CNA Financial (CNA) 10-Q 5 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document	3 Months Ended
	Mar. 31, 2015	1-May-15
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	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		270,245,346

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues
Net earned premiums	$1,687	$1,806
Net investment income	558	526
Net realized investment gains (losses):
Other-than-temporary impairment losses	-12	-2
Portion of other-than-temporary impairments recognized in Other comprehensive income	0	0
Net other-than-temporary impairment losses recognized in earnings	-12	-2
Other net realized investment gains (loss)	22	48
Net realized investment gains (losses)	10	46
Other revenues	97	85
Total revenues	2,352	2,463
Claims, Benefits and Expenses
Insurance claims and policyholders' benefits	1,339	1,446
Amortization of deferred acquisition costs	303	329
Other operating expenses	358	346
Interest	39	44
Total claims, benefits and expenses	2,039	2,165
Income (loss) from continuing operations before income tax	313	298
Income tax expense (benefit)	-80	-78
Net income (loss) from continuing operations	233	220
(Loss) income from discontinued operations, net of income tax benefit (expense)	0	-207
Net income (loss)	$233	$13
Basic Earnings (Loss) Per Share Attributable to CNA
Income from continuing operations	$0.86	$0.82
(Loss) income from discontinued operations	$0	($0.77)
Basic earnings per share	$0.86	$0.05
Diluted Earnings (Loss) Per Share Attributable to CNA
Income (loss) from continuing operations	$0.86	$0.81
(Loss) income from discontinued operations	$0	($0.76)
Diluted earnings (loss) per share	$0.86	$0.05
Dividends per share	$2.25	$1.25
Weighted Average Outstanding Common Stock and Common Stock Equivalents
Basic	0	0
Diluted	0	0

Consolidated_Statements_of_Ope1

Consolidated Statements of Operations Parenthetical (Parentheticals) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Income tax benefit (expense) on discontinued operations	$0	$38

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Other Comprehensive Income (Loss), Net of Tax, Changes In:
Net unrealized gains (losses) on investments with other-than-temporary impairments	($1)	$12
Net unrealized gains (losses) on other investments	112	237
Net unrealized gains (losses) on investments	111	249
Net unrealized gains (losses) on discontinued operations	0	8
Foreign currency translation adjustment	-96	-8
Pension and postretirement benefits	6	1
Other comprehensive income (loss)	21	250
Net income (loss)	233	13
Total comprehensive income (loss)	$254	$263

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Assets
Fixed maturity securities at fair value	$40,605	$40,768
Equity securities at fair value	225	222
Limited partnership investments	2,967	2,937
Other invested assets	43	41
Mortgage loans	586	588
Short term investments	1,506	1,706
Total investments	45,932	46,262
Cash	201	190
Reinsurance receivables	4,720	4,694
Insurance receivables	2,050	1,936
Accrued investment income	430	405
Deferred acquisition costs	616	600
Deferred income taxes	57	191
Property and equipment at cost	298	295
Goodwill	151	152
Other assets	1,010	841
Total assets	55,465	55,566
Liabilities
Claim and claim adjustment expenses	23,248	23,271
Unearned premiums	3,710	3,592
Future policy benefits	9,747	9,490
Policyholders’ funds	0	27
Long term debt	2,560	2,559
Other liabilities	3,763	3,833
Total liabilities	43,028	42,772
Stockholders' Equity
Common stock	683	683
Additional paid-in capital	2,143	2,151
Retained earnings	9,270	9,645
Accumulated other comprehensive income (loss)	421	400
Treasury stock	-79	-84
Notes receivable for the issuance of common stock	-1	-1
Total stockholders’ equity	12,437	12,794
Total liabilities and stockholders' equity	$55,465	$55,566

Consolidated_Balance_Sheet_Par

Consolidated Balance Sheet Parentheticals (Parentheticals) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Fixed maturities securities at amortized cost	$36,875	$37,335
Equity securities at cost	213	210
Allowance for uncollectible reinsurance receivables	48	48
Allowance for uncollectible insurance receivables	59	61
Accumulated depreciation on property and equipment	364	364
Due to Related Parties	$6	$153
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	270,241,545	269,980,202
Treasury stock, shares	2,798,698	3,060,041

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash Flows from Operating Activities
Net income (loss)	$233	$13
Adjustments to reconcile net income (loss) to net cash flows provided (used) by operating activities:
Impairment loss on sale of subsidiary	0	255
Deferred income tax expense (benefit)	71	25
Trading portfolio activity	13	21
Net realized investment (gains) losses	-10	-47
Equity method investees	-91	132
Net amortization of investments	0	-1
Depreciation and amortization	19	20
Changes in:
Receivables, net	-157	126
Accrued investment income	-25	-36
Deferred acquisition costs	-13	-21
Insurance reserves	304	85
Other assets	-34	-35
Other liabilities	-235	-372
Other, net	19	3
Total adjustments	-139	155
Net cash flows provided (used) by operating activities	94	168
Dispositions:
Fixed maturity securities - sales	1,144	1,550
Fixed maturity securities - maturities, calls and redemptions	1,144	851
Equity securities	2	11
Limited partnerships	20	68
Mortgage loans	3	13
Purchases:
Fixed maturity securities	-1,919	-2,072
Equity securities	-5	-5
Limited partnerships	-34	-73
Mortgage Loans	-8	0
Change in other investments	7	0
Change in short term investments	190	-688
Purchases of property and equipment	-20	-10
Other, net	2	1
Net cash flows provided (used) by investing activities	526	-354
Cash Flows from Financing Activities
Dividends paid to common stockholders	-608	-338
Proceeds from the issuance of debt	0	546
Other, net	5	2
Net cash flows provided (used) by financing activities	-603	210
Effect of foreign exchange rate changes on cash	-6	1
Transfer of cash to assets held for sale	0	-14
Net change in cash	11	11
Cash, beginning of year	190	195
Cash, end of period	$201	$206

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (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
Balance at Dec. 31, 2013		$683	$2,145	$9,495	$442	($91)	($23)
Net income (loss)	13			13
Other comprehensive income (loss)	250				250
Dividends paid to common stockholders				-338
Stock-based compensation			-1			6
Decrease (increase) in notes receivable from the issuance of common stock							1
Balance at Mar. 31, 2014	12,582	683	2,144	9,170	692	-85	-22
Balance at Dec. 31, 2014	12,794	683	2,151	9,645	400	-84	-1
Net income (loss)	233			233
Other comprehensive income (loss)	21				21
Dividends paid to common stockholders				-608
Stock-based compensation			-8			5
Decrease (increase) in notes receivable from the issuance of common stock							0
Balance at Mar. 31, 2015	$12,437	$683	$2,143	$9,270	$421	($79)	($1)

General

General	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	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. Loews Corporation (Loews) owned approximately 90% of the outstanding common stock of CNAF as of March 31, 2015.
	The accompanying Condensed Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). Intercompany amounts have been eliminated. 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, 2014, 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 March 31, 2015 and for the three months ended March 31, 2015 and 2014 is unaudited. However, in the opinion of management, the interim data includes all adjustments, including normal recurring adjustments, 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.
	Sale of Continental Assurance Company (CAC)
	On August 1, 2014, the Company completed the sale of the common stock of CAC, the Company's former life insurance subsidiary. In the first quarter of 2014, the Company recorded an after-tax impairment loss of $214 million related to the sale. The Company elected to include CAC cash flow activity in the comparative Condensed Consolidated Statement of Cash Flows. Further information on discontinued operations is provided in Note K to the Condensed Consolidated Financial Statements.

Earnings_Per_Share_Earnings_Pe

Earnings Per Share Earnings Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	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 effect 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 months ended March 31, 2015 and 2014, approximately 654 thousand and 660 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 182 thousand and 110 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	3 Months Ended
	Mar. 31, 2015
Investments [Abstract]
Investments	Note C. Investments
	The significant components of Net investment income are presented in the following table.
	Three months ended March 31
	(In millions)	2015			2014
	Fixed maturity securities	$	443		$	452
	Short term investments	2			1
	Limited partnership investments	114			73
	Equity securities	3			2
	Mortgage loans	8			6
	Trading portfolio	2			3
	Other	—			2
	Gross investment income	572			539
	Investment expense	(14		)	(13		)
	Net investment income	$	558		$	526
	Net realized investment gains (losses) are presented in the following table.
	Three months ended March 31
	(In millions)	2015			2014
	Net realized investment gains (losses):
	Fixed maturity securities:
	Gross realized gains	$	33		$	53
	Gross realized losses	(21		)	(15		)
	Net realized investment gains (losses) on fixed maturity securities	12			38
	Equity securities:
	Gross realized gains	1			5
	Gross realized losses	(1		)	—
	Net realized investment gains (losses) on equity securities	—			5
	Derivatives	(1		)	—
	Short term investments and other	(1		)	3
	Net realized investment gains (losses)	$	10		$	46
	The components of Net other-than-temporary impairment (OTTI) losses recognized in earnings by asset type are presented in the following table.
	Three months ended March 31
	(In millions)	2015			2014
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	5		$	1
	States, municipalities and political subdivisions	5			—
	Asset-backed - residential mortgage-backed	1			1
	Total fixed maturity securities available-for-sale	11			2
	Equity securities available-for-sale:
	Common stock	1			—
	Net OTTI losses recognized in earnings	$	12		$	2
	The following tables present a summary of fixed maturity and equity securities.
	March 31, 2015	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	$	16,721		$	1,867		$	43	$	18,545	$	—
	States, municipalities and political subdivisions	11,407			1,536			9		12,934		—
	Asset-backed:
	Residential mortgage-backed	4,998			241			13		5,226		(51		)
	Commercial mortgage-backed	2,151			114			5		2,260		(3		)
	Other asset-backed	1,109			15			1		1,123		—
	Total asset-backed	8,258			370			19		8,609		(54		)
	U.S. Treasury and obligations of government-sponsored enterprises	24			6			—		30		—
	Foreign government	390			19			—		409		—
	Redeemable preferred stock	39			3			—		42		—
	Total fixed maturity securities available-for-sale	36,839			3,801			71		40,569		$	(54	)
	Total fixed maturity securities trading	36								36
	Equity securities available-for-sale:
	Common stock	41			9			—		50
	Preferred stock	172			7			4		175
	Total equity securities available-for-sale	213			16			4		225
	Total	$	37,088		$	3,817		$	75	$	40,830
	December 31, 2014	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	$	17,210		$	1,721		$	61	$	18,870	$	—
States, municipalities and political subdivisions	11,285			1,463			8		12,740		—
Asset-backed:
Residential mortgage-backed	5,028			218			13		5,233		(53		)
Commercial mortgage-backed	2,056			93			5		2,144		(2		)
Other asset-backed	1,234			11			10		1,235		—
Total asset-backed	8,318			322			28		8,612		(55		)
U.S. Treasury and obligations of government-sponsored enterprises	26			5			—		31		—
Foreign government	438			16			—		454		—
Redeemable preferred stock	39			3			—		42		—
Total fixed maturity securities available-for-sale	37,316			3,530			97		40,749		$	(55	)
Total fixed maturity securities trading	19								19
Equity securities available-for-sale:
Common stock	38			9			—		47
Preferred stock	172			5			2		175
Total equity securities available-for-sale	210			14			2		222
Total	$	37,545		$	3,544		$	99	$	40,990
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. As of March 31, 2015 and December 31, 2014, the net unrealized gains on investments included in AOCI were net of after-tax Shadow Adjustments of $1,370 million and $1,288 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 present the estimated fair value and gross unrealized losses of 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.
	Less than 12 Months						12 Months or Longer				Total
March 31, 2015	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	$	840		$	31		$	139	$	12	$	979		$	43
States, municipalities and political subdivisions	479			6			100		3		579			9
Asset-backed:
Residential mortgage-backed	318			5			148		8		466			13
Commercial mortgage-backed	175			3			62		2		237			5
Other asset-backed	187			1			5		—		192			1
Total asset-backed	680			9			215		10		895			19
U.S. Treasury and obligations of government-sponsored enterprises	3			—			—		—		3			—
Foreign government	13			—			1		—		14			—
Total fixed maturity securities available-for-sale	2,015			46			455		25		2,470			71
Equity securities available-for-sale:
Preferred stock	15			4			—		—		15			4
Total	$	2,030		$	50		$	455	$	25	$	2,485		$	75
	Less than 12 Months						12 Months or Longer				Total
December 31, 2014	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	$	1,330		$	46		$	277	$	15	$	1,607		$	61
States, municipalities and political subdivisions	335			5			127		3		462			8
Asset-backed:
Residential mortgage-backed	293			5			189		8		482			13
Commercial mortgage-backed	264			2			99		3		363			5
Other asset-backed	607			10			7		—		614			10
Total asset-backed	1,164			17			295		11		1,459			28
U.S. Treasury and obligations of government-sponsored enterprises	3			—			4		—		7			—
Foreign government	3			—			3		—		6			—
Redeemable preferred stock	3			—			—		—		3			—
Total fixed maturity securities available-for-sale	2,838			68			706		29		3,544			97
Equity securities available-for-sale:
Preferred stock	17			2			1		—		18			2
Total	$	2,855		$	70		$	707	$	29	$	3,562		$	99
Based on current facts and circumstances, the Company believes the unrealized losses presented in the March 31, 2015 table above, are not indicative of the ultimate collectibility of the current amortized cost of the securities, but rather are primarily attributable to changes in interest rates and credit spreads, market illiquidity and other factors. The Company has no current intent to sell securities with unrealized losses, 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 as of March 31, 2015.
The following table presents the activity related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held as of March 31, 2015 and 2014 for which a portion of an OTTI loss was recognized in Other comprehensive income.
Three months ended March 31
(In millions)	2015			2014
Beginning balance of credit losses on fixed maturity securities	$	62		$	74
Reductions for securities sold during the period	(1		)	(2		)
Reductions for securities the Company intends to sell or more likely than not will be required to sell	—			(3		)
Ending balance of credit losses on fixed maturity securities	$	61		$	69
Contractual Maturity
The following table presents available-for-sale fixed maturity securities by contractual maturity.
	March 31, 2015						December 31, 2014
(In millions)	Cost or			Estimated			Cost or		Estimated
	Amortized			Fair			Amortized		Fair
	Cost			Value			Cost		Value
Due in one year or less	$	2,011		$	2,043		$	2,479	$	2,511
Due after one year through five years	8,760			9,340			9,054		9,605
Due after five years through ten years	12,401			13,108			12,055		12,584
Due after ten years	13,667			16,078			13,728		16,049
Total	$	36,839		$	40,569		$	37,316	$	40,749
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.
Derivative Financial Instruments
The following tables present the aggregate contractual or notional amounts and estimated fair values related to derivative financial instruments.
March 31, 2015	Contractual/			Estimated Fair Value
	Notional
(In millions)	Amount			Asset			Liability
Without hedge designation
Currency forwards	$	18		$	2		$	—
Equity warrants	5			—			—
Embedded derivative on funds withheld liability	184			—			5
Total				$	2		$	5
December 31, 2014	Contractual/			Estimated Fair Value
	Notional
(In millions)	Amount			Asset			Liability
Without hedge designation
Currency forwards	$	9		$	—		$	—
Equity warrants	5			—			—
Embedded derivative on funds withheld liability	184			—			3
Total				$	—		$	3
Derivative financial instruments are presented gross 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 as of March 31, 2015 and December 31, 2014.
Investment Commitments
As of March 31, 2015, the Company had committed approximately $338 million to future capital calls from various third-party limited partnership investments in exchange for an ownership interest in the related partnerships.
As of March 31, 2015, the Company had mortgage loan commitments of $41 million representing signed loan applications received and accepted.
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 March 31, 2015, the Company had commitments to purchase or fund additional amounts of $82 million and sell $71 million under the terms of such securities.

Fair_Value

Fair Value	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value	Note D. 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. 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 performs an independent analysis of the inputs and assumptions used to price 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 presented in the following tables.
	March 31, 2015									Total
										Assets/ Liabilities
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	29	$	18,337		$	186		$	18,552
	States, municipalities and political subdivisions	—		12,877			86			12,963
	Asset-backed:
	Residential mortgage-backed	—		4,994			232			5,226
	Commercial mortgage-backed	—		2,196			64			2,260
	Other asset-backed	—		570			553			1,123
	Total asset-backed	—		7,760			849			8,609
	U.S. Treasury and obligations of government-sponsored enterprises	29		1			—			30
	Foreign government	37		372			—			409
	Redeemable preferred stock	30		12			—			42
	Total fixed maturity securities	125		39,359			1,121			40,605
	Equity securities	149		63			13			225
	Derivative financial instruments	—		2			—			2
	Other invested assets, excluding derivative financial instruments	—		41			—			41
	Short term investments	742		678			—			1,420
	Life settlement contracts, included in Other assets	—		—			79			79
	Total assets	$	1,016	$	40,143		$	1,213		$	42,372
	Liabilities
	Other liabilities	$	—	$	5		$	—		$	5
	Total liabilities	$	—	$	5		$	—		$	5
	December 31, 2014									Total
										Assets/Liabilities
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	32	$	18,695		$	162		$	18,889
	States, municipalities and political subdivisions	—		12,646			94			12,740
	Asset-backed:
	Residential mortgage-backed	—		5,044			189			5,233
	Commercial mortgage-backed	—		2,061			83			2,144
	Other asset-backed	—		580			655			1,235
	Total asset-backed	—		7,685			927			8,612
	U.S. Treasury and obligations of government-sponsored enterprises	28		3			—			31
	Foreign government	41		413			—			454
	Redeemable preferred stock	30		12			—			42
	Total fixed maturity securities	131		39,454			1,183			40,768
	Equity securities	145		61			16			222
	Other invested assets	—		41			—			41
	Short term investments	681		963			—			1,644
	Life settlement contracts, included in Other assets	—		—			82			82
	Total assets	$	957	$	40,519		$	1,281		$	42,757
	Liabilities
	Other liabilities	$	—	$	3		$	—		$	3
	Total liabilities	$	—	$	3		$	—		$	3
	The following tables present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3).
	Level 3	Balance as of		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 as of		Unrealized gains (losses) on Level 3 assets and liabilities held as of March 31, 2015 recognized in Net income (loss)
	(In millions)	January 1,																Level 3		of Level 3			March 31,
		2015																					2015
	Fixed maturity securities:
	Corporate and other bonds	$	162	$	1		$	—		$	12	$	(12	)	$	(14	)	$	37	$	—		$	186	$	—
States, municipalities and political subdivisions	94		1			—			—		—			(9		)	—		—			86		—
Asset-backed:
Residential mortgage-backed	189		1			—			72		—			(10		)	—		(20		)	232		—
Commercial mortgage-backed	83		1			1			6		—			(1		)	—		(26		)	64		—
Other asset-backed	655		1			9			35		(144		)	(3		)	—		—			553		—
Total asset-backed	927		3			10			113		(144		)	(14		)	—		(46		)	849		—
Total fixed maturity securities	1,183		5			10			125		(156		)	(37		)	37		(46		)	1,121		—
Equity securities	16		—			(3		)	—		—			—			—		—			13		—
Life settlement contracts	82		13			—			—		—			(16		)	—		—			79		1
Total	$	1,281	$	18		$	7		$	125	$	(156	)	$	(53	)	$	37	$	(46	)	$	1,213	$	1
Level 3	Balance as of		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 as of		Unrealized gains (losses) on Level 3 assets and liabilities held as of March 31, 2014 recognized in Net income (loss)
(In millions)	January 1,																Level 3		of Level 3			31-Mar-14
	2014
Fixed maturity securities:
Corporate and other bonds	$	204	$	1		$	1		$	5	$	(4	)	$	(5	)	$	3	$	(16	)	$	189	$	—
States, municipalities and political subdivisions	71		—			1			—		—			—			14		—			86		—
Asset-backed:
Residential mortgage-backed	331		1			15			25		—			(21		)	21		(13		)	359		—
Commercial mortgage-backed	151		1			(1		)	—		—			(1		)	—		(24		)	126		—
Other asset-backed	446		1			—			148		(83		)	(72		)	—		(1		)	439		—
Total asset-backed	928		3			14			173		(83		)	(94		)	21		(38		)	924		—
Total fixed maturity securities	1,203		4			16			178		(87		)	(99		)	38		(54		)	1,199		—
Equity securities	11		3			(4		)	—		(8		)	—			—		—			2		—
Life settlement contracts	88		10			—			—		—			(11		)	—		—			87		1
Separate account business	1		—			—			—		—			—			—		(1		)	—		—
Total	$	1,303	$	17		$	12		$	178	$	(95	)	$	(110	)	$	38	$	(55	)	$	1,288	$	1
Net realized and unrealized gains and losses, including those 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
Other liabilities - Derivative financial instruments		Net realized investment gains (losses)
Securities shown on the previous pages may be transferred in or out of levels within the fair value hierarchy based on the availability of observable market information and quoted prices used to determine the fair value of the security. The availability of observable market information and quoted prices varies based on market conditions and trading volume. During the three months ended March 31, 2015 there were no transfers between Level 1 and Level 2. During the three months ended March 31, 2014 there were $23 million of transfers from Level 2 to Level 1 and $1 million from Level 1 to Level 2. 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
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. All classes of Level 2 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 for all classes of fixed maturity securities include prices from recently executed transactions of similar securities, marketplace 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. Fixed maturity 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 private placement debt securities whose fair value 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.
Derivative Financial Investments
Level 1 securities include exchange traded derivatives, primarily futures, valued using quoted market prices. Level 2 securities primarily include the embedded derivative on funds withheld liability and currency forwards. The embedded derivative on funds withheld liability is valued using the change in fair value of the assets supporting the funds withheld payable, which are fixed maturity securities valued with observable inputs. Currency forwards are valued using observable market forward rates. Over-the-counter derivatives, principally interest rate swaps, total return 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.
Overseas Deposits
Overseas deposits, which can be redeemed at net asset value in 90 days or less, are classified as Level 2.
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.
Significant Unobservable Inputs
The following tables present 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.
31-Mar-15
(In millions)	Fair Value		Valuation Technique(s)		Unobservable Input(s)	Range
						(Weighted Average)
Fixed maturity securities	$	102	Discounted cash flow		Credit spread	2% - 13% (3%)
Equity securities	13		Market approach		Private offering price	$10 - $4,400 per share ($682)
Life settlement contracts	79		Discounted cash flow		Discount rate risk premium	9%
					Mortality assumption	55% - 1676% (164%)
31-Dec-14
(In millions)	Fair Value		Valuation Technique(s)		Unobservable Input(s)	Range
						(Weighted Average)
Fixed maturity securities	$	101	Discounted cash flow		Credit spread	2% - 13% (3%)
Equity securities	16		Market approach		Private offering price	$12 - $4,391 per share ($600)
Life settlement contracts	82		Discounted cash flow		Discount rate risk premium	9%
					Mortality assumption	55% - 1676% (163%)
For fixed maturity securities, an increase to the 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 assets and liabilities which are not measured at fair value on the Condensed Consolidated Balance Sheets are presented in the following tables.
March 31, 2015	Carrying		Estimated Fair Value
(In millions)	Amount		Level 1			Level 2			Level 3		Total
Assets
Notes receivable for the issuance of common stock	$	1	$	—		$	—		$	1	$	1
Mortgage loans	586		—			—			612		612
Liabilities
Long term debt	$	2,560	$	—		$	2,908		$	—	$	2,908
December 31, 2014	Carrying		Estimated Fair Value
(In millions)	Amount		Level 1			Level 2			Level 3		Total
Assets
Notes receivable for the issuance of common stock	$	1	$	—		$	—		$	1	$	1
Mortgage loans	588		—			—			608		608
Liabilities
Long term debt	$	2,559	$	—		$	2,883		$	—	$	2,883
The following methods and assumptions were used to estimate the fair value of these financial assets and liabilities.
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.
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	3 Months Ended
	Mar. 31, 2015
Claim and Claim Adjustment Expense Reserves [Abstract]
Claim and Claim Adjustment Expense Reserves	Note E. 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 incurred but not reported (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 $29 million for the three months ended March 31, 2015. Catastrophe losses in 2015 related primarily to U.S. weather-related events. The Company reported catastrophe losses, net of reinsurance, of $74 million for the three months ended March 31, 2014.
	The fourth quarter of 2014 asbestos and environmental pollution (A&EP) reserve review was not completed because additional information and analysis on inuring third-party reinsurance recoveries were needed to finalize the review. The review and analysis of this information continues, and the Company expects to complete the review in the second quarter of 2015. Given the significance of the information and analysis needed to finalize the remaining elements of the review, the Company is not able to estimate the impact, if any, of this uncertainty on the Company's Condensed Consolidated Financial Statements.
	Net Prior Year Development
	The following tables and discussion present net prior year development recorded for Specialty, Commercial, International and Corporate & Other Non-Core segments.
	Three months ended March 31, 2015
	(In millions)	Specialty			Commercial			International			Corporate		Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	2		$	(5	)	$	(4	)	$	—	$	(7	)
	Pretax (favorable) unfavorable premium development	(6		)	(1		)	16			—		9
	Total pretax (favorable) unfavorable net prior year development	$	(4	)	$	(6	)	$	12		$	—	$	2
	Three months ended March 31, 2014
	(In millions)	Specialty			Commercial			International			Corporate		Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(3	)	$	18		$	10		$	—	$	25
	Pretax (favorable) unfavorable premium development	(6		)	(18		)	(7		)	—		(31		)
	Total pretax (favorable) unfavorable net prior year development	$	(9	)	$	—		$	3		$	—	$	(6	)
	Specialty
	The following table presents further detail of the net prior year claim and allocated claim adjustment expense reserve development (development) recorded for the Specialty segment.
	Three months ended March 31
	(In millions)	2015			2014
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Medical Professional Liability	$	14		$	—
	Other Professional Liability and Management Liability	(3		)	(6		)
	Surety	1			1
	Warranty	—			—
	Other	(10		)	2
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	2		$	(3	)
	2015
	Overall, unfavorable development for medical professional liability was primarily related to increased frequency in the Aging Services book for accident years 2013 and 2014, partially offset by better than expected severity in accident years 2010 and prior.
	Favorable development for other coverages was primarily due to better than expected frequency in property coverages provided to Specialty customers in accident year 2014.
	2014
	Favorable development for other professional liability and management liability was related to better than expected loss emergence in accident years 2004 and prior.
	Commercial
	The following table presents further detail of the development recorded for the Commercial segment.
	Three months ended March 31
	(In millions)	2015			2014
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Commercial Auto	$	—		$	20
	General Liability	4			—
	Workers' Compensation	(1		)	11
	Property and Other	(8		)	(13		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(5	)	$	18
	2015
	Favorable development for property and other was due to lower than expected loss emergence from 2014 catastrophe events.
	2014
	Unfavorable development for commercial auto was primarily related to higher than expected frequency in accident years 2012 and 2013 and higher than expected loss emergence in accident years 2010 and 2011.
	Unfavorable development for workers' compensation was primarily due to the recognition of losses related to favorable premium development in accident year 2013.
	Favorable development for property and other was primarily due to better than expected loss emergence in catastrophe losses in accident year 2013.
	International
	The following table presents further detail of the development recorded for the International segment.
	Three months ended March 31
	(In millions)	2015			2014
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Medical Professional Liability	$	—		$	1
	Other Professional Liability	—			(1		)
	Liability	(5		)	(2		)
	Property & Marine	(6		)	8
	Other	7			(6		)
	Commutations	—			10
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(4	)	$	10
2014
Reinsurance commutations in the first quarter of 2014 reduced ceded losses from prior years. Overall the commutations increased net operating income because of the release of the related allowance for uncollectible reinsurance.

Legal_Proceedings_and_Continge

Legal Proceedings and Contingent Liabilities	3 Months Ended
	Mar. 31, 2015
Legal Proceedings and Contingent Liabilities [Abstract]
Legal Proceedings and Contingent Liabilities	Note F. 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	3 Months Ended
	Mar. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Benefit Plans	Note G. Benefit Plans
	The components of net periodic cost (benefit) are presented in the following table.
	Three months ended March 31
	(In millions)	2015			2014
	Pension cost (benefit)
	Service cost	$	2		$	3
	Interest cost on projected benefit obligation	28			33
	Expected return on plan assets	(43		)	(48		)
	Amortization of net actuarial loss	9			6
	Net periodic pension cost (benefit)	$	(4	)	$	(6	)
	Postretirement cost (benefit)
	Amortization of prior service credit	$	—		$	(4	)
	Net periodic postretirement cost (benefit)	$	—		$	(4	)

Commitments_Contingencies_and_

Commitments, Contingencies, and Guarantees	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies, and Guarantees	Note H. 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, as of March 31, 2015, the maximum potential future lease payments and other related costs that the Company could be required to pay under this guarantee, in excess of amounts already recorded, were approximately $41 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
	As of March 31, 2015 and December 31, 2014, the Company had recorded liabilities of approximately $5 million related to guarantee and indemnification agreements and management believes that it is not likely that any future indemnity claims will be significantly greater than the amounts recorded.
	In the course of selling business entities and assets to third parties, the Company agreed to guarantee the performance of certain obligations of a previously owned subsidiary and 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 guarantee and indemnification agreements in effect for sales of business entities, assets and third-party loans may include provisions that survive indefinitely. As of March 31, 2015, the aggregate amount related to quantifiable guarantees was $375 million and the aggregate amount related to indemnification agreements was $324 million. Should the Company be required to make payments under the guarantee, it would have the right to seek reimbursement in certain cases from an affiliate of a previously owned subsidiary.
	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 March 31, 2015, 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. Certain provisions of the indemnification agreements survive indefinitely while others survive until the applicable statutes of limitation expire or until the agreed-upon contract terms expire.
	In the normal course of business, the Company also provided guarantees, if the primary obligor fails to perform, to holders of structured settlement annuities provided by a previously owned subsidiary, which are estimated to mature through 2120. The potential amount of future payments the Company could be required to pay under these guarantees was approximately $2.0 billion as of March 31, 2015. The Company does not believe a payable is likely under these guarantees, as the Company is the beneficiary of a trust that must be maintained at a level that approximates the discounted reserves for these annuities.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss) by Component	3 Months Ended
	Mar. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss) by Component	Note I. Accumulated Other Comprehensive Income (Loss) by Component
	The following tables present the changes in Accumulated other comprehensive income (loss) by component.
	(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 as of January 1, 2015	$	36		$	942		$	(633	)	$	55		$	400
	Other comprehensive income (loss) before reclassifications	(1		)	121			—			(96		)	24
	Amounts reclassified from Accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $0, $3, $0 and $3	—			9			(6		)	—			3
	Other comprehensive income (loss) after tax (expense) benefit of $0, $(62), $(3), $0 and $(65)	(1		)	112			6			(96		)	21
	Balance as of March 31, 2015	$	35		$	1,054		$	(627	)	$	(41	)	$	421
	(In millions)	Net unrealized gains (losses) on investments with OTTI losses			Net unrealized gains (losses) on other investments			Net unrealized gains (losses) on discontinued operations			Pension and postretirement benefits			Cumulative foreign currency translation adjustment			Total
	Balance as of January 1, 2014	$	26		$	692		$	—		$	(426	)	$	150		$	442
	Transfer to net assets held for sale	(5		)	(17		)	22			—			—			—
	Other comprehensive income (loss) before reclassifications	12			264			8			—			(8		)	276
	Amounts reclassified from Accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(14), $0, $1, $0 and $(13)	—			27			—			(1		)	—			26
	Other comprehensive income (loss) after tax (expense) benefit of $(6), $(127), $(5), $(1), $0 and $(139)	12			237			8			1			(8		)	250
	Balance as of March 31, 2014	$	33		$	912		$	30		$	(425	)	$	142		$	692
	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)
	Net unrealized gains (losses) on discontinued operations		Income (loss) from discontinued operations
	Pension and postretirement benefits		Other operating expenses

Business_Segments

Business Segments	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Business Segments	Note J. Business Segments
	The Company's core property and casualty commercial insurance operations are aggregated and reported in three business segments: Specialty, Commercial and International. 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 to the Consolidated Financial Statements within CNAF's Annual Report on Form 10-K for the year ended December 31, 2014. 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 (loss), 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, 2) income or loss from discontinued operations and 3) any cumulative effects of changes in accounting guidance. The calculation of net operating income excludes net realized investment gains (losses) because net realized investment gains (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 continuing operations and selected balance sheet items by segment are presented in the following tables.
	Three months ended March 31, 2015	Specialty			Commercial			International			Life &			Corporate
											Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	680		$	678		$	191		$	138		$	—		$	—		$	1,687
	Net investment income	155			204			14			179			6			—			558
	Other revenues	78			9			—			9			2			(1		)	97
	Total operating revenues	913			891			205			326			8			(1		)	2,342
	Claims, Benefits and Expenses
	Net incurred claims and benefits	429			454			116			340			(4		)	—			1,335
	Policyholders’ dividends	1			3			—			—			—			—			4
	Amortization of deferred acquisition costs	144			117			35			7			—			—			303
	Other insurance related expenses	69			127			37			35			—			—			268
	Other expenses	67			8			5			4			46			(1		)	129
	Total claims, benefits and expenses	710			709			193			386			42			(1		)	2,039
	Operating income (loss) before income tax	203			182			12			(60		)	(34		)	—			303
	Income tax (expense) benefit on operating income (loss)	(68		)	(62		)	(3		)	43			12			—			(78		)
	Net operating income (loss)	135			120			9			(17		)	(22		)	—			225
	Net realized investment gains (losses)	4			4			1			1			—			—			10
	Income tax (expense) benefit on net realized investment gains (losses)	(1		)	(3		)	—			2			—			—			(2		)
	Net realized investment gains (losses), after tax	3			1			1			3			—			—			8
	Net income (loss) from continuing operations	$	138		$	121		$	10		$	(14	)	$	(22	)	$	—		$	233
	March 31, 2015
	(In millions)
	Reinsurance receivables	$	671		$	675		$	207		$	543		$	2,672		$	—		$	4,768
	Insurance receivables	808			1,004			282			13			2			—			2,109
	Deferred acquisition costs	307			225			84			—			—			—			616
	Goodwill	117			—			34			—			—			—			151
	Insurance reserves
	Claim and claim adjustment expenses	6,352			9,441			1,377			3,237			2,841			—			23,248
	Unearned premiums	1,794			1,329			449			139			—			(1		)	3,710
	Future policy benefits	—			—			—			9,747			—			—			9,747
	Three months ended March 31, 2014	Specialty			Commercial			International			Life &			Corporate
											Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	692		$	735		$	241		$	139		$	—		$	(1	)	$	1,806
	Net investment income	144			191			15			171			5			—			526
	Other revenues	68			10			—			5			2			—			85
	Total operating revenues	904			936			256			315			7			(1		)	2,417
	Claims, Benefits and Expenses
	Net incurred claims and benefits	442			568			130			306			(3		)	—			1,443
	Policyholders’ dividends	1			2			—			—			—			—			3
	Amortization of deferred acquisition costs	143			123			55			8			—			—			329
	Other insurance related expenses	65			126			40			32			—			(1		)	262
	Other expenses	61			8			7			1			51			—			128
	Total claims, benefits and expenses	712			827			232			347			48			(1		)	2,165
	Operating income (loss) before income tax	192			109			24			(32		)	(41		)	—			252
	Income tax (expense) benefit on operating income (loss)	(63		)	(35		)	(8		)	30			14			—			(62		)
	Net operating income (loss)	129			74			16			(2		)	(27		)	—			190
	Net realized investment gains (losses)	11			10			3			16			6			—			46
	Income tax (expense) benefit on net realized investment gains (losses)	(3		)	(2		)	(3		)	(6		)	(2		)	—			(16		)
	Net realized investment gains (losses), after tax	8			8			—			10			4			—			30
	Net income (loss) from continuing operations	$	137		$	82		$	16		$	8		$	(23	)	$	—		$	220
	December 31, 2014
	(In millions)
	Reinsurance receivables	$	567		$	690		$	207		$	525		$	2,753		$	—		$	4,742
	Insurance receivables	778			954			250			13			2			—			1,997
Deferred acquisition costs	304			213			83			—			—			—			600
Goodwill	117			—			35			—			—			—			152
Insurance reserves
Claim and claim adjustment expenses	6,229			9,514			1,441			3,183			2,904			—			23,271
Unearned premiums	1,763			1,273			431			125			—			—			3,592
Future policy benefits	—			—			—			9,490			—			—			9,490
Policyholders’ funds	9			18			—			—			—			—			27
The following table presents revenue by line of business for each reportable segment. Revenues are comprised of Operating revenues and Net realized investment gains and losses.
Three months ended March 31
(In millions)	2015			2014
Specialty
Management & Professional Liability	$	697		$	704
Surety	120			122
Warranty & Alternative Risks	100			89
Specialty revenues	917			915
Commercial
Middle Market	409			403
Small Business	165			184
Other Commercial Insurance	321			359
Commercial revenues	895			946
International
Canada	55			71
CNA Europe	77			88
Hardy	74			100
International revenues	206			259
Life & Group Non-Core revenues	327			331
Corporate & Other Non-Core revenues	8			13
Eliminations	(1		)	(1		)
Total revenues	$	2,352		$	2,463

Discontinued_Operations

Discontinued Operations	3 Months Ended
	Mar. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Note K. Discontinued Operations
	The results of discontinued operations reflected in the Condensed Consolidated Statements of Operations are presented in the following table.
	Three months ended March 31
	(In millions)	2014
	Revenues
	Net investment income	$	41
	Net realized investment gains	1
	Total revenues	42
	Claims, Benefits and Expenses
	Insurance claims and policyholders' benefits	31
	Other operating expenses	1
	Total claims, benefits and expenses	32
	Income before income tax	10
	Income tax expense	(3		)
	Income from operations of discontinued operations, net of income tax	7
	Impairment loss on sale, net of income tax benefit of $41	(214		)
	Loss from discontinued operations	$	(207	)

Investments_Tables

Investments (Tables)	3 Months Ended
	Mar. 31, 2015
Investments [Abstract]
Net investment income	The significant components of Net investment income are presented in the following table.
	Three months ended March 31
	(In millions)	2015			2014
	Fixed maturity securities	$	443		$	452
	Short term investments	2			1
	Limited partnership investments	114			73
	Equity securities	3			2
	Mortgage loans	8			6
	Trading portfolio	2			3
	Other	—			2
	Gross investment income	572			539
	Investment expense	(14		)	(13		)
	Net investment income	$	558		$	526
Net realized investment gains (losses)	Net realized investment gains (losses) are presented in the following table.
	Three months ended March 31
	(In millions)	2015			2014
	Net realized investment gains (losses):
	Fixed maturity securities:
	Gross realized gains	$	33		$	53
	Gross realized losses	(21		)	(15		)
	Net realized investment gains (losses) on fixed maturity securities	12			38
	Equity securities:
	Gross realized gains	1			5
	Gross realized losses	(1		)	—
	Net realized investment gains (losses) on equity securities	—			5
	Derivatives	(1		)	—
	Short term investments and other	(1		)	3
	Net realized investment gains (losses)	$	10		$	46
Components of Net other-than-temporary impairment losses recognized in earnings by asset type	The components of Net other-than-temporary impairment (OTTI) losses recognized in earnings by asset type are presented in the following table.
	Three months ended March 31
	(In millions)	2015			2014
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	5		$	1
	States, municipalities and political subdivisions	5			—
	Asset-backed - residential mortgage-backed	1			1
	Total fixed maturity securities available-for-sale	11			2
	Equity securities available-for-sale:
	Common stock	1			—
	Net OTTI losses recognized in earnings	$	12		$	2
Summary of fixed maturity and equity securities	The following tables present a summary of fixed maturity and equity securities.
	March 31, 2015	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	$	16,721		$	1,867		$	43	$	18,545	$	—
	States, municipalities and political subdivisions	11,407			1,536			9		12,934		—
	Asset-backed:
	Residential mortgage-backed	4,998			241			13		5,226		(51		)
	Commercial mortgage-backed	2,151			114			5		2,260		(3		)
	Other asset-backed	1,109			15			1		1,123		—
	Total asset-backed	8,258			370			19		8,609		(54		)
	U.S. Treasury and obligations of government-sponsored enterprises	24			6			—		30		—
	Foreign government	390			19			—		409		—
	Redeemable preferred stock	39			3			—		42		—
	Total fixed maturity securities available-for-sale	36,839			3,801			71		40,569		$	(54	)
	Total fixed maturity securities trading	36								36
	Equity securities available-for-sale:
	Common stock	41			9			—		50
	Preferred stock	172			7			4		175
	Total equity securities available-for-sale	213			16			4		225
	Total	$	37,088		$	3,817		$	75	$	40,830
	December 31, 2014	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	$	17,210		$	1,721		$	61	$	18,870	$	—
	States, municipalities and political subdivisions	11,285			1,463			8		12,740		—
	Asset-backed:
	Residential mortgage-backed	5,028			218			13		5,233		(53		)
	Commercial mortgage-backed	2,056			93			5		2,144		(2		)
	Other asset-backed	1,234			11			10		1,235		—
	Total asset-backed	8,318			322			28		8,612		(55		)
	U.S. Treasury and obligations of government-sponsored enterprises	26			5			—		31		—
	Foreign government	438			16			—		454		—
	Redeemable preferred stock	39			3			—		42		—
	Total fixed maturity securities available-for-sale	37,316			3,530			97		40,749		$	(55	)
	Total fixed maturity securities trading	19								19
	Equity securities available-for-sale:
	Common stock	38			9			—		47
	Preferred stock	172			5			2		175
	Total equity securities available-for-sale	210			14			2		222
	Total	$	37,545		$	3,544		$	99	$	40,990
Securities in a gross unrealized loss position	The following tables present the estimated fair value and gross unrealized losses of 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.
		Less than 12 Months						12 Months or Longer				Total
	March 31, 2015	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	$	840		$	31		$	139	$	12	$	979		$	43
	States, municipalities and political subdivisions	479			6			100		3		579			9
	Asset-backed:
	Residential mortgage-backed	318			5			148		8		466			13
	Commercial mortgage-backed	175			3			62		2		237			5
	Other asset-backed	187			1			5		—		192			1
	Total asset-backed	680			9			215		10		895			19
	U.S. Treasury and obligations of government-sponsored enterprises	3			—			—		—		3			—
	Foreign government	13			—			1		—		14			—
	Total fixed maturity securities available-for-sale	2,015			46			455		25		2,470			71
	Equity securities available-for-sale:
	Preferred stock	15			4			—		—		15			4
	Total	$	2,030		$	50		$	455	$	25	$	2,485		$	75
		Less than 12 Months						12 Months or Longer				Total
	December 31, 2014	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	$	1,330		$	46		$	277	$	15	$	1,607		$	61
	States, municipalities and political subdivisions	335			5			127		3		462			8
	Asset-backed:
	Residential mortgage-backed	293			5			189		8		482			13
	Commercial mortgage-backed	264			2			99		3		363			5
	Other asset-backed	607			10			7		—		614			10
	Total asset-backed	1,164			17			295		11		1,459			28
	U.S. Treasury and obligations of government-sponsored enterprises	3			—			4		—		7			—
	Foreign government	3			—			3		—		6			—
	Redeemable preferred stock	3			—			—		—		3			—
	Total fixed maturity securities available-for-sale	2,838			68			706		29		3,544			97
	Equity securities available-for-sale:
	Preferred stock	17			2			1		—		18			2
	Total	$	2,855		$	70		$	707	$	29	$	3,562		$	99
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 presents the activity related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held as of March 31, 2015 and 2014 for which a portion of an OTTI loss was recognized in Other comprehensive income.
	Three months ended March 31
	(In millions)	2015			2014
	Beginning balance of credit losses on fixed maturity securities	$	62		$	74
	Reductions for securities sold during the period	(1		)	(2		)
	Reductions for securities the Company intends to sell or more likely than not will be required to sell	—			(3		)
	Ending balance of credit losses on fixed maturity securities	$	61		$	69
Contractual maturity	The following table presents available-for-sale fixed maturity securities by contractual maturity.
		March 31, 2015						December 31, 2014
	(In millions)	Cost or			Estimated			Cost or		Estimated
		Amortized			Fair			Amortized		Fair
		Cost			Value			Cost		Value
	Due in one year or less	$	2,011		$	2,043		$	2,479	$	2,511
	Due after one year through five years	8,760			9,340			9,054		9,605
	Due after five years through ten years	12,401			13,108			12,055		12,584
	Due after ten years	13,667			16,078			13,728		16,049
	Total	$	36,839		$	40,569		$	37,316	$	40,749
Summary of aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments	The following tables present the aggregate contractual or notional amounts and estimated fair values related to derivative financial instruments.
	March 31, 2015	Contractual/			Estimated Fair Value
		Notional
	(In millions)	Amount			Asset			Liability
	Without hedge designation
	Currency forwards	$	18		$	2		$	—
	Equity warrants	5			—			—
	Embedded derivative on funds withheld liability	184			—			5
	Total				$	2		$	5
	December 31, 2014	Contractual/			Estimated Fair Value
		Notional
	(In millions)	Amount			Asset			Liability
	Without hedge designation
	Currency forwards	$	9		$	—		$	—
	Equity warrants	5			—			—
	Embedded derivative on funds withheld liability	184			—			3
	Total				$	—		$	3

Fair_Value_Tables

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2015
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 presented in the following tables.
	March 31, 2015									Total
										Assets/ Liabilities
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	29	$	18,337		$	186		$	18,552
	States, municipalities and political subdivisions	—		12,877			86			12,963
	Asset-backed:
	Residential mortgage-backed	—		4,994			232			5,226
	Commercial mortgage-backed	—		2,196			64			2,260
	Other asset-backed	—		570			553			1,123
	Total asset-backed	—		7,760			849			8,609
	U.S. Treasury and obligations of government-sponsored enterprises	29		1			—			30
	Foreign government	37		372			—			409
	Redeemable preferred stock	30		12			—			42
	Total fixed maturity securities	125		39,359			1,121			40,605
	Equity securities	149		63			13			225
	Derivative financial instruments	—		2			—			2
	Other invested assets, excluding derivative financial instruments	—		41			—			41
	Short term investments	742		678			—			1,420
	Life settlement contracts, included in Other assets	—		—			79			79
	Total assets	$	1,016	$	40,143		$	1,213		$	42,372
	Liabilities
	Other liabilities	$	—	$	5		$	—		$	5
	Total liabilities	$	—	$	5		$	—		$	5
	December 31, 2014									Total
										Assets/Liabilities
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	32	$	18,695		$	162		$	18,889
	States, municipalities and political subdivisions	—		12,646			94			12,740
	Asset-backed:
	Residential mortgage-backed	—		5,044			189			5,233
	Commercial mortgage-backed	—		2,061			83			2,144
	Other asset-backed	—		580			655			1,235
	Total asset-backed	—		7,685			927			8,612
	U.S. Treasury and obligations of government-sponsored enterprises	28		3			—			31
	Foreign government	41		413			—			454
	Redeemable preferred stock	30		12			—			42
	Total fixed maturity securities	131		39,454			1,183			40,768
	Equity securities	145		61			16			222
	Other invested assets	—		41			—			41
	Short term investments	681		963			—			1,644
	Life settlement contracts, included in Other assets	—		—			82			82
	Total assets	$	957	$	40,519		$	1,281		$	42,757
	Liabilities
	Other liabilities	$	—	$	3		$	—		$	3
	Total liabilities	$	—	$	3		$	—		$	3
Table of reconciliation for assets and liablities measured at fair value on a recurring basis using significant unobservable inputs	The following tables present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3).
	Level 3	Balance as of		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 as of		Unrealized gains (losses) on Level 3 assets and liabilities held as of March 31, 2015 recognized in Net income (loss)
	(In millions)	January 1,																Level 3		of Level 3			March 31,
		2015																					2015
	Fixed maturity securities:
	Corporate and other bonds	$	162	$	1		$	—		$	12	$	(12	)	$	(14	)	$	37	$	—		$	186	$	—
	States, municipalities and political subdivisions	94		1			—			—		—			(9		)	—		—			86		—
	Asset-backed:
	Residential mortgage-backed	189		1			—			72		—			(10		)	—		(20		)	232		—
	Commercial mortgage-backed	83		1			1			6		—			(1		)	—		(26		)	64		—
	Other asset-backed	655		1			9			35		(144		)	(3		)	—		—			553		—
	Total asset-backed	927		3			10			113		(144		)	(14		)	—		(46		)	849		—
	Total fixed maturity securities	1,183		5			10			125		(156		)	(37		)	37		(46		)	1,121		—
	Equity securities	16		—			(3		)	—		—			—			—		—			13		—
	Life settlement contracts	82		13			—			—		—			(16		)	—		—			79		1
	Total	$	1,281	$	18		$	7		$	125	$	(156	)	$	(53	)	$	37	$	(46	)	$	1,213	$	1
	Level 3	Balance as of		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 as of		Unrealized gains (losses) on Level 3 assets and liabilities held as of March 31, 2014 recognized in Net income (loss)
	(In millions)	January 1,																Level 3		of Level 3			31-Mar-14
		2014
	Fixed maturity securities:
	Corporate and other bonds	$	204	$	1		$	1		$	5	$	(4	)	$	(5	)	$	3	$	(16	)	$	189	$	—
	States, municipalities and political subdivisions	71		—			1			—		—			—			14		—			86		—
	Asset-backed:
	Residential mortgage-backed	331		1			15			25		—			(21		)	21		(13		)	359		—
	Commercial mortgage-backed	151		1			(1		)	—		—			(1		)	—		(24		)	126		—
	Other asset-backed	446		1			—			148		(83		)	(72		)	—		(1		)	439		—
	Total asset-backed	928		3			14			173		(83		)	(94		)	21		(38		)	924		—
	Total fixed maturity securities	1,203		4			16			178		(87		)	(99		)	38		(54		)	1,199		—
	Equity securities	11		3			(4		)	—		(8		)	—			—		—			2		—
	Life settlement contracts	88		10			—			—		—			(11		)	—		—			87		1
	Separate account business	1		—			—			—		—			—			—		(1		)	—		—
	Total	$	1,303	$	17		$	12		$	178	$	(95	)	$	(110	)	$	38	$	(55	)	$	1,288	$	1
Quantitative information about significant unobservable inputs in the fair value measurement of level 3 assets	The following tables present 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.
	31-Mar-15
	(In millions)	Fair Value		Valuation Technique(s)		Unobservable Input(s)	Range
							(Weighted Average)
	Fixed maturity securities	$	102	Discounted cash flow		Credit spread	2% - 13% (3%)
	Equity securities	13		Market approach		Private offering price	$10 - $4,400 per share ($682)
	Life settlement contracts	79		Discounted cash flow		Discount rate risk premium	9%
						Mortality assumption	55% - 1676% (164%)
	31-Dec-14
	(In millions)	Fair Value		Valuation Technique(s)		Unobservable Input(s)	Range
							(Weighted Average)
	Fixed maturity securities	$	101	Discounted cash flow		Credit spread	2% - 13% (3%)
	Equity securities	16		Market approach		Private offering price	$12 - $4,391 per share ($600)
	Life settlement contracts	82		Discounted cash flow		Discount rate risk premium	9%
						Mortality assumption	55% - 1676% (163%)
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 assets and liabilities which are not measured at fair value on the Condensed Consolidated Balance Sheets are presented in the following tables.
	March 31, 2015	Carrying		Estimated Fair Value
	(In millions)	Amount		Level 1			Level 2			Level 3		Total
	Assets
	Notes receivable for the issuance of common stock	$	1	$	—		$	—		$	1	$	1
	Mortgage loans	586		—			—			612		612
	Liabilities
	Long term debt	$	2,560	$	—		$	2,908		$	—	$	2,908
	December 31, 2014	Carrying		Estimated Fair Value
	(In millions)	Amount		Level 1			Level 2			Level 3		Total
	Assets
	Notes receivable for the issuance of common stock	$	1	$	—		$	—		$	1	$	1
	Mortgage loans	588		—			—			608		608
	Liabilities
	Long term debt	$	2,559	$	—		$	2,883		$	—	$	2,883

Claim_and_Claim_Adjustment_Exp1

Claim and Claim Adjustment Expense Reserves (Tables)	3 Months Ended
	Mar. 31, 2015
Claim and Claim Adjustment Expense Reserves [Abstract]
Net prior year development	The following tables and discussion present net prior year development recorded for Specialty, Commercial, International and Corporate & Other Non-Core segments.
	Three months ended March 31, 2015
	(In millions)	Specialty			Commercial			International			Corporate		Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	2		$	(5	)	$	(4	)	$	—	$	(7	)
	Pretax (favorable) unfavorable premium development	(6		)	(1		)	16			—		9
	Total pretax (favorable) unfavorable net prior year development	$	(4	)	$	(6	)	$	12		$	—	$	2
	Three months ended March 31, 2014
	(In millions)	Specialty			Commercial			International			Corporate		Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(3	)	$	18		$	10		$	—	$	25
	Pretax (favorable) unfavorable premium development	(6		)	(18		)	(7		)	—		(31		)
	Total pretax (favorable) unfavorable net prior year development	$	(9	)	$	—		$	3		$	—	$	(6	)
Net prior year claim and allocated claim adjustment expense reserve development for Specialty segment	The following table presents further detail of the net prior year claim and allocated claim adjustment expense reserve development (development) recorded for the Specialty segment.
	Three months ended March 31
	(In millions)	2015			2014
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Medical Professional Liability	$	14		$	—
	Other Professional Liability and Management Liability	(3		)	(6		)
	Surety	1			1
	Warranty	—			—
	Other	(10		)	2
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	2		$	(3	)
Net prior year claim and allocated claim adjustment expense reserve development for Commercial segment	The following table presents further detail of the development recorded for the Commercial segment.
	Three months ended March 31
	(In millions)	2015			2014
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Commercial Auto	$	—		$	20
	General Liability	4			—
	Workers' Compensation	(1		)	11
	Property and Other	(8		)	(13		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(5	)	$	18
Net prior year claim and allocated claim adjustment expense reserve development for International segment	The following table presents further detail of the development recorded for the International segment.
	Three months ended March 31
	(In millions)	2015			2014
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Medical Professional Liability	$	—		$	1
	Other Professional Liability	—			(1		)
	Liability	(5		)	(2		)
	Property & Marine	(6		)	8
	Other	7			(6		)
	Commutations	—			10
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(4	)	$	10

Benefit_Plans_Tables

Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Components of net periodic cost (benefit)	The components of net periodic cost (benefit) are presented in the following table.
	Three months ended March 31
	(In millions)	2015			2014
	Pension cost (benefit)
	Service cost	$	2		$	3
	Interest cost on projected benefit obligation	28			33
	Expected return on plan assets	(43		)	(48		)
	Amortization of net actuarial loss	9			6
	Net periodic pension cost (benefit)	$	(4	)	$	(6	)
	Postretirement cost (benefit)
	Amortization of prior service credit	$	—		$	(4	)
	Net periodic postretirement cost (benefit)	$	—		$	(4	)

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) by Component (Tables)	3 Months Ended
	Mar. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss) by Component	The following tables present the changes in Accumulated other comprehensive income (loss) by component.
	(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 as of January 1, 2015	$	36		$	942		$	(633	)	$	55		$	400
	Other comprehensive income (loss) before reclassifications	(1		)	121			—			(96		)	24
	Amounts reclassified from Accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $0, $3, $0 and $3	—			9			(6		)	—			3
	Other comprehensive income (loss) after tax (expense) benefit of $0, $(62), $(3), $0 and $(65)	(1		)	112			6			(96		)	21
	Balance as of March 31, 2015	$	35		$	1,054		$	(627	)	$	(41	)	$	421
	(In millions)	Net unrealized gains (losses) on investments with OTTI losses			Net unrealized gains (losses) on other investments			Net unrealized gains (losses) on discontinued operations			Pension and postretirement benefits			Cumulative foreign currency translation adjustment			Total
	Balance as of January 1, 2014	$	26		$	692		$	—		$	(426	)	$	150		$	442
	Transfer to net assets held for sale	(5		)	(17		)	22			—			—			—
	Other comprehensive income (loss) before reclassifications	12			264			8			—			(8		)	276
	Amounts reclassified from Accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(14), $0, $1, $0 and $(13)	—			27			—			(1		)	—			26
	Other comprehensive income (loss) after tax (expense) benefit of $(6), $(127), $(5), $(1), $0 and $(139)	12			237			8			1			(8		)	250
	Balance as of March 31, 2014	$	33		$	912		$	30		$	(425	)	$	142		$	692

Business_Segments_Tables

Business Segments (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Significant components of the Company's continuing operations and selected balance sheet items
	Three months ended March 31, 2015	Specialty			Commercial			International			Life &			Corporate
											Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	680		$	678		$	191		$	138		$	—		$	—		$	1,687
	Net investment income	155			204			14			179			6			—			558
	Other revenues	78			9			—			9			2			(1		)	97
	Total operating revenues	913			891			205			326			8			(1		)	2,342
	Claims, Benefits and Expenses
	Net incurred claims and benefits	429			454			116			340			(4		)	—			1,335
	Policyholders’ dividends	1			3			—			—			—			—			4
	Amortization of deferred acquisition costs	144			117			35			7			—			—			303
	Other insurance related expenses	69			127			37			35			—			—			268
	Other expenses	67			8			5			4			46			(1		)	129
	Total claims, benefits and expenses	710			709			193			386			42			(1		)	2,039
	Operating income (loss) before income tax	203			182			12			(60		)	(34		)	—			303
	Income tax (expense) benefit on operating income (loss)	(68		)	(62		)	(3		)	43			12			—			(78		)
	Net operating income (loss)	135			120			9			(17		)	(22		)	—			225
	Net realized investment gains (losses)	4			4			1			1			—			—			10
	Income tax (expense) benefit on net realized investment gains (losses)	(1		)	(3		)	—			2			—			—			(2		)
	Net realized investment gains (losses), after tax	3			1			1			3			—			—			8
	Net income (loss) from continuing operations	$	138		$	121		$	10		$	(14	)	$	(22	)	$	—		$	233
	March 31, 2015
	(In millions)
	Reinsurance receivables	$	671		$	675		$	207		$	543		$	2,672		$	—		$	4,768
	Insurance receivables	808			1,004			282			13			2			—			2,109
	Deferred acquisition costs	307			225			84			—			—			—			616
	Goodwill	117			—			34			—			—			—			151
	Insurance reserves
	Claim and claim adjustment expenses	6,352			9,441			1,377			3,237			2,841			—			23,248
	Unearned premiums	1,794			1,329			449			139			—			(1		)	3,710
	Future policy benefits	—			—			—			9,747			—			—			9,747
	Three months ended March 31, 2014	Specialty			Commercial			International			Life &			Corporate
											Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	692		$	735		$	241		$	139		$	—		$	(1	)	$	1,806
	Net investment income	144			191			15			171			5			—			526
	Other revenues	68			10			—			5			2			—			85
	Total operating revenues	904			936			256			315			7			(1		)	2,417
	Claims, Benefits and Expenses
	Net incurred claims and benefits	442			568			130			306			(3		)	—			1,443
	Policyholders’ dividends	1			2			—			—			—			—			3
	Amortization of deferred acquisition costs	143			123			55			8			—			—			329
	Other insurance related expenses	65			126			40			32			—			(1		)	262
	Other expenses	61			8			7			1			51			—			128
	Total claims, benefits and expenses	712			827			232			347			48			(1		)	2,165
	Operating income (loss) before income tax	192			109			24			(32		)	(41		)	—			252
	Income tax (expense) benefit on operating income (loss)	(63		)	(35		)	(8		)	30			14			—			(62		)
	Net operating income (loss)	129			74			16			(2		)	(27		)	—			190
	Net realized investment gains (losses)	11			10			3			16			6			—			46
	Income tax (expense) benefit on net realized investment gains (losses)	(3		)	(2		)	(3		)	(6		)	(2		)	—			(16		)
	Net realized investment gains (losses), after tax	8			8			—			10			4			—			30
	Net income (loss) from continuing operations	$	137		$	82		$	16		$	8		$	(23	)	$	—		$	220
	December 31, 2014
	(In millions)
	Reinsurance receivables	$	567		$	690		$	207		$	525		$	2,753		$	—		$	4,742
	Insurance receivables	778			954			250			13			2			—			1,997
	Deferred acquisition costs	304			213			83			—			—			—			600
	Goodwill	117			—			35			—			—			—			152
	Insurance reserves
	Claim and claim adjustment expenses	6,229			9,514			1,441			3,183			2,904			—			23,271
	Unearned premiums	1,763			1,273			431			125			—			—			3,592
Future policy benefits	—			—			—			9,490			—			—			9,490
Policyholders’ funds	9			18			—			—			—			—			27
Revenues by line of business	The following table presents revenue by line of business for each reportable segment. Revenues are comprised of Operating revenues and Net realized investment gains and losses.
	Three months ended March 31
	(In millions)	2015			2014
	Specialty
	Management & Professional Liability	$	697		$	704
	Surety	120			122
	Warranty & Alternative Risks	100			89
	Specialty revenues	917			915
	Commercial
	Middle Market	409			403
	Small Business	165			184
	Other Commercial Insurance	321			359
	Commercial revenues	895			946
	International
	Canada	55			71
	CNA Europe	77			88
	Hardy	74			100
	International revenues	206			259
	Life & Group Non-Core revenues	327			331
	Corporate & Other Non-Core revenues	8			13
	Eliminations	(1		)	(1		)
	Total revenues	$	2,352		$	2,463

Discontinued_Operations_Tables

Discontinued Operations (Tables)	3 Months Ended
	Mar. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Results of discontinued operations	The results of discontinued operations reflected in the Condensed Consolidated Statements of Operations are presented in the following table.
	Three months ended March 31
	(In millions)	2014
	Revenues
	Net investment income	$	41
	Net realized investment gains	1
	Total revenues	42
	Claims, Benefits and Expenses
	Insurance claims and policyholders' benefits	31
	Other operating expenses	1
	Total claims, benefits and expenses	32
	Income before income tax	10
	Income tax expense	(3		)
	Income from operations of discontinued operations, net of income tax	7
	Impairment loss on sale, net of income tax benefit of $41	(214		)
	Loss from discontinued operations	$	(207	)

General_General_Details

General General (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax	$214

Earnings_Per_Share_Narrative_D

Earnings Per Share (Narrative) (Details)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	182	110
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	654	660

Investments_Narrative_Details

Investments (Narrative) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Investments [Abstract]
Reduction of net unrealized gains on investments included in AOCI due to shadow adjustments	$1,370	$1,288
Future capital call commitments for limited partnership investments	338
Mortgage loan commitments	41
Commitments to purchase or fund privately placed debt securities	82
Commitments to sell various privately placed debt securities	$71

Investments_Net_investment_inc

Investments (Net investment income) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Net Investment Income [Line Items]
Gross investment income	$572	$539
Investment expense	-14	-13
Net investment income	558	526
Fixed maturity securities [Member]
Net Investment Income [Line Items]
Gross investment income	443	452
Short term investments [Member]
Net Investment Income [Line Items]
Gross investment income	2	1
Limited partnership investments [Member]
Net Investment Income [Line Items]
Gross investment income	114	73
Equity securities [Member]
Net Investment Income [Line Items]
Gross investment income	3	2
Mortgage loans [Member]
Net Investment Income [Line Items]
Gross investment income	8	6
Trading portfolio [Member]
Net Investment Income [Line Items]
Gross investment income	2	3
Other [Member]
Net Investment Income [Line Items]
Gross investment income	$0	$2

Investments_Net_realized_inves

Investments (Net realized investment gains (losses)) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Net realized investment gains (losses)	$10	$46
Fixed maturity securities [Member]
Gross realized gains	33	53
Gross realized losses	-21	-15
Net realized investment gains (losses)	12	38
Equity securities [Member]
Gross realized gains	1	5
Gross realized losses	-1	0
Net realized investment gains (losses)	0	5
Derivative [Member]
Net realized investment gains (losses)	-1	0
Short term investments and other [Member]
Net realized investment gains (losses)	($1)	$3

Investments_Components_of_othe

Investments (Components of other-than-temporary impairment losses recognized in earnings) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Other-than-temporary impairment losses recognized in earnings	$12	$2
Corporate and other bonds [Member]
Other-than-temporary impairment losses recognized in earnings	5	1
States, municipalities and political subdivisions [Member]
Other-than-temporary impairment losses recognized in earnings	5	0
Residential mortgage-backed [Member]
Other-than-temporary impairment losses recognized in earnings	1	1
Total fixed maturity securities available-for-sale [Member]
Other-than-temporary impairment losses recognized in earnings	11	2
Common stock [Member]
Other-than-temporary impairment losses recognized in earnings	$1	$0

Investments_Summary_of_fixed_m

Investments (Summary of fixed maturity and equity securities) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Cost or Amortized Cost	$37,088	$37,545
Gross Unrealized Gain	3,817	3,544
Gross Unrealized Loss	75	99
Estimated fair value	40,830	40,990
Corporate and other bonds [Member]
Cost or Amortized Cost	16,721	17,210
Gross Unrealized Gain	1,867	1,721
Gross Unrealized Loss	43	61
Estimated fair value	18,545	18,870
Unrealized OTTI Losses (Gains)	0	0
States, municipalities and political subdivisions [Member]
Cost or Amortized Cost	11,407	11,285
Gross Unrealized Gain	1,536	1,463
Gross Unrealized Loss	9	8
Estimated fair value	12,934	12,740
Unrealized OTTI Losses (Gains)	0	0
Residential mortgage-backed [Member]
Cost or Amortized Cost	4,998	5,028
Gross Unrealized Gain	241	218
Gross Unrealized Loss	13	13
Estimated fair value	5,226	5,233
Unrealized OTTI Losses (Gains)	-51	-53
Commercial mortgage-backed [Member]
Cost or Amortized Cost	2,151	2,056
Gross Unrealized Gain	114	93
Gross Unrealized Loss	5	5
Estimated fair value	2,260	2,144
Unrealized OTTI Losses (Gains)	-3	-2
Other asset-backed [Member]
Cost or Amortized Cost	1,109	1,234
Gross Unrealized Gain	15	11
Gross Unrealized Loss	1	10
Estimated fair value	1,123	1,235
Unrealized OTTI Losses (Gains)	0	0
Total asset-backed [Member]
Cost or Amortized Cost	8,258	8,318
Gross Unrealized Gain	370	322
Gross Unrealized Loss	19	28
Estimated fair value	8,609	8,612
Unrealized OTTI Losses (Gains)	-54	-55
U.S. Treasury and obligations of government-sponsored enterprises [Member]
Cost or Amortized Cost	24	26
Gross Unrealized Gain	6	5
Gross Unrealized Loss	0	0
Estimated fair value	30	31
Unrealized OTTI Losses (Gains)	0	0
Foreign Government Debt Securities [Member]
Cost or Amortized Cost	390	438
Gross Unrealized Gain	19	16
Gross Unrealized Loss	0	0
Estimated fair value	409	454
Unrealized OTTI Losses (Gains)	0	0
Redeemable preferred stock [Member]
Cost or Amortized Cost	39	39
Gross Unrealized Gain	3	3
Gross Unrealized Loss	0	0
Estimated fair value	42	42
Unrealized OTTI Losses (Gains)	0	0
Total fixed maturity securities available-for-sale [Member]
Cost or Amortized Cost	36,839	37,316
Gross Unrealized Gain	3,801	3,530
Gross Unrealized Loss	71	97
Estimated fair value	40,569	40,749
Unrealized OTTI Losses (Gains)	-54	-55
Total fixed maturity securities trading [Member]
Cost or Amortized Cost, Trading Securities	36	19
Estimated Fair Value, Trading Securities	36	19
Common stock [Member]
Cost or Amortized Cost	41	38
Gross Unrealized Gain	9	9
Gross Unrealized Loss	0	0
Estimated fair value	50	47
Preferred stock [Member]
Cost or Amortized Cost	172	172
Gross Unrealized Gain	7	5
Gross Unrealized Loss	4	2
Estimated fair value	175	175
Total equity securities available-for-sale [Member]
Cost or Amortized Cost	213	210
Gross Unrealized Gain	16	14
Gross Unrealized Loss	4	2
Estimated fair value	$225	$222

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
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance of credit losses on fixed maturity securities	$62	$74
Reductions for securities sold during the period	-1	-2
Reductions for securities the Company intends to sell or more likely than not will be required to sell	0	-3
Ending balance of credit losses on fixed maturity securities	$61	$69

Investments_Securities_in_a_gr

Investments (Securities in a gross unrealized loss position) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	$2,030	$2,855
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	50	70
Estimated Fair Value, 12 Months or Longer	455	707
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	25	29
Estimated Fair Value, Total	2,485	3,562
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	75	99
Corporate and other bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	840	1,330
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	31	46
Estimated Fair Value, 12 Months or Longer	139	277
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	12	15
Estimated Fair Value, Total	979	1,607
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	43	61
States, municipalities and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	479	335
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	6	5
Estimated Fair Value, 12 Months or Longer	100	127
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	3	3
Estimated Fair Value, Total	579	462
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	9	8
Residential mortgage-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	318	293
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	5	5
Estimated Fair Value, 12 Months or Longer	148	189
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	8	8
Estimated Fair Value, Total	466	482
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	13	13
Commercial mortgage-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	175	264
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	3	2
Estimated Fair Value, 12 Months or Longer	62	99
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	2	3
Estimated Fair Value, Total	237	363
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	5	5
Other asset-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	187	607
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1	10
Estimated Fair Value, 12 Months or Longer	5	7
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Estimated Fair Value, Total	192	614
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1	10
Total asset-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	680	1,164
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	9	17
Estimated Fair Value, 12 Months or Longer	215	295
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	10	11
Estimated Fair Value, Total	895	1,459
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	19	28
U.S. Treasury and obligations of government-sponsored enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	3	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Estimated Fair Value, 12 Months or Longer	0	4
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Estimated Fair Value, Total	3	7
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	0
Foreign Government Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	13	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Estimated Fair Value, 12 Months or Longer	1	3
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Estimated Fair Value, Total	14	6
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	0
Redeemable preferred stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months		3
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0
Estimated Fair Value, 12 Months or Longer		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0
Estimated Fair Value, Total		3
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		0
Total fixed maturity securities available-for-sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	2,015	2,838
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	46	68
Estimated Fair Value, 12 Months or Longer	455	706
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	25	29
Estimated Fair Value, Total	2,470	3,544
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	71	97
Preferred stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	15	17
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	4	2
Estimated Fair Value, 12 Months or Longer	0	1
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Estimated Fair Value, Total	15	18
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$4	$2

Investments_Contractual_maturi

Investments (Contractual maturity) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Investments [Abstract]
Due in one year or less, cost or amortized cost	$2,011	$2,479
Due after one year through five years, cost or amortized cost	8,760	9,054
Due after five years through ten years, cost or amortized cost	12,401	12,055
Due after ten years, cost or amortized cost	13,667	13,728
Total Amortized Cost Basis	36,839	37,316
Due in one year or less, estimated fair value	2,043	2,511
Due after one year through five years, estimated fair value	9,340	9,605
Due after five years through ten years, estimated fair value	13,108	12,584
Due after ten years, estimated fair value	16,078	16,049
Total Estimated Fair Value	$40,569	$40,749

Investments_Derivative_Financi

Investments Derivative Financial Instruments (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Derivative [Line Items]
Estimated fair value asset	$2	$0
Estimated fair value liability	5	3
Not Designated as Hedging Instrument [Member] | Currency forwards [Member]
Derivative [Line Items]
Derivative, Notional Amount	18	9
Estimated fair value asset	2	0
Estimated fair value liability	0	0
Not Designated as Hedging Instrument [Member] | Equity warrants [Member]
Derivative [Line Items]
Derivative, Notional Amount	5	5
Estimated fair value asset	0	0
Estimated fair value liability	0	0
Not Designated as Hedging Instrument [Member] | Embedded Derivative Financial Instruments [Member]
Derivative [Line Items]
Derivative, Notional Amount	184	184
Estimated fair value asset	0	0
Estimated fair value liability	$5	$3

Fair_Value_Assets_and_liabilit

Fair Value (Assets and liabilities measured at fair value on a recurring basis) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	$42,372	$42,757
Fair value of liabilities, measured on a recurring basis	5	3
Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	18,552	18,889
States, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	12,963	12,740
Residential mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	5,226	5,233
Commercial mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	2,260	2,144
Other asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,123	1,235
Total asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	8,609	8,612
U.S. Treasury and obligations of government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	30	31
Foreign Government Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	409	454
Redeemable preferred stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	42	42
Fixed maturity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	40,605	40,768
Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	225	222
Derivative Financial Instruments, Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	2
Other invested assets, excluding derivative financial instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	41	41
Short term investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,420	1,644
Life settlement contracts, included in Other assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	79	82
Embedded Derivative Financial Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities, measured on a recurring basis	5	3
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,016	957
Fair value of liabilities, measured on a recurring basis	0	0
Level 1 [Member] | Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	29	32
Level 1 [Member] | States, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 1 [Member] | Residential mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 1 [Member] | Commercial mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 1 [Member] | Other asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 1 [Member] | Total asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
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]
Fair value of assets, measured on a recurring basis	29	28
Level 1 [Member] | Foreign Government Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	37	41
Level 1 [Member] | Redeemable preferred stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	30	30
Level 1 [Member] | Fixed maturity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	125	131
Level 1 [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	149	145
Level 1 [Member] | Derivative Financial Instruments, Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0
Level 1 [Member] | Other invested assets, excluding derivative financial instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 1 [Member] | Short term investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	742	681
Level 1 [Member] | Life settlement contracts, included in Other assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 1 [Member] | Embedded Derivative Financial Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities, measured on a recurring basis	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	40,143	40,519
Fair value of liabilities, measured on a recurring basis	5	3
Level 2 [Member] | Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	18,337	18,695
Level 2 [Member] | States, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	12,877	12,646
Level 2 [Member] | Residential mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	4,994	5,044
Level 2 [Member] | Commercial mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	2,196	2,061
Level 2 [Member] | Other asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	570	580
Level 2 [Member] | Total asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	7,760	7,685
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]
Fair value of assets, measured on a recurring basis	1	3
Level 2 [Member] | Foreign Government Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	372	413
Level 2 [Member] | Redeemable preferred stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	12	12
Level 2 [Member] | Fixed maturity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	39,359	39,454
Level 2 [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	63	61
Level 2 [Member] | Derivative Financial Instruments, Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	2
Level 2 [Member] | Other invested assets, excluding derivative financial instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	41	41
Level 2 [Member] | Short term investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	678	963
Level 2 [Member] | Life settlement contracts, included in Other assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 2 [Member] | Embedded Derivative Financial Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities, measured on a recurring basis	5	3
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,213	1,281
Fair value of liabilities, measured on a recurring basis	0	0
Level 3 [Member] | Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	186	162
Level 3 [Member] | States, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	86	94
Level 3 [Member] | Residential mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	232	189
Level 3 [Member] | Commercial mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	64	83
Level 3 [Member] | Other asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	553	655
Level 3 [Member] | Total asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	849	927
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]
Fair value of assets, measured on a recurring basis	0	0
Level 3 [Member] | Foreign Government Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 3 [Member] | Redeemable preferred stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 3 [Member] | Fixed maturity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,121	1,183
Level 3 [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	13	16
Level 3 [Member] | Derivative Financial Instruments, Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0
Level 3 [Member] | Other invested assets, excluding derivative financial instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis		0
Level 3 [Member] | Short term investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 3 [Member] | Life settlement contracts, included in Other assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	79	82
Level 3 [Member] | Embedded Derivative Financial Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities, measured on a recurring basis	$0	$0

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
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	$1,281	$1,303
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	18	17
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	7	12
Purchases	125	178
Sales	-156	-95
Settlements	-53	-110
Transfers into Level 3	37	38
Transfers out of Level 3	-46	-55
Balance, Ending, Assets	1,213	1,288
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	1	1
Fixed maturity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	1,183	1,203
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	5	4
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	10	16
Purchases	125	178
Sales	-156	-87
Settlements	-37	-99
Transfers into Level 3	37	38
Transfers out of Level 3	-46	-54
Balance, Ending, Assets	1,121	1,199
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	0	0
Corporate and other bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	162	204
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)	0	1
Purchases	12	5
Sales	-12	-4
Settlements	-14	-5
Transfers into Level 3	37	3
Transfers out of Level 3	0	-16
Balance, Ending, Assets	186	189
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	0	0
States, municipalities and political subdivisions [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	94	71
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	1	0
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	0	1
Purchases	0	0
Sales	0	0
Settlements	-9	0
Transfers into Level 3	0	14
Transfers out of Level 3	0	0
Balance, Ending, Assets	86	86
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	0	0
Residential mortgage-backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	189	331
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)	0	15
Purchases	72	25
Sales	0	0
Settlements	-10	-21
Transfers into Level 3	0	21
Transfers out of Level 3	-20	-13
Balance, Ending, Assets	232	359
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	0	0
Commercial Mortgage Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	83	151
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
Purchases	6	0
Sales	0	0
Settlements	-1	-1
Transfers into Level 3	0	0
Transfers out of Level 3	-26	-24
Balance, Ending, Assets	64	126
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	0	0
Other asset-backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	655	446
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)	9	0
Purchases	35	148
Sales	-144	-83
Settlements	-3	-72
Transfers into Level 3	0	0
Transfers out of Level 3	0	-1
Balance, Ending, Assets	553	439
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	0	0
Total asset-backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	927	928
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	3	3
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	10	14
Purchases	113	173
Sales	-144	-83
Settlements	-14	-94
Transfers into Level 3	0	21
Transfers out of Level 3	-46	-38
Balance, Ending, Assets	849	924
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	0	0
Equity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	16	11
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	0	3
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-3	-4
Purchases	0	0
Sales	0	-8
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, Ending, Assets	13	2
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	0	0
Life settlement contracts, included in Other assets [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	82	88
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	13	10
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	0	0
Purchases	0	0
Sales	0	0
Settlements	-16	-11
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, Ending, Assets	79	87
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	1	1
Separate account business [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets		1
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)		0
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)		0
Purchases		0
Sales		0
Settlements		0
Transfers into Level 3		0
Transfers out of Level 3		-1
Balance, Ending, Assets		0
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)		$0

Fair_Value_Quantitative_inform

Fair Value (Quantitative information about significant unobservable inputs in the fair value measurement of level 3 assets) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
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	$102	$101
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Credit Spread	2.00%	2.00%
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Credit Spread	13.00%	13.00%
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Credit Spread	3.00%	3.00%
Equity securities [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	13	16
Equity securities [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price	$10	$12
Equity securities [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price	$4,400	$4,391
Equity securities [Member] | Market Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price	$682	$600
Life settlement contracts, included in Other assets [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	$79	$82
Life settlement contracts, included in Other assets [Member] | Income Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality assumption	55.00%	55.00%
Life settlement contracts, included in Other assets [Member] | Income Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality assumption	1676.00%	1676.00%
Life settlement contracts, included in Other assets [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality assumption	164.00%	163.00%
Life settlement contracts, included in Other assets [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_Narrative_Details

Fair Value (Narrative) (Details) (USD $)	Mar. 31, 2015	Mar. 31, 2014
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	$0	$23
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$0	$1

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 $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	$1	$1
Mortgage loans	586	588
Financial Liabilities [Abstract]
Long term debt	2,560	2,559
Carrying Amount [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	1	1
Mortgage loans	586	588
Financial Liabilities [Abstract]
Long term debt	2,560	2,559
Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	1	1
Mortgage loans	612	608
Financial Liabilities [Abstract]
Long term debt	2,908	2,883
Level 1 [Member] | Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	0	0
Mortgage loans	0	0
Financial Liabilities [Abstract]
Long term debt	0	0
Level 2 [Member] | Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	0	0
Mortgage loans	0	0
Financial Liabilities [Abstract]
Long term debt	2,908	2,883
Level 3 [Member] | Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	1	1
Mortgage loans	612	608
Financial Liabilities [Abstract]
Long term debt	$0	$0

Claim_and_Claim_Adjustment_Exp2

Claim and Claim Adjustment Expense Reserves (Narrative) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Claim and Claim Adjustment Expense Reserves [Abstract]
Catastrophe losses net of reinsurance	$29	$74

Claim_and_Claim_Adjustment_Exp3

Claim and Claim Adjustment Expense Reserves (Net prior year development) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($7)	$25
Pretax (favorable) unfavorable premium development, excluding Life & Group	9	-31
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	2	-6
Specialty [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
Pretax (favorable) unfavorable premium development, excluding Life & Group	-6	-6
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-4	-9
Commercial [Member]
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	-5	18
Pretax (favorable) unfavorable premium development, excluding Life & Group	-1	-18
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-6	0
International [Member]
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	-4	10
Pretax (favorable) unfavorable premium development, excluding Life & Group	16	-7
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	12	3
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	0	0
Pretax (favorable) unfavorable premium development, excluding Life & Group	0	0
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	$0	$0

Claim_and_Claim_Adjustment_Exp4

Claim and Claim Adjustment Expense Reserves (Net prior year claim and allocated claim adjustment expense reserve development for Specialty segment) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($7)	$25
Specialty [Member]
Medical Professional Liability	14	0
Other Professional Liability and Management Liability	-3	-6
Surety	1	1
Warranty	0	0
Other	-10	2
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	$2	($3)

Claim_and_Claim_Adjustment_Exp5

Claim and Claim Adjustment Expense Reserves (Net prior year claim and allocated claim adjustment expense reserve development for Commercial segment) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($7)	$25
Commercial [Member]
Commercial Auto	0	20
General Liability	4	0
Workers' Compensation	-1	11
Property and Other	-8	-13
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($5)	$18

Claim_and_Claim_Adjustment_Exp6

Claim and Claim Adjustment Expense Reserves Net prior year claim and allocated claim adjustment expense reserve development for International segment (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($7)	$25
International [Member]
Medical Professional Liability	0	1
Other Professional Liability	0	-1
Liability	-5	-2
Property & Marine	-6	8
Other	7	-6
Commutations	0	10
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($4)	$10

Benefit_Plans_Components_of_ne

Benefit Plans (Components of net periodic cost (benefit)) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$2	$3
Interest cost on projected benefit obligation	28	33
Expected return on plan assets	-43	-48
Amortization of net actuarial (gain) loss	9	6
Net periodic (benefit) cost	-4	-6
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service credit	0	-4
Net periodic (benefit) cost	$0	($4)

Commitments_Contingencies_and_1

Commitments, Contingencies, and Guarantees (Narrative) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Property Lease Guarantee [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$41
Guarantee and indemnification agreements [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Current Carrying Value	5	5
Guarantee Obligations [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	375
Indemnification Agreement [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	324
Structured settlement annuities [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$2,000

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) by Component (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	$400	$442
Transfer to net assets held for sale		0
Other comprehensive income (loss), before reclassifications	24	276
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	3	26
Other comprehensive income (loss) after tax (expense) benefit	21	250
Accumulated other comprehensive income (loss), ending balance	421	692
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	3	-13
Tax (expense) benefit on other comprehensive income (loss)	-65	-139
Net unrealized gains (losses) on investments with OTTI losses [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	36	26
Transfer to net assets held for sale		-5
Other comprehensive income (loss), before reclassifications	-1	12
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	0	0
Other comprehensive income (loss) after tax (expense) benefit	-1	12
Accumulated other comprehensive income (loss), ending balance	35	33
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	0	0
Tax (expense) benefit on other comprehensive income (loss)	0	-6
Net unrealized gains (losses) on other investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	942	692
Transfer to net assets held for sale		-17
Other comprehensive income (loss), before reclassifications	121	264
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	9	27
Other comprehensive income (loss) after tax (expense) benefit	112	237
Accumulated other comprehensive income (loss), ending balance	1,054	912
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	0	-14
Tax (expense) benefit on other comprehensive income (loss)	-62	-127
Accumulated Net Unrealized Gains Losses on discontinued operations [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance		0
Transfer to net assets held for sale		22
Other comprehensive income (loss), before reclassifications		8
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit		0
Other comprehensive income (loss) after tax (expense) benefit		8
Accumulated other comprehensive income (loss), ending balance		30
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)		0
Tax (expense) benefit on other comprehensive income (loss)		-5
Pension and postretirement benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	-633	-426
Transfer to net assets held for sale		0
Other comprehensive income (loss), before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	-6	-1
Other comprehensive income (loss) after tax (expense) benefit	6	1
Accumulated other comprehensive income (loss), ending balance	-627	-425
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	3	1
Tax (expense) benefit on other comprehensive income (loss)	-3	-1
Cumulative foreign currency translation adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	55	150
Transfer to net assets held for sale		0
Other comprehensive income (loss), before reclassifications	-96	-8
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	0	0
Other comprehensive income (loss) after tax (expense) benefit	-96	-8
Accumulated other comprehensive income (loss), ending balance	-41	142
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	0	0
Tax (expense) benefit on other comprehensive income (loss)	$0	$0

Business_Segments_Income_State

Business Segments (Income Statement Information) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating Revenues
Net earned premiums	$1,687	$1,806
Net investment income	558	526
Other revenues	97	85
Total operating revenues	2,342	2,417
Claims, Benefits and Expenses
Net incurred claims and benefits	1,335	1,443
Policyholders' dividends	4	3
Amortization of deferred acquisition costs	303	329
Other insurance related expenses	268	262
Other expenses	129	128
Total claims, benefits and expenses	2,039	2,165
Operating income (loss) before income tax	303	252
Income tax (expense) benefit on operating income (loss)	-78	-62
Net operating income (loss)	225	190
Net realized investment gains (losses), pre-tax	10	46
Income tax (expense) benefit on net realized investment gains (losses)	-2	-16
Net realized investment gains (losses), after tax	8	30
Net income (loss) from continuing operations	233	220
Specialty [Member]
Operating Revenues
Net earned premiums	680	692
Net investment income	155	144
Other revenues	78	68
Total operating revenues	913	904
Claims, Benefits and Expenses
Net incurred claims and benefits	429	442
Policyholders' dividends	1	1
Amortization of deferred acquisition costs	144	143
Other insurance related expenses	69	65
Other expenses	67	61
Total claims, benefits and expenses	710	712
Operating income (loss) before income tax	203	192
Income tax (expense) benefit on operating income (loss)	-68	-63
Net operating income (loss)	135	129
Net realized investment gains (losses), pre-tax	4	11
Income tax (expense) benefit on net realized investment gains (losses)	-1	-3
Net realized investment gains (losses), after tax	3	8
Net income (loss) from continuing operations	138	137
Commercial [Member]
Operating Revenues
Net earned premiums	678	735
Net investment income	204	191
Other revenues	9	10
Total operating revenues	891	936
Claims, Benefits and Expenses
Net incurred claims and benefits	454	568
Policyholders' dividends	3	2
Amortization of deferred acquisition costs	117	123
Other insurance related expenses	127	126
Other expenses	8	8
Total claims, benefits and expenses	709	827
Operating income (loss) before income tax	182	109
Income tax (expense) benefit on operating income (loss)	-62	-35
Net operating income (loss)	120	74
Net realized investment gains (losses), pre-tax	4	10
Income tax (expense) benefit on net realized investment gains (losses)	-3	-2
Net realized investment gains (losses), after tax	1	8
Net income (loss) from continuing operations	121	82
International [Member]
Operating Revenues
Net earned premiums	191	241
Net investment income	14	15
Other revenues	0	0
Total operating revenues	205	256
Claims, Benefits and Expenses
Net incurred claims and benefits	116	130
Policyholders' dividends	0	0
Amortization of deferred acquisition costs	35	55
Other insurance related expenses	37	40
Other expenses	5	7
Total claims, benefits and expenses	193	232
Operating income (loss) before income tax	12	24
Income tax (expense) benefit on operating income (loss)	-3	-8
Net operating income (loss)	9	16
Net realized investment gains (losses), pre-tax	1	3
Income tax (expense) benefit on net realized investment gains (losses)	0	-3
Net realized investment gains (losses), after tax	1	0
Net income (loss) from continuing operations	10	16
Life and Group Non-Core [Member]
Operating Revenues
Net earned premiums	138	139
Net investment income	179	171
Other revenues	9	5
Total operating revenues	326	315
Claims, Benefits and Expenses
Net incurred claims and benefits	340	306
Policyholders' dividends	0	0
Amortization of deferred acquisition costs	7	8
Other insurance related expenses	35	32
Other expenses	4	1
Total claims, benefits and expenses	386	347
Operating income (loss) before income tax	-60	-32
Income tax (expense) benefit on operating income (loss)	43	30
Net operating income (loss)	-17	-2
Net realized investment gains (losses), pre-tax	1	16
Income tax (expense) benefit on net realized investment gains (losses)	2	-6
Net realized investment gains (losses), after tax	3	10
Net income (loss) from continuing operations	-14	8
Corporate and Other Non-Core [Member]
Operating Revenues
Net earned premiums	0	0
Net investment income	6	5
Other revenues	2	2
Total operating revenues	8	7
Claims, Benefits and Expenses
Net incurred claims and benefits	-4	-3
Policyholders' dividends	0	0
Amortization of deferred acquisition costs	0	0
Other insurance related expenses	0	0
Other expenses	46	51
Total claims, benefits and expenses	42	48
Operating income (loss) before income tax	-34	-41
Income tax (expense) benefit on operating income (loss)	12	14
Net operating income (loss)	-22	-27
Net realized investment gains (losses), pre-tax	0	6
Income tax (expense) benefit on net realized investment gains (losses)	0	-2
Net realized investment gains (losses), after tax	0	4
Net income (loss) from continuing operations	-22	-23
Eliminations [Member]
Operating Revenues
Net earned premiums	0	-1
Net investment income	0	0
Other revenues	-1	0
Total operating revenues	-1	-1
Claims, Benefits and Expenses
Net incurred claims and benefits	0	0
Policyholders' dividends	0	0
Amortization of deferred acquisition costs	0	0
Other insurance related expenses	0	-1
Other expenses	-1	0
Total claims, benefits and expenses	-1	-1
Operating income (loss) before income tax	0	0
Income tax (expense) benefit on operating income (loss)	0	0
Net operating income (loss)	0	0
Net realized investment gains (losses), pre-tax	0	0
Income tax (expense) benefit on net realized investment gains (losses)	0	0
Net realized investment gains (losses), after tax	0	0
Net income (loss) from continuing operations	$0	$0

Business_Segments_Balance_Shee

Business Segments (Balance Sheet Information) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Segment Reporting Information [Line Items]
Reinsurance receivables	$4,768	$4,742
Insurance receivables	2,109	1,997
Deferred acquisition costs	616	600
Goodwill	151	152
Insurance reserves
Claim and claim adjustment expenses	23,248	23,271
Unearned premiums	3,710	3,592
Future policy benefits	9,747	9,490
Policyholders’ funds	0	27
Specialty [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	671	567
Insurance receivables	808	778
Deferred acquisition costs	307	304
Goodwill	117	117
Insurance reserves
Claim and claim adjustment expenses	6,352	6,229
Unearned premiums	1,794	1,763
Future policy benefits	0	0
Policyholders’ funds		9
Commercial [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	675	690
Insurance receivables	1,004	954
Deferred acquisition costs	225	213
Goodwill	0	0
Insurance reserves
Claim and claim adjustment expenses	9,441	9,514
Unearned premiums	1,329	1,273
Future policy benefits	0	0
Policyholders’ funds		18
International [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	207	207
Insurance receivables	282	250
Deferred acquisition costs	84	83
Goodwill	34	35
Insurance reserves
Claim and claim adjustment expenses	1,377	1,441
Unearned premiums	449	431
Future policy benefits	0	0
Policyholders’ funds		0
Life and Group Non-Core [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	543	525
Insurance receivables	13	13
Deferred acquisition costs	0	0
Goodwill	0	0
Insurance reserves
Claim and claim adjustment expenses	3,237	3,183
Unearned premiums	139	125
Future policy benefits	9,747	9,490
Policyholders’ funds		0
Corporate and Other Non-Core [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	2,672	2,753
Insurance receivables	2	2
Deferred acquisition costs	0	0
Goodwill	0	0
Insurance reserves
Claim and claim adjustment expenses	2,841	2,904
Unearned premiums	0	0
Future policy benefits	0	0
Policyholders’ funds		0
Eliminations [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	0	0
Insurance receivables	0	0
Deferred acquisition costs	0	0
Goodwill	0	0
Insurance reserves
Claim and claim adjustment expenses	0	0
Unearned premiums	-1	0
Future policy benefits	0	0
Policyholders’ funds		$0

Business_Segments_Revenues_by_

Business Segments (Revenues by Line of Business) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues	$2,352	$2,463
Specialty [Domain]
Revenues	917	915
Management & Professional Liability [Member]
Revenues	697	704
Surety [Member]
Revenues	120	122
Warranty & Alternative Risks [Member]
Revenues	100	89
Commercial [Domain]
Revenues	895	946
Middle Markets [Member]
Revenues	409	403
Small Business [Member]
Revenues	165	184
Other Commercial Insurance [Member]
Revenues	321	359
International [Domain]
Revenues	206	259
Canada [Member]
Revenues	55	71
CNA Europe [Member]
Revenues	77	88
Hardy [Member]
Revenues	74	100
Life & Group Non-Core [Domain]
Revenues	327	331
Corporate and Other [Domain]
Revenues	8	13
Intersegment Eliminations [Domain]
Revenues	($1)	($1)

Discontinued_Operations_Income

Discontinued Operations Income Statement Information (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues
Net Investment Income		$41
Net Realized Investment Gains (Losses)		1
Total Revenues		42
Claims, Benefits and Expenses
Insurance Claims and Policyholders' Benefits		31
Other Operating Expenses		1
Total Claims, Benefits and Expenses		32
Income before Income Tax		10
Income tax (expense) benefit		-3
Income from operations of discontinued operations, net of income tax		7
Impairment loss on sale, net of income tax benefit		-214
Income (Loss) from Discontinued Operations	0	-207
Income tax benefit (expense) on impairment		$41