 3	-27		-27
Balance, Ending, Assets	95	89	95	89
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)
Residential mortgage-backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	428	443	413	452
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)		-17	2	-15
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-20	20	-21	-2
Purchases	5	21	116	81
Sales			-10
Settlements	-21	-8	-53	-24
Transfers into Level 3			4
Transfers out of Level 3	-22	-22	-81	-55
Balance, Ending, Assets	370	437	370	437
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-1	-18	-3	-18
Commercial mortgage-backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	165	166	129	59
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	-1	4		6
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-2	6	7	14
Purchases	10	12	88	141
Sales				-12
Settlements	-1	-17	-10	-21
Transfers into Level 3		11	21	11
Transfers out of Level 3	-14	-65	-78	-81
Balance, Ending, Assets	157	117	157	117
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)
Other asset-backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	387	434	368	343
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)		2	3	8
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	1	5	-1	8
Purchases	56	143	230	501
Sales		-117	-132	-293
Settlements	-6	-34	-30	-93
Transfers into Level 3
Transfers out of Level 3	-5	-62	-5	-103
Balance, Ending, Assets	433	371	433	371
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-1		-2
Total asset-backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	980	1,043	910	854
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	-1	-11	5	-1
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-21	31	-15	20
Purchases	71	176	434	723
Sales		-117	-142	-305
Settlements	-28	-59	-93	-138
Transfers into Level 3		11	25	11
Transfers out of Level 3	-41	-149	-164	-239
Balance, Ending, Assets	960	925	960	925
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-2	-18	-5	-18
Redeemable preferred stock [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	25	27	26
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	-1		-1
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	1	-1		-1
Purchases				53
Sales				-26
Settlements	-25		-25
Transfers into Level 3
Transfers out of Level 3
Balance, Ending, Assets		26		26
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)
Fixed maturity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	1,347	1,647	1,251	1,507
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	-1	-10	3	6
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-23	26	-15	24
Purchases	77	226	685	973
Sales	-6	-122	-317	-449
Settlements	-76	-70	-172	-266
Transfers into Level 3	17	11	73	53
Transfers out of Level 3	-69	-409	-242	-549
Balance, Ending, Assets	1,266	1,299	1,266	1,299
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-2	-19	-7	-19
Equity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	13	93	34	67
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	-2	-19	-22	-19
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	2	-10	2	6
Purchases				26
Sales				-16
Settlements
Transfers into Level 3
Transfers out of Level 3		-14	-1	-14
Balance, Ending, Assets	13	50	13	50
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-2	-19	-22	-21
Other invested assets, including derivatives, net
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets		10		10
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)
Purchases
Sales			-1
Settlements			1
Transfers into Level 3
Transfers out of Level 3
Balance, Ending, Assets		10		10
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)
Short term investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets		4	6	27
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)
Purchases		7		23
Sales		-4	-6	-4
Settlements				-39
Transfers into Level 3		1		1
Transfers out of Level 3
Balance, Ending, Assets		8		8
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)
Life settlement contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	91	116	100	117
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	3	7	14	30
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)
Purchases
Sales
Settlements	-4	-10	-24	-34
Transfers into Level 3
Transfers out of Level 3
Balance, Ending, Assets	90	113	90	113
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)			-1	3
Separate account business [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	2	3	2	23
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)
Purchases
Sales				-20
Settlements
Transfers into Level 3
Transfers out of Level 3
Balance, Ending, Assets	2	3	2	3
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)

Fair_Value_Quantitative_inform

Fair Value (Quantitative information about significant unobservable inputs in the fair value measurement of level 3 assets) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, except Per Share data, unless otherwise specified
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	$179	$121
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Expected call date	2.1	3.3
Credit spread adjustment		0.02%
Credit spread	1.92%
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Expected call date	5.3	5.3
Credit spread adjustment		0.48%
Credit spread	26.24%
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Expected call date	3.8	4.3
Credit spread adjustment		0.17%
Credit spread	3.80%
Fixed maturity securities [Member] | Market approach valuation technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure		72
Fixed maturity securities [Member] | Market approach valuation technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price		$42.39
Fixed maturity securities [Member] | Market approach valuation technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price		$102.32
Fixed maturity securities [Member] | Market approach valuation technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price		$100.11
Equity securities [Member] | Market approach valuation technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	13	34
Equity securities [Member] | Market approach valuation technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price	$289.80	$4.54
Equity securities [Member] | Market approach valuation technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price	$4,273.77	$3,842
Equity securities [Member] | Market approach valuation technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price	$1,337.14	$571.17
Life settlement contracts [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	$90	$100
Life settlement contracts [Member] | Income Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality assumption	69.00%	69.00%
Life settlement contracts [Member] | Income Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality assumption	883.00%	883.00%
Life settlement contracts [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality assumption	208.80%	208.90%
Life settlement contracts [Member] | Income Approach Valuation Technique [Member] | Rate [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate risk premium	9.00%	9.00%

Fair_Value_Carrying_amount_and

Fair Value (Carrying amount and estimated fair value of financial instrument assets and liabilities which are not measured at fair value) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	$22	$21
Mortgage loans	440	401
Financial Liabilities [Abstract]
Short term debt		13
Long term debt	2,559	2,557
Carrying Amount [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	22	21
Mortgage loans	440	401
Financial Liabilities [Abstract]
Premium deposits and annuity contracts	68	100
Short term debt		13
Long term debt	2,559	2,557
Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	22	21
Mortgage loans	452	418
Financial Liabilities [Abstract]
Premium deposits and annuity contracts	69	104
Short term debt		13
Long term debt	2,928	3,016
Level 1 [Member] | Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock
Mortgage loans
Financial Liabilities [Abstract]
Premium deposits and annuity contracts
Short term debt
Long term debt
Level 2 [Member] | Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock
Mortgage loans
Financial Liabilities [Abstract]
Premium deposits and annuity contracts
Short term debt		13
Long term debt	2,928	3,016
Level 3 [Member] | Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	22	21
Mortgage loans	452	418
Financial Liabilities [Abstract]
Premium deposits and annuity contracts	69	104
Short term debt
Long term debt

Claim_and_Claim_Adjustment_Exp2

Claim and Claim Adjustment Expense Reserves (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Claim and Claim Adjustment Expense Reserves [Abstract]
Catastrophe losses net of reinsurance	$42	$27	$146	$123

Claim_and_Claim_Adjustment_Exp3

Claim and Claim Adjustment Expense Reserves (Net prior year development) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($81)	($40)	($112)	($110)
Pretax (favorable) unfavorable premium development, excluding Life & Group	5	-7	-16	-55
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-76	-47	-128	-165
CNA Specialty [Member]
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	-74	-39	-130	-80
Pretax (favorable) unfavorable premium development, excluding Life & Group	-3	-1	-16	-15
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-77	-40	-146	-95
CNA Commercial [Member]
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	-3	2	13	-25
Pretax (favorable) unfavorable premium development, excluding Life & Group	7	-5	-8	-41
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	4	-3	5	-66
Hardy [Member]
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	-6	-6	5	-6
Pretax (favorable) unfavorable premium development, excluding Life & Group	1		7
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-5	-6	12	-6
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	2	3		1
Pretax (favorable) unfavorable premium development, excluding Life & Group		-1	1	1
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	$2	$2	$1	$2

Claim_and_Claim_Adjustment_Exp4

Claim and Claim Adjustment Expense Reserves (Net prior year claim and allocated claim adjustment expense reserve development for CNA Specialty segment) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($81)	($40)	($112)	($110)
CNA Specialty [Member]
Medical Professional Liability	9	9	-11	-6
Other Professional Liability	-4	1	-28	-1
Surety	-76	-60	-74	-59
Warranty				-1
Other	-3	11	-17	-13
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($74)	($39)	($130)	($80)

Claim_and_Claim_Adjustment_Exp5

Claim and Claim Adjustment Expense Reserves (Net prior year claim and allocated claim adjustment expense reserve development for CNA Commercial segment) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($81)	($40)	($112)	($110)
CNA Commercial [Member]
Commercial Auto	4	9	1	11
General Liability	-18	-21	-24	-26
Workers' Compensation	26	24	96	13
Property and Other	-15	-10	-60	-23
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($3)	$2	$13	($25)

Claim_and_Claim_Adjustment_Exp6

Claim and Claim Adjustment Expense Reserves (Net prior year claim and allocated claim adjustment expense reserve development for Hardy segment) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($81)	($40)	($112)	($110)
Hardy [Member]
Marine and Aviation		1	3	1
Non-Marine Property	1	-5	8	-5
Property Treaty	-5		-3
Specialty	-2	-2	-3	-2
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($6)	($6)	$5	($6)

Benefit_Plans_Components_of_ne

Benefit Plans (Components of net periodic cost (benefit)) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$3	$3	$9	$9
Interest cost on projected benefit obligation	30	34	90	101
Expected return on plan assets	-45	-43	-135	-128
Amortization of net actuarial (gain) loss	10	10	34	29
Settlement loss	3		3
Net periodic cost (benefit)	1	4	1	11
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on projected benefit obligation		1	1	2
Amortization of prior service credit	-4	-4	-13	-13
Amortization of net actuarial (gain) loss	1		1
Net periodic cost (benefit)	($3)	($3)	($11)	($11)

Other_Intangible_Assets_Schedu

Other Intangible Assets Schedule of Other Intangible Assets (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Amortization of deferred acquisition costs	$341	$333	$1,004	$937
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	1		1
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	4		4
Finite-Lived Intangible Assets, Amortization Expense, Year Two	1		1
Finite-Lived Intangible Assets, Amortization Expense, Year Three	2		2
Finite-Lived Intangible Assets, Amortization Expense, Year Four	2		2
Finite-Lived Intangible Assets, Amortization Expense, Year Five	2		2
Hardy [Member]
Amortization of deferred acquisition costs	25	20	66	20
Other Intangible Assets [Member] | Hardy [Member]
Amortization of deferred acquisition costs	1	18	14	18
Amortization expense included in other operating expenses	($1)	$6	$4	$6

Other_Intangible_Assets_Schedu1

Other Intangible Assets Schedule of Other Intangible Assets (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Finite-lived intangible assets	$83	$83
Accumulated amortization	64	43
Indefinite-lived intangible assets	73	73
Total other intangible assets	156	156
Total intangible assets, accumulated amortization	64	43
Value of business acquired [Member]
Finite-lived intangible assets	62	62
Accumulated amortization	62	43
Trade name [Member]
Finite-lived intangible assets	8	8
Accumulated amortization	1
Distribution channel [Member]
Finite-lived intangible assets	13	13
Accumulated amortization	$1

Commitments_Contingencies_and_1

Commitments, Contingencies, and Guarantees (Narrative) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
Maximum potential future lease payments and other related costs under guarantee on a real estate joint venture	$90
Aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third party loans	723
Recorded liabilities related to indemnification agreements	$7	$7

Business_Segments_Income_State

Business Segments (Income Statement Information) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Operating Revenues
Net earned premiums	$1,825	$1,781	$5,389	$5,098
Net investment income	597	601	1,808	1,719
Other revenues	78	76	285	230
Total operating revenues	2,500	2,458	7,482	7,047
Claims, Benefits and Expenses
Net incurred claims and benefits	1,408	1,430	4,348	4,150
Policyholders' dividends	6	5	16	14
Amortization of deferred acquisition costs	341	333	1,004	937
Other insurance related expenses	253	268	768	766
Other expenses	121	116	350	338
Total claims, benefits and expenses	2,129	2,152	6,486	6,205
Operating income (loss) before income tax	371	306	996	842
Income tax (expense) benefit on operating income (loss)	-102	-90	-292	-248
Net operating income (loss)	269	216	704	594
Net realized investment gains (losses), pre-tax	4	8	18	66
Income tax (expense) benefit on net realized investment gains (losses)	-1	-3	-6	-23
Net realized investment gains (losses)	3	5	12	43
Net income (loss)	272	221	716	637
CNA Specialty [Member]
Operating Revenues
Net earned premiums	768	738	2,237	2,163
Net investment income	159	159	480	446
Other revenues	67	58	190	171
Total operating revenues	994	955	2,907	2,780
Claims, Benefits and Expenses
Net incurred claims and benefits	427	460	1,344	1,376
Policyholders' dividends	3	1	5
Amortization of deferred acquisition costs	161	156	467	458
Other insurance related expenses	64	73	200	222
Other expenses	58	53	172	153
Total claims, benefits and expenses	713	743	2,188	2,209
Operating income (loss) before income tax	281	212	719	571
Income tax (expense) benefit on operating income (loss)	-94	-76	-244	-197
Net operating income (loss)	187	136	475	374
Net realized investment gains (losses), pre-tax	2	2	-1	18
Income tax (expense) benefit on net realized investment gains (losses)	-1	-2		-6
Net realized investment gains (losses)	1		-1	12
Net income (loss)	188	136	474	386
CNA Commercial [Member]
Operating Revenues
Net earned premiums	832	840	2,509	2,452
Net investment income	219	230	680	646
Other revenues	10	11	85	31
Total operating revenues	1,061	1,081	3,274	3,129
Claims, Benefits and Expenses
Net incurred claims and benefits	565	591	1,809	1,749
Policyholders' dividends	1	3	5	9
Amortization of deferred acquisition costs	148	151	450	437
Other insurance related expenses	141	146	426	425
Other expenses	7	7	18	24
Total claims, benefits and expenses	862	898	2,708	2,644
Operating income (loss) before income tax	199	183	566	485
Income tax (expense) benefit on operating income (loss)	-68	-58	-198	-164
Net operating income (loss)	131	125	368	321
Net realized investment gains (losses), pre-tax	1	10	-7	34
Income tax (expense) benefit on net realized investment gains (losses)		-3	3	-12
Net realized investment gains (losses)	1	7	-4	22
Net income (loss)	132	132	364	343
Hardy [Member]
Operating Revenues
Net earned premiums	86	64	226	64
Net investment income	1	2	3	2
Other revenues	1		1
Total operating revenues	88	66	230	66
Claims, Benefits and Expenses
Net incurred claims and benefits	35	21	107	21
Policyholders' dividends
Amortization of deferred acquisition costs	25	20	66	20
Other insurance related expenses	14	13	43	13
Other expenses	2	7	15	7
Total claims, benefits and expenses	76	61	231	61
Operating income (loss) before income tax	12	5	-1	5
Income tax (expense) benefit on operating income (loss)		-2	3	-2
Net operating income (loss)	12	3	2	3
Net realized investment gains (losses), pre-tax		-1	2	-1
Income tax (expense) benefit on net realized investment gains (losses)	1
Net realized investment gains (losses)	1	-1	2	-1
Net income (loss)	13	2	4	2
Life and Group Non-Core [Member]
Operating Revenues
Net earned premiums	140	141	419	421
Net investment income	209	201	620	600
Other revenues	-3	1	2	15
Total operating revenues	346	343	1,041	1,036
Claims, Benefits and Expenses
Net incurred claims and benefits	377	350	1,082	1,009
Policyholders' dividends	2	1	6	5
Amortization of deferred acquisition costs	7	6	21	22
Other insurance related expenses	34	35	100	106
Other expenses	5	8	12	18
Total claims, benefits and expenses	425	400	1,221	1,160
Operating income (loss) before income tax	-79	-57	-180	-124
Income tax (expense) benefit on operating income (loss)	44	35	109	86
Net operating income (loss)	-35	-22	-71	-38
Net realized investment gains (losses), pre-tax		-3	14	14
Income tax (expense) benefit on net realized investment gains (losses)		1	-5	-5
Net realized investment gains (losses)		-2	9	9
Net income (loss)	-35	-24	-62	-29
Corporate and Other Non-Core [Member]
Operating Revenues
Net earned premiums		-2		-1
Net investment income	9	9	25	25
Other revenues	3	7	8	14
Total operating revenues	12	14	33	38
Claims, Benefits and Expenses
Net incurred claims and benefits	4	8	6	-5
Policyholders' dividends
Amortization of deferred acquisition costs
Other insurance related expenses	1	1	1	1
Other expenses	49	42	134	137
Total claims, benefits and expenses	54	51	141	133
Operating income (loss) before income tax	-42	-37	-108	-95
Income tax (expense) benefit on operating income (loss)	16	11	38	29
Net operating income (loss)	-26	-26	-70	-66
Net realized investment gains (losses), pre-tax	1		10	1
Income tax (expense) benefit on net realized investment gains (losses)	-1	1	-4
Net realized investment gains (losses)		1	6	1
Net income (loss)	-26	-25	-64	-65
Eliminations [Member]
Operating Revenues
Net earned premiums	-1		-2	-1
Net investment income
Other revenues		-1	-1	-1
Total operating revenues	-1	-1	-3	-2
Claims, Benefits and Expenses
Net incurred claims and benefits
Policyholders' dividends
Amortization of deferred acquisition costs
Other insurance related expenses	-1		-2	-1
Other expenses		-1	-1	-1
Total claims, benefits and expenses	-1	-1	-3	-2
Operating income (loss) before income tax
Income tax (expense) benefit on operating income (loss)
Net operating income (loss)
Net realized investment gains (losses), pre-tax
Income tax (expense) benefit on net realized investment gains (losses)
Net realized investment gains (losses)
Net income (loss)

Business_Segments_Balance_Shee

Business Segments (Balance Sheet Information) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Segment Reporting Information [Line Items]
Reinsurance receivables	$5,803	$6,231
Insurance receivables	2,083	1,983
Deferred acquisition costs	642	598
Goodwill	154	154
Insurance reserves
Claim and claim adjustment expenses	23,962	24,763
Unearned premiums	3,820	3,610
Future policy benefits	10,681	11,475
Policyholders’ funds	127	157
CNA Specialty [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	613	665
Insurance receivables	746	673
Deferred acquisition costs	320	300
Goodwill	117	117
Insurance reserves
Claim and claim adjustment expenses	6,846	6,748
Unearned premiums	1,811	1,685
Future policy benefits
Policyholders’ funds	10	8
CNA Commercial [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	1,107	1,155
Insurance receivables	1,112	1,116
Deferred acquisition costs	270	269
Goodwill
Insurance reserves
Claim and claim adjustment expenses	10,763	11,326
Unearned premiums	1,604	1,569
Future policy benefits
Policyholders’ funds	15	15
Hardy [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	227	294
Insurance receivables	211	181
Deferred acquisition costs	52	29
Goodwill	37	37
Insurance reserves
Claim and claim adjustment expenses	432	521
Unearned premiums	274	222
Future policy benefits
Policyholders’ funds
Life and Group Non-Core [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	1,229	1,273
Insurance receivables	10	9
Deferred acquisition costs
Goodwill
Insurance reserves
Claim and claim adjustment expenses	3,050	3,006
Unearned premiums	132	134
Future policy benefits	10,681	11,475
Policyholders’ funds	102	134
Corporate and Other Non-Core [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	2,627	2,844
Insurance receivables	4	4
Deferred acquisition costs
Goodwill
Insurance reserves
Claim and claim adjustment expenses	2,871	3,162
Unearned premiums
Future policy benefits
Policyholders’ funds
Eliminations [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables
Insurance receivables
Deferred acquisition costs
Goodwill
Insurance reserves
Claim and claim adjustment expenses
Unearned premiums	-1
Future policy benefits
Policyholders’ funds

Business_Segments_Revenues_by_

Business Segments (Revenues by Line of Business) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues	$2,504	$2,466	$7,500	$7,113
CNA Specialty [Domain]
Revenues	996	957	2,906	2,798
International - Specialty [Member]
Revenues	59	53	177	163
Professional & Management Liability [Member]
Revenues	720	700	2,107	2,039
Surety [Member]
Revenues	126	124	365	364
Warranty & Alternative Risks [Member]
Revenues	91	80	257	232
CNA Commercial [Domain]
Revenues	1,062	1,091	3,267	3,163
Commercial Insurance [Member]
Revenues	776	826	2,429	2,396
International - Commercial [Member]
Revenues	93	93	276	274
Small Business [Member]
Revenues	193	172	562	493
Hardy [Domain]
Revenues	88	65	232	65
Life & Group Non-Core [Domain]
Revenues	346	340	1,055	1,050
Health [Member]
Revenues	290	274	875	852
Life & Annuity [Member]
Revenues	58	64	177	181
Other
Revenues	-2	2	3	17
Corporate and Other Non-Core revenues [Member]
Revenues	13	14	43	39
Eliminations [Member]
Revenues	($1)	($1)	($3)	($2)

Changes_in_Accumulated_Other_C2

Changes in Accumulated Other Comprehensive Income (Loss) by Component (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Changes in Accumulated other comprehensive income (loss) [Roll Forward]
Accumulated other comprehensive income (loss), beginning balance	$126		$831
Other comprehensive income (loss), before reclassifications	-16		-722
Amounts reclassified from accumulated other comprehensive income (loss)	-3		-4
Other comprehensive income (loss), net of tax	-13	263	-718	650
Accumulated other comprehensive income (loss), ending balance	113		113
Other comprehensive income (loss), tax, portion attributable to parent, parenthetical disclosures [Abtract]
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	1		3
Tax (expense) benefit on other comprehensive income (loss)	36		377
Net unrealized gains (losses) on investments with OTTI Losses [Member]
Changes in Accumulated other comprehensive income (loss) [Roll Forward]
Accumulated other comprehensive income (loss), beginning balance	26		20
Other comprehensive income (loss), before reclassifications	-4		2
Amounts reclassified from accumulated other comprehensive income (loss)	-1		-1
Other comprehensive income (loss), net of tax	-3		3
Accumulated other comprehensive income (loss), ending balance	23		23
Other comprehensive income (loss), tax, portion attributable to parent, parenthetical disclosures [Abtract]
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)
Tax (expense) benefit on other comprehensive income (loss)	1		-2
Net unrealized gains (losses) on other investments [Member]
Changes in Accumulated other comprehensive income (loss) [Roll Forward]
Accumulated other comprehensive income (loss), beginning balance	724		1,371
Other comprehensive income (loss), before reclassifications	-68		-706
Amounts reclassified from accumulated other comprehensive income (loss)	2		11
Other comprehensive income (loss), net of tax	-70		-717
Accumulated other comprehensive income (loss), ending balance	654		654
Other comprehensive income (loss), tax, portion attributable to parent, parenthetical disclosures [Abtract]
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	-2		-5
Tax (expense) benefit on other comprehensive income (loss)	38		387
Pension and postretirement benefits [Member]
Changes in Accumulated other comprehensive income (loss) [Roll Forward]
Accumulated other comprehensive income (loss), beginning balance	-711		-721
Other comprehensive income (loss), before reclassifications
Amounts reclassified from accumulated other comprehensive income (loss)	-4		-14
Other comprehensive income (loss), net of tax	4		14
Accumulated other comprehensive income (loss), ending balance	-707		-707
Other comprehensive income (loss), tax, portion attributable to parent, parenthetical disclosures [Abtract]
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	3		8
Tax (expense) benefit on other comprehensive income (loss)	-3		-8
Cumulative foreign currency translation adjustment [Member]
Changes in Accumulated other comprehensive income (loss) [Roll Forward]
Accumulated other comprehensive income (loss), beginning balance	87		161
Other comprehensive income (loss), before reclassifications	56		-18
Amounts reclassified from accumulated other comprehensive income (loss)
Other comprehensive income (loss), net of tax	56		-18
Accumulated other comprehensive income (loss), ending balance	143		143
Other comprehensive income (loss), tax, portion attributable to parent, parenthetical disclosures [Abtract]
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)
Tax (expense) benefit on other comprehensive income (loss)