CNA Financial (CNA) 10-Q 29 Apr 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document	3 Months Ended
	Mar. 31, 2014	Apr. 25, 2014
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'CNA FINANCIAL CORP	'
Entity Central Index Key	'0000021175	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	269,924,573

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Revenues	'	'
Net earned premiums	$1,806	$1,764
Net investment income	526	591
Net realized investment gains (losses):	'	'
Other-than-temporary impairment losses	-2	-18
Portion of other-than-temporary impairments recognized in Other comprehensive income (losses)	'	'
Net other-than-temporary impairment losses recognized in earnings	-2	-18
Other net realized investment gains (losses)	48	41
Net realized investment gains (losses)	46	23
Other revenues	85	77
Total revenues	2,463	2,455
Claims, Benefits and Expenses	'	'
Insurance claims and policyholders’ benefits	1,446	1,396
Amortization of deferred acquisition costs	329	328
Other operating expenses	346	340
Interest	44	42
Total claims, benefits and expenses	2,165	2,106
Income from continuing operations before income tax	298	349
Income tax (expense) benefit	-78	-108
Income (loss) from continuing operations	220	241
Income (loss) from discontinued operations, net of income tax benefit (expense) of $38 and $(5)	-207	9
Net income (loss)	$13	$250
Basic Earnings (Loss) Per Share	'	'
Income (Loss) from Continuing Operations	$0.82	$0.89
Income (Loss) from Discontinued Operations	($0.77)	$0.04
Basic earnings per share	$0.05	$0.93
Diluted Earnings (Loss) Per Share	'	'
Income (Loss) from Continuing Operations	$0.81	$0.89
Income (Loss) from Discontinued Operations	($0.76)	$0.04
Diluted earnings per share	$0.05	$0.93
Dividends per share	$1.25	$0.20
Weighted Average Outstanding Common Stock and Common Stock Equivalents	'	'
Basic	269.8	269.5
Diluted	270.5	269.9

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Operations (Unaudited) (Parentheticals) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]	'	'
Income tax (expense) benefit on discontinued operations	$38	($5)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Other Comprehensive Income (Loss), Net of Tax, Changes In:	'	'
Net unrealized gains (losses) on investments with other-than-temporary impairments	$12	$14
Net unrealized gains (losses) on other investments	237	-62
Net unrealized gains (losses) on investments	249	-48
Net unrealized gains (losses) on discontinued operations	8	'
Foreign currency translation adjustment	-8	-61
Pension and postretirement benefits	1	5
Other comprehensive income (loss), net of tax	250	-104
Net income (loss)	13	250
Total comprehensive income (loss)	$263	$146

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets	'	'
Fixed maturity securities at fair value (amortized cost of $36,913 and $39,311)	$39,415	$41,233
Equity securities at fair value (cost of $163 and $179)	174	185
Limited partnership investments	2,799	2,720
Other invested assets	55	54
Mortgage loans	495	508
Short term investments	2,070	1,407
Total investments	45,008	46,107
Cash	206	195
Reinsurance receivables (less allowance for uncollectible receivables of $65 and $71)	5,034	6,017
Insurance receivables (less allowance for uncollectible receivables of $82 and $84)	2,050	1,979
Accrued investment income	437	443
Deferred acquisition costs	652	624
Deferred income taxes	48	220
Property and equipment at cost (less accumulated depreciation of $367 and $365)	293	304
Goodwill	155	155
Assets held for sale	3,486	'
Other assets	855	969
Separate account business	'	181
Total assets	58,224	57,194
Liabilities	'	'
Claim and claim adjustment expenses	23,933	24,089
Unearned premiums	3,838	3,718
Future policy benefits	8,254	10,471
Policyholders’ funds	26	116
Short term debt	549	549
Long term debt	2,558	2,011
Liabilities held for sale	3,250	'
Other liabilities (includes $3 and $178 due to Loews Corporation)	3,234	3,408
Separate account business	'	181
Total liabilities	45,642	44,543
Commitments and contingencies (Notes C, G and J)	'	'
Stockholders' Equity	'	'
Common stock ($2.50 par value; 500,000,000 shares authorized; 273,040,243 shares issued; 269,923,905 and 269,717,583 shares outstanding)	683	683
Additional paid-in capital	2,144	2,145
Retained earnings	9,170	9,495
Accumulated other comprehensive income (loss)	692	442
Treasury stock (3,116,338 and 3,322,660 shares), at cost	-85	-91
Notes receivable for the issuance of common stock	-22	-23
Total stockholders’ equity	12,582	12,651
Total liabilities and stockholders' equity	$58,224	$57,194

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Fixed maturities securities at amortized cost	$36,913	$39,311
Equity securities at cost	163	179
Allowance for uncollectible reinsurance receivables	65	71
Allowance for uncollectible insurance receivables	82	84
Accumulated depreciation on property and equipment	367	365
Other liabilities payable to Loews Corporation	$3	$178
Common stock, par value	$2.50	$2.50
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	273,040,243	273,040,243
Common stock, shares outstanding	269,923,905	269,717,583
Treasury stock, shares	3,116,338	3,322,660

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Cash Flows from Operating Activities	'	'
Net income (loss)	$13	$250
Adjustments to reconcile net income (loss) to net cash flows provided (used) by operating activities:	'	'
Impairment loss on pending sale of subsidiary	255	'
Deferred income tax expense (benefit)	25	99
Trading portfolio activity	21	-48
Net realized investment gains	47	28
Equity method investees	132	-91
Amortization of investments	-1	-10
Depreciation and amortization	20	33
Changes in:	'	'
Receivables, net	126	-20
Accrued investment income	-36	-42
Deferred acquisition costs	-21	-40
Insurance reserves	85	79
Other assets	-35	-20
Other liabilities	-372	16
Other, net	3	13
Total adjustments	155	-59
Net cash flows provided (used) by operating activities	168	191
Dispositions:	'	'
Fixed maturity securities - sales	1,550	1,409
Fixed maturity securities - maturities, calls and redemptions	851	866
Equity securities	11	51
Limited partnerships	68	58
Mortgage loans	13	1
Purchases:	'	'
Fixed maturity securities	-2,072	-2,720
Equity securities	-5	-12
Limited partnerships	-73	-41
Mortgage loans	'	-25
Change in other investments	'	3
Change in short term investments	-688	264
Purchases of property and equipment	-10	-21
Other, net	1	6
Net cash flows provided (used) by investing activities	-354	-161
Cash Flows from Financing Activities	'	'
Dividends paid to common stockholders	-338	-55
Proceeds from issuance of debt	546	'
Stock options exercised	4	1
Other, net	-2	-2
Net cash flows provided (used) by financing activities	210	-56
Effect of foreign exchange rate changes on cash	1	-7
Transfer of cash to assets held for sale	-14	'
Net change in cash	11	-33
Cash, beginning of year	195	156
Cash, end of period	$206	$123

Condensed_Consolidated_Stateme4

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (USD $)	Total	Common stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss) [Member]	Treasury stock [Member]	Notes receivable for the issuance of common stock [Member]
In Millions, unless otherwise specified
Balance at Dec. 31, 2012	'	$683	$2,146	$8,774	$831	($99)	($21)
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net income (loss)	250	'	'	250	'	'	'
Other comprehensive income (loss), net of tax	-104	'	'	'	-104	'	'
Dividends paid to common stockholders	'	'	'	-55	'	'	'
Stock-based compensation	'	'	-8	'	'	7	'
(Increase) Decrease in notes receivable from the issuance of common stock	'	'	'	'	'	'	1
Balance at Mar. 31, 2013	12,405	683	2,138	8,969	727	-92	-20
Balance at Dec. 31, 2013	12,651	683	2,145	9,495	442	-91	-23
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net income (loss)	13	'	'	13	'	'	'
Other comprehensive income (loss), net of tax	250	'	'	'	250	'	'
Dividends paid to common stockholders	'	'	'	-338	'	'	'
Stock-based compensation	'	'	-1	'	'	6	'
(Increase) Decrease 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)

General

General	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
General	'
	Note A. General
	Basis of Presentation
	The Condensed Consolidated Financial Statements (Unaudited) include the accounts of CNA Financial Corporation (CNAF) and its subsidiaries. Collectively, CNAF and its subsidiaries are referred to as CNA or the Company. Loews Corporation (Loews) owned approximately 90% of the outstanding common stock of CNAF as of March 31, 2014.
	The accompanying Condensed Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). Certain financial information that is normally included in annual financial statements, including certain financial statement notes, prepared in accordance with GAAP, is not required for interim reporting purposes and has been condensed or omitted. These statements should be read in conjunction with the Consolidated Financial Statements and notes thereto included in CNAF's Annual Report on Form 10-K filed with the Securities and Exchange Commission for the year ended December 31, 2013, 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, 2014 and for the three months ended March 31, 2014 and 2013 is unaudited. However, in the opinion of management, the interim data includes all adjustments, consisting of normal recurring accruals, necessary for a fair statement of the Company's results for the interim periods. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the full year. Intercompany amounts have been eliminated.
	Sale of Continental Assurance Company (CAC)
	On February 10, 2014, the Company entered into a definitive agreement to sell the majority of its run-off annuity and pension deposit business through the sale of the common stock of CAC. The sale is subject to regulatory approvals and other customary closing conditions and is expected to close in the second quarter of 2014. The business being sold, which was previously reported within the Life & Group Non-Core segment, is now reported as discontinued operations and assets and liabilities held for sale. The Company has elected not to present these assets and liabilities as held for sale on the comparative Condensed Consolidated Balance Sheet. Further information on the assets and liabilities held for sale and discontinued operations is provided in Note M to the Condensed Consolidated Financial Statements.
	The definitive agreement provides for a pre-close dividend by CAC and also includes a 100% coinsurance agreement on a separate small block of annuity business outside of CAC. The assets and liabilities related to the coinsurance agreement and the assets related to the estimated dividend do not qualify as held for sale presentation, therefore they are not reflected as held for sale on the Condensed Consolidated Balance Sheet.

Earnings_Per_Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2014
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 impact of dilutive securities and is computed by dividing Net income (loss) by the weighted average number of common shares outstanding for the period. Diluted earnings (loss) per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock.
	For the three months ended March 31, 2014 and 2013, approximately 660 thousand and 372 thousand potential shares attributable to exercises under stock-based employee compensation plans were included in the calculation of diluted earnings per share. For those same periods, approximately 110 thousand and 335 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, 2014
Investments [Abstract]	'
Investments	'
	Note C. Investments
	The significant components of net investment income are presented in the following table.
	Net Investment Income
	Three months ended March 31
	(In millions)	2014			2013
	Fixed maturity securities	$	452		$	457
	Short term investments	1			1
	Limited partnership investments	73			131
	Equity securities	2			3
	Mortgage loans	6			5
	Trading portfolio	3			5
	Other	2			1
	Gross investment income	539			603
	Investment expense	(13		)	(12		)
	Net investment income	$	526		$	591
	Net realized investment gains (losses) are presented in the following table.
	Net Realized Investment Gains (Losses)
	Three months ended March 31
	(In millions)	2014			2013
	Net realized investment gains (losses):
	Fixed maturity securities:
	Gross realized gains	$	53		$	39
	Gross realized losses	(15		)	(12		)
	Net realized investment gains (losses) on fixed maturity securities	38			27
	Equity securities:
	Gross realized gains	5			2
	Gross realized losses	—			(15		)
	Net realized investment gains (losses) on equity securities	5			(13		)
	Derivatives	—			2
	Short term investments and other	3			7
	Net realized investment gains (losses)	$	46		$	23
	The components of net other-than-temporary impairment (OTTI) losses recognized in earnings by asset type are summarized in the following table.
	Three months ended March 31
	(In millions)	2014			2013
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	1		$	3
	Asset-backed - residential mortgage-backed	1			—
	Total fixed maturity securities available-for-sale	2			3
	Equity securities available-for-sale:
	Preferred stock	—			15
	Net OTTI losses recognized in continuing earnings	$	2		$	18
	The following tables provide a summary of fixed maturity and equity securities.
	Summary of Fixed Maturity and Equity Securities
	March 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	$	17,265		$	1,612		$	56	$	18,821	$	—
	States, municipalities and political subdivisions	11,113			871			129		11,855		—
	Asset-backed:
	Residential mortgage-backed	4,854			156			66		4,944		(47		)
	Commercial mortgage-backed	1,974			92			13		2,053		(3		)
	Other asset-backed	966			12			2		976		—
	Total asset-backed	7,794			260			81		7,973		(50		)
	U.S. Treasury and obligations of government-sponsored enterprises	135			7			1		141		—
	Foreign government	559			18			1		576		—
	Redeemable preferred stock	32			2			—		34		—
	Total fixed maturity securities available-for-sale	36,898			2,770			268		39,400		$	(50	)
	Total fixed maturity securities trading	15			—			—		15
	Equity securities available-for-sale:
	Common stock	33			9			—		42
	Preferred stock	130			2			—		132
	Total equity securities available-for-sale	163			11			—		174
Total	$	37,076		$	2,781		$	268	$	39,589
December 31, 2013	Cost or			Gross			Gross		Estimated		Unrealized
	Amortized			Unrealized			Unrealized		Fair		OTTI
(In millions)	Cost			Gains			Losses		Value		Losses (Gains)
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	19,352		$	1,645		$	135	$	20,862	$	—
States, municipalities and political subdivisions	11,281			548			272		11,557		—
Asset-backed:
Residential mortgage-backed	4,940			123			92		4,971		(37		)
Commercial mortgage-backed	1,995			90			22		2,063		(3		)
Other asset-backed	945			13			3		955		—
Total asset-backed	7,880			226			117		7,989		(40		)
U.S. Treasury and obligations of government-sponsored enterprises	139			6			1		144		—
Foreign government	531			15			3		543		—
Redeemable preferred stock	92			10			—		102		—
Total fixed maturity securities available-for-sale	39,275			2,450			528		41,197		$	(40	)
Total fixed maturity securities trading	36			—			—		36
Equity securities available-for-sale:
Common stock	36			9			—		45
Preferred stock	143			1			4		140
Total equity securities available-for-sale	179			10			4		185
Total	$	39,490		$	2,460		$	532	$	41,418
The net unrealized gains on investments included in the tables above are recorded as a component of Accumulated other comprehensive income (AOCI). When presented in AOCI, these amounts are net of tax and any required Shadow Adjustments. At March 31, 2014 and December 31, 2013, the net unrealized gains on investments included in AOCI were net of after-tax Shadow Adjustments of $712 million and $532 million. To the extent that unrealized gains on fixed income securities supporting certain products within the Life & Group Non-Core segment would result in a premium deficiency if realized, a related decrease in Deferred acquisition costs and/or increase in Insurance reserves are recorded, net of tax, as a reduction of net unrealized gains through Other comprehensive income (loss) (Shadow Adjustments).
The following tables summarize the estimated fair value and gross unrealized losses of available-for-sale fixed maturity and equity securities in a gross unrealized loss position by the length of time in which the securities have continuously been in that position.
Securities in a Gross Unrealized Loss Position
	Less than 12 Months						12 Months or Longer				Total
March 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	$	2,002		$	48		$	109	$	8	$	2,111		$	56
States, municipalities and political subdivisions	1,397			56			244		73		1,641			129
Asset-backed:
Residential mortgage-backed	739			13			347		53		1,086			66
Commercial mortgage-backed	515			12			91		1		606			13
Other asset-backed	167			2			3		—		170			2
Total asset-backed	1,421			27			441		54		1,862			81
U.S. Treasury and obligations of government-sponsored enterprises	6			1			3		—		9			1
Foreign government	61			1			4		—		65			1
Total fixed maturity securities available-for-sale	4,887			133			801		135		5,688			268
Equity securities available-for-sale:
Preferred stock	16			—			—		—		16			—
Total	$	4,903		$	133		$	801	$	135	$	5,704		$	268
	Less than 12 Months						12 Months or Longer				Total
December 31, 2013	Estimated			Gross			Estimated		Gross		Estimated			Gross
	Fair Value			Unrealized			Fair Value		Unrealized		Fair Value			Unrealized
(In millions)				Losses					Losses					Losses
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	3,592		$	129		$	72	$	6	$	3,664		$	135
States, municipalities and political subdivisions	3,251			197			129		75		3,380			272
Asset-backed:
Residential mortgage-backed	1,293			29			343		63		1,636			92
Commercial mortgage-backed	640			22			—		—		640			22
Other asset-backed	269			3			—		—		269			3
Total asset-backed	2,202			54			343		63		2,545			117
U.S. Treasury and obligations of government-sponsored enterprises	13			1			—		—		13			1
Foreign government	111			3			—		—		111			3
Total fixed maturity securities available-for-sale	9,169			384			544		144		9,713			528
Equity securities available-for-sale:
Preferred stock	87			4			—		—		87			4
Total	$	9,256		$	388		$	544	$	144	$	9,800		$	532
Based on current facts and circumstances, the Company believes the unrealized losses presented in the March 31, 2014 Securities in a Gross Unrealized Loss Position table above, are primarily attributable to broader economic conditions, changes in interest rates and credit spreads, market illiquidity and other market factors, but are not indicative of the ultimate collectibility of the current amortized cost of the securities. The investments with longer duration, primarily included within the states, municipalities and political subdivision asset category, were more significantly affected by changes in market interest rates. The Company has no current intent to sell these securities, nor is it more likely than not that it will be required to sell prior to recovery of amortized cost; accordingly, the Company has determined that there are no additional OTTI losses to be recorded at March 31, 2014.
The following table summarizes the activity for the three months ended March 31, 2014 and 2013 related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held at March 31, 2014 and 2013 for which a portion of an OTTI loss was recognized in Other comprehensive income (loss).
Three months ended March 31
(In millions)	2014			2013
Beginning balance of credit losses on fixed maturity securities	$	74		$	95
Reductions for securities sold during the period	(2		)	(3		)
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	$	69		$	92
Contractual Maturity
The following table summarizes available-for-sale fixed maturity securities by contractual maturity at March 31, 2014 and December 31, 2013. Actual maturities may differ from contractual maturities because certain securities may be called or prepaid with or without call or prepayment penalties. Securities not due at a single date are allocated based on weighted average life.
Contractual Maturity
	March 31, 2014						December 31, 2013
(In millions)	Cost or			Estimated			Cost or		Estimated
	Amortized			Fair			Amortized		Fair
	Cost			Value			Cost		Value
Due in one year or less	$	2,684		$	2,729		$	2,420	$	2,455
Due after one year through five years	8,839			9,401			9,496		10,068
Due after five years through ten years	11,455			11,876			11,667		11,954
Due after ten years	13,920			15,394			15,692		16,720
Total	$	36,898		$	39,400		$	39,275	$	41,197
Investment Commitments
As of March 31, 2014, the Company had committed approximately $384 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, 2014, the Company had mortgage loan commitments of $59 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, 2014, the Company had commitments to purchase or fund additional amounts of $154 million and sell $180 million under the terms of such securities.

Derivative_Financial_Instrumen

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2014
Summary of Derivative Instruments [Abstract]	'
Derivative Financial Instruments	'
	Note D. Derivative Financial Instruments
	Gross estimated fair values of derivative positions are presented in Other invested assets and Other liabilities on the Condensed Consolidated Balance Sheets. There would be no significant difference in the balance included in such accounts if the estimated fair values were presented net at March 31, 2014 and December 31, 2013. The contractual or notional amounts for derivatives are used to calculate the exchange of contractual payments under the agreements and may not be representative of the potential for gain or loss on these instruments.
	Derivative Financial Instruments
	March 31, 2014	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Equity warrants	$	5	$	—	$	—
	December 31, 2013	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Equity warrants	$	5	$	—	$	—
	During the three months ended March 31, 2014, new derivative transactions entered into and termination activity each totaled $67 million in notional value. This activity was primarily attributable to interest rate futures. During the three months ended March 31, 2013, new derivative transactions entered into totaled $604 million in notional value while derivative termination activity totaled $542 million. This activity was primarily attributable to forward commitments for mortgage-backed securities, interest rate futures and foreign currency forwards.

Fair_Value

Fair Value	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value	'
	Note E. Fair Value
	Fair value is the price that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The following fair value hierarchy is used in selecting inputs, with the highest priority given to Level 1, as these are the most transparent or reliable.
	Level 1 - Quoted prices for identical instruments in active markets.
	Level 2 - Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs are observable in active markets.
	Level 3 - Valuations derived from valuation techniques in which one or more significant inputs are not observable.
	Prices may fall within Level 1, 2 or 3 depending upon the methodologies and inputs used to estimate fair value for each specific security. 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 and nonrecurring basis are summarized below.
	March 31, 2014											Total
												Assets/(Liabilities)
	(In millions)	Level 1				Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	24			$	18,623		$	189		$	18,836
	States, municipalities and political subdivisions	—				11,769			86			11,855
	Asset-backed:
	Residential mortgage-backed	—				4,585			359			4,944
	Commercial mortgage-backed	—				1,927			126			2,053
	Other asset-backed	—				537			439			976
	Total asset-backed	—				7,049			924			7,973
	U.S. Treasury and obligations of government-sponsored enterprises	135				6			—			141
	Foreign government	76				500			—			576
	Redeemable preferred stock	23				11			—			34
	Total fixed maturity securities	258				37,958			1,199			39,415
	Equity securities	117				55			2			174
	Other invested assets	—				55			—			55
	Short term investments	1,353				651			—			2,004
	Life settlement contracts, included in Other assets	—				—			87			87
	Total recurring basis assets	1,728				38,719			1,288			41,735
	Assets held for sale - nonrecurring basis	—		—		3,486			—			3,486
	Total assets	$	1,728			$	42,205		$	1,288		$	45,221
	Liabilities
	Liabilities held for sale - nonrecurring basis	$	—			$	3,250		$	—		$	3,250
	Total liabilities	$	—			$	3,250		$	—		$	3,250
	December 31, 2013										Total
											Assets/(Liabilities)
	(In millions)	Level 1			Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	33		$	20,661		$	204		$	20,898
	States, municipalities and political subdivisions	—			11,486			71			11,557
	Asset-backed:
	Residential mortgage-backed	—			4,640			331			4,971
	Commercial mortgage-backed	—			1,912			151			2,063
	Other asset-backed	—			509			446			955
	Total asset-backed	—			7,061			928			7,989
	U.S. Treasury and obligations of government-sponsored enterprises	116			28			—			144
	Foreign government	81			462			—			543
	Redeemable preferred stock	45			57			—			102
	Total fixed maturity securities	275			39,755			1,203			41,233
	Equity securities	126			48			11			185
	Other invested assets	—			54			—			54
	Short term investments	769			563			—			1,332
	Life settlement contracts, included in Other assets	—			—			88			88
	Separate account business	9			171			1			181
	Total assets	$	1,179		$	40,591		$	1,303		$	43,073
	The tables below present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended March 31, 2014 and 2013.
	Level 3	Balance at			Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at			Unrealized gains (losses) on Level 3 assets and liabilities held at March 31, 2014 recognized in net income (loss)*
	(In millions)	January 1,																		Level 3		of Level 3			March 31,
		2014																							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
Level 3	Balance at			Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at			Unrealized gains (losses) on Level 3 assets and liabilities held at March 31, 2013 recognized in net income (loss)*
(In millions)	January 1,																		Level 3		of Level 3			March 31,
	2013																							2013
Fixed maturity securities:
Corporate and other bonds	$	219		$	—		$	2		$	110		$	(17	)	$	(20	)	$	26	$	(18	)	$	302		$	(1	)
States, municipalities and political subdivisions	96			(3		)	—			85			(47		)	(2		)	—		—			129			—
Asset-backed:
Residential mortgage-backed	413			3			—			61			—			(11		)	—		(16		)	450			—
Commercial mortgage-backed	129			1			5			73			—			(7		)	—		(24		)	177			—
Other asset-backed	368			3			1			136			(99		)	(13		)	—		—			396			—
Total asset-backed	910			7			6			270			(99		)	(31		)	—		(40		)	1,023			—
Redeemable preferred stock	26			—			—			—			—			—			—		—			26			—
Total fixed maturity securities	1,251			4			8			465			(163		)	(53		)	26		(58		)	1,480			(1		)
Equity securities	34			(15		)	1			—			—			—			—		(1		)	19			(15		)
Other invested assets, including derivatives, net	—			—			—			—			(1		)	—			—		—			(1		)	—
Short term investments	6			—			—			—			(1		)	—			—		—			5			—
Life settlement contracts	100			7			—			—			—			(12		)	—		—			95			—
Separate account business	2			—			—			—			—			—			—		—			2			—
Total	$	1,393		$	(4	)	$	9		$	465		$	(165	)	$	(65	)	$	26	$	(59	)	$	1,600		$	(16	)
* Net realized and unrealized gains and losses shown above are reported in Net income (loss) as follows:
Major Category of Assets and Liabilities		Condensed Consolidated Statements of Operations Line Items
Fixed maturity securities available-for-sale		Net realized investment gains (losses)
Fixed maturity securities trading		Net investment income
Equity securities		Net realized investment gains (losses)
Other invested assets - Derivative financial instruments held in a trading portfolio		Net investment income
Other invested assets - Derivative financial instruments not held in a trading portfolio		Net realized investment gains (losses)
Other invested assets - Overseas deposits		Net investment income
Life settlement contracts		Other revenues
Securities shown in the Level 3 tables on the previous pages may be transferred in or out of Level 3 based on the availability of observable market information used to determine the fair value of the security. The availability of observable market information varies based on market conditions and trading volume and may cause securities to move in and out of Level 3 from reporting period to reporting period. There were $23 million of transfers from Level 2 to Level 1 and $1 million of transfers from Level 1 to Level 2 during the three months ended March 31, 2014. There were no transfers between Level 1 and Level 2 during the three months ended March 31, 2013. The Company's policy is to recognize transfers between levels at the beginning of quarterly reporting periods.
Valuation Methodologies and Inputs
The following section describes the valuation methodologies and relevant inputs used to measure different financial instruments at fair value, including an indication of the level in the fair value hierarchy in which the instruments are generally classified.
Fixed Maturity Securities
Fixed maturity securities are valued using methodologies that model information generated by market transactions involving identical or comparable assets, as well as discounted cash flow methodologies. Common inputs include: prices from recently executed transactions of similar securities, broker/dealer quotes, benchmark yields, spreads off benchmark yields, interest rates, and U.S. Treasury or swap curves. Specifically for asset-backed securities, key inputs include prepayment and default projections based on past performance of the underlying collateral and current market data.
Level 1 securities include exchange traded bonds, highly liquid U.S. and foreign government bonds, and redeemable preferred stock, valued using quoted market prices. Level 2 securities include most other fixed maturity securities as the significant inputs are observable in the marketplace. Securities are generally assigned to Level 3 in cases where broker/dealer quotes are significant inputs to the valuation and there is a lack of transparency as to whether these quotes are based on information that is observable in the marketplace. Level 3 securities also include 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.
Other Invested Assets
Level 1 securities include exchange traded derivatives, primarily futures, valued using quoted market prices. Level 2 securities include overseas deposits, which can be redeemed at net asset value in 90 days or less, and derivatives, primarily currency forwards valued using observable market forward rates. Over-the-counter derivatives, principally interest rate swaps, total return swaps, credit default swaps, equity warrants and options, are valued using inputs including broker/dealer quotes and are classified within Level 3 of the valuation hierarchy due to a lack of transparency as to whether these quotes are based on information that is observable in the marketplace.
Short Term Investments
Securities that are actively traded or have quoted prices are classified as Level 1. These securities include money market funds and treasury bills. Level 2 primarily includes commercial paper, for which all inputs are market observable. Fixed maturity securities purchased within one year of maturity are classified consistent with fixed maturity securities discussed above. Short term investments as presented in the tables above differ from the amounts presented on the Condensed Consolidated Balance Sheets because certain short term investments, such as time deposits, are not measured at fair value.
Life Settlement Contracts
The fair values of life settlement contracts are determined as the present value of the anticipated death benefits less anticipated premium payments based on contract terms that are distinct for each insured, as well as the Company's own assumptions for mortality, premium expense, and the rate of return that a buyer would require on the contracts, as no comparable market pricing data is available.
Separate Account Business
Separate account business includes fixed maturity securities, equities and short term investments. The valuation methodologies and inputs for these asset types have been described above.
Assets and Liabilities Held for Sale on a Nonrecurring Basis
Assets and liabilities held for sale include assets and liabilities of CAC. These assets and liabilities are valued using the agreed upon transaction price for the sale of the common stock of CAC and are classified within Level 2 of the fair value hierarchy. See Notes A and M to the Condensed Consolidated Financial Statements for further discussion of the assets and liabilities classified as held for sale.
Significant Unobservable Inputs
The table below presents quantitative information about the significant unobservable inputs utilized by the Company in the fair value measurements of Level 3 assets. Valuations for assets and liabilities not presented in the table below are primarily based on broker/dealer quotes for which there is a lack of transparency as to inputs used to develop the valuations. The quantitative detail of these unobservable inputs is neither provided nor reasonably available to the Company.
Assets	Fair Value at March 31, 2014			Valuation Technique		Unobservable Input(s)	Range
(In millions)							(Weighted Average)
Fixed maturity securities	$	116		Discounted cash flow		Credit spread	2% - 15% (4%)
Equity securities	$	2		Market approach		Private offering price	$4,295 per share
Life settlement contracts	$	87		Discounted cash flow		Discount rate risk premium	9%
						Mortality assumption	70% - 743% (191%)
Assets	Fair Value at December 31, 2013			Valuation Technique		Unobservable Input(s)	Range
(In millions)							(Weighted Average)
Fixed maturity securities	$	142		Discounted cash flow		Credit spread	2% - 20% (4%)
Equity securities	$	10		Market approach		Private offering price	$360 - $4,268 per share ($1,148)
Life settlement contracts	$	88		Discounted cash flow		Discount rate risk premium	9%
						Mortality assumption	70% - 743% (192%)
For fixed maturity securities, an increase in the credit spread assumptions would result in a lower fair value measurement. For equity securities, an increase in the private offering price, earnings projections and earnings multiple would result in a higher fair value measurement. For life settlement contracts, an increase in the discount rate risk premium or decrease in the mortality assumption would result in a lower fair value measurement.
Financial Assets and Liabilities Not Measured at Fair Value
The carrying amount and estimated fair value of the Company's financial instrument assets and liabilities which are not measured at fair value on the Condensed Consolidated Balance Sheets are listed in the tables below.
March 31, 2014	Carrying			Estimated Fair Value
(In millions)	Amount			Level 1			Level 2			Level 3			Total
Financial assets
Notes receivable for the issuance of common stock	$	22		$	—		$	—		$	22		$	22
Mortgage loans	495			—			—			510			510
Financial liabilities
Short term debt	$	549		—			569			—			569
Long term debt	2,558			—			2,908			—			2,908
December 31, 2013	Carrying			Estimated Fair Value
(In millions)	Amount			Level 1			Level 2			Level 3			Total
Financial assets
Notes receivable for the issuance of common stock	$	23		$	—		$	—		$	23		$	23
Mortgage loans	508			—			—			515			515
Financial liabilities
Premium deposits and annuity contracts	$	57		$	—		$	—		$	58		$	58
Short term debt	549			—			575			—			575
Long term debt	2,011			—			2,328			—			2,328
The following methods and assumptions were used to estimate the fair value of these financial assets and liabilities.
The fair values of Notes receivable for the issuance of common stock were estimated using discounted cash flows utilizing interest rates currently offered for obligations securitized with similar collateral, adjusted for specific note receivable risk.
The fair values of Mortgage loans were based on the present value of the expected future cash flows discounted at the current interest rate for origination of similar quality loans, adjusted for specific loan risk.
Premium deposits and annuity contracts were valued based on cash surrender values or estimated fair values of policyholder liabilities, net of amounts ceded related to sold business.
The Company's senior notes and debentures were valued based on observable market prices. The fair value for other debt was estimated using discounted cash flows based on current incremental borrowing rates for similar borrowing arrangements.
The carrying amounts reported on the Condensed Consolidated Balance Sheets for Cash, Short term investments not carried at fair value, Accrued investment income and certain other assets and other liabilities approximate fair value due to the short term nature of these items. These assets and liabilities are not listed in the tables above.

Claim_and_Claim_Adjustment_Exp

Claim and Claim Adjustment Expense Reserves	3 Months Ended
	Mar. 31, 2014
Insurance Loss Reserves [Abstract]	'
Claim and Claim Adjustment Expense Reserves	'
	Note F. Claim and Claim Adjustment Expense Reserves
	The Company's property and casualty insurance claim and claim adjustment expense reserves represent the estimated amounts necessary to resolve all outstanding claims, including IBNR claims as of the reporting date. The Company's reserve projections are based primarily on detailed analysis of the facts in each case, the Company's experience with similar cases and various historical development patterns. Consideration is given to such historical patterns as field reserving trends and claims settlement practices, loss payments, pending levels of unpaid claims and product mix, as well as court decisions, economic conditions including inflation, and public attitudes. All of these factors can affect the estimation of claim and claim adjustment expense reserves.
	Establishing claim and claim adjustment expense reserves, including claim and claim adjustment expense reserves for catastrophic events that have occurred, is an estimation process. Many factors can ultimately affect the final settlement of a claim and, therefore, the necessary reserve. Changes in the law, results of litigation, medical costs, the cost of repair materials and labor rates can all affect ultimate claim costs. In addition, time can be a critical part of reserving determinations since the longer the span between the incidence of a loss and the payment or settlement of the claim, the more variable the ultimate settlement amount can be. Accordingly, short-tail claims, such as property damage claims, tend to be more reasonably estimable than long-tail claims, such as workers' compensation, general liability and professional liability claims. Adjustments to prior year reserve estimates, if necessary, are reflected in the results of operations in the period that the need for such adjustments is determined. There can be no assurance that the Company's ultimate cost for insurance losses will not exceed current estimates.
	Catastrophes are an inherent risk of the property and casualty insurance business and have contributed to material period-to-period fluctuations in the Company's results of operations and/or equity. The Company reported catastrophe losses, net of reinsurance, of $74 million and $39 million for the three months ended March 31, 2014 and 2013. Catastrophe losses in the first quarter of 2014 related primarily to U.S. winter weather-related events.
	Net Prior Year Development
	The following tables and discussion include the net prior year development recorded for CNA Specialty, CNA Commercial, Hardy and Corporate & Other Non-Core segments.
	Net Prior Year Development
	Three months ended March 31, 2014
	(In millions)	CNA			CNA Commercial			Hardy			Corporate		Total
		Specialty									& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(2	)	$	17		$	10		$	—	$	25
	Pretax (favorable) unfavorable premium development	(8		)	(19		)	(4		)	—		(31		)
	Total pretax (favorable) unfavorable net prior year development	$	(10	)	$	(2	)	$	6		$	—	$	(6	)
	Three months ended March 31, 2013
	(In millions)	CNA			CNA Commercial			Hardy			Corporate		Total
		Specialty									& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(15	)	$	(11	)	$	(1	)	$	1	$	(26	)
	Pretax (favorable) unfavorable premium development	(8		)	(10		)	4			1		(13		)
	Total pretax (favorable) unfavorable net prior year development	$	(23	)	$	(21	)	$	3		$	2	$	(39	)
	CNA Specialty
	The following table provides further detail of the net prior year claim and allocated claim adjustment expense reserve development (development) recorded for the CNA Specialty segment for the three months ended March 31, 2014 and 2013.
	Three months ended March 31
	(In millions)	2014			2013
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Medical Professional Liability	$	1		$	(3	)
	Other Professional Liability and Management Liability	(6		)	(1		)
	Surety	1			1
	Warranty	—			—
	Other	2			(12		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(2	)	$	(15	)
	2014
	Favorable development for other professional liability and management liability was related to better than expected loss emergence in accident years 2004 and prior.
	2013
	Overall, favorable development for medical professional liability reflects favorable experience in accident years 2009 and prior. Unfavorable development was recorded for accident years 2010 and 2011 due to higher than expected large loss activity.
	Other includes standard property and casualty coverages provided to CNA Specialty customers. Favorable development for other coverages was primarily due to better than expected loss emergence in property coverages in accident years 2010 and subsequent.
	.
	CNA Commercial
	The following table provides further detail of the development recorded for the CNA Commercial segment for the three months ended March 31, 2014 and 2013.
	Three months ended March 31
	(In millions)	2014			2013
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Commercial Auto	$	20		$	(5	)
	General Liability	(5		)	(21		)
	Workers' Compensation	10			25
	Property and Other	(8		)	(10		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	17		$	(11	)
	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.
	2013
	Favorable development in the general liability coverages was primarily due to better than expected loss emergence in accident years 2002 and prior.
	Unfavorable development for workers' compensation was primarily due to higher than expected large losses and increased severity in the state of California in accident year 2010.
	Hardy
	The following table provides further detail of the development recorded for the Hardy segment for the three months ended March 31, 2014 and 2013.
	Three months ended March 31
	(In millions)	2014			2013
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Marine and Aviation	$	5		$	(1	)
	Non-Marine Property	(2		)	—
	Property Treaty	(2		)	—
	Specialty	(1		)	—
Commutations	10			—
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	10		$	(1	)
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, 2014
Legal Proceedings and Contingent Liabilities [Abstract]	'
Legal Proceedings and Contingent Liabilities	'
	Note G. Legal Proceedings and Contingent Liabilities
	The Company is a party to routine litigation incidental to its business, which, based on the facts and circumstances currently known, is not material to the Condensed Consolidated Financial Statements.

Benefit_Plans

Benefit Plans	3 Months Ended
	Mar. 31, 2014
Compensation and Retirement Disclosure [Abstract]	'
Benefit Plans	'
	Note H. Benefit Plans
	The components of net periodic cost (benefit) are presented in the following table.
	Net Periodic Cost (Benefit)
	Three months ended March 31
	(In millions)	2014			2013
	Pension cost (benefit)
	Service cost	$	3		$	3
	Interest cost on projected benefit obligation	33			30
	Expected return on plan assets	(48		)	(45		)
	Amortization of net actuarial (gain) loss	6			12
	Net periodic pension cost (benefit)	$	(6	)	$	—
	Postretirement cost (benefit)
	Amortization of prior service credit	$	(4	)	$	(4	)
	Net periodic postretirement cost (benefit)	$	(4	)	$	(4	)

Other_Intangible_Assets

Other Intangible Assets	3 Months Ended
	Mar. 31, 2014
Intangible Assets, Gross (Excluding Goodwill) [Abstract]	'
Other Intangible Assets	'
	Note I. Other Intangible Assets
	Other intangible assets are presented in the following table.
			31-Mar-14				31-Dec-13
	(In millions)	Economic Useful Life	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
	Finite-lived intangible assets:
	Value of business acquired	1 - 4 years	$	64	$	64	$	64	$	63
	Trade name	8 years	9		2		8		2
	Distribution channel	15 years	13		1		13		1
	Total finite-lived intangible assets		86		67		85		66
	Indefinite-lived intangible assets:
	Syndicate capacity		58				58
	Agency force		16				16
	Total indefinite-lived intangible assets		74				74
	Total other intangible assets		$	160	$	67	$	159	$	66
	For the three months ended March 31, 2014 and 2013, amortization expense of $1 million and $9 million was included in Amortization of deferred acquisition costs and for the three months ended March 31, 2013, $3 million was recorded in Other operating expenses in the Statement of Operations for the Hardy segment. The gross carrying amounts and accumulated amortization in the table above may change from period to period as a result of foreign currency translation. Estimated future amortization expense for intangible assets is $1 million in 2015 and $2 million in years 2016, 2017 and 2018.

Commitments_Contingencies_and_

Commitments, Contingencies, and Guarantees	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments, Contingencies, and Guarantees	'
	Note J. Commitments, Contingencies, and Guarantees
	Commitments and Contingencies
	The Company holds an investment in a real estate joint venture. In the normal course of business, the Company, on a joint and several basis with other unrelated insurance company shareholders, has committed to continue funding the operating deficits of this joint venture. Additionally, the Company and the other unrelated shareholders, on a joint and several basis, have guaranteed an operating lease for an office building, which expires in 2016. The guarantee of the operating lease is a parallel guarantee to the commitment to fund operating deficits; consequently, the separate guarantee to the lessor is not expected to be triggered as long as the joint venture continues to be funded by its shareholders which provide liquidity to make its annual lease payments.
	In the event that the other parties to the joint venture are unable to meet their commitments in funding the operations of this joint venture, the Company would be required to assume the obligation for the entire office building operating lease. The Company does not believe it is likely that it will be required to do so.  However, the maximum potential future lease payments and other related costs at March 31, 2014 that the Company could be required to pay under this guarantee, in excess of amounts already recorded, were approximately $77 million. If the Company were required to assume the entire lease obligation, the Company would have the right to pursue reimbursement from the other shareholders and the right to all sublease revenues.
	Guarantees
	In the course of selling business entities and assets to third parties, the Company has agreed to indemnify purchasers for losses arising out of breaches of representation and warranties with respect to the business entities or assets being sold, including, in certain cases, losses arising from undisclosed liabilities or certain named litigation. Such indemnification agreements may include provisions that survive indefinitely. As of March 31, 2014, the aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third-party loans was $702 million.
	In addition, the Company has agreed to provide indemnification to third-party purchasers for certain losses associated with sold business entities or assets that are not limited by a contractual monetary amount. As of March 31, 2014, the Company had outstanding unlimited indemnifications in connection with the sales of certain of its business entities or assets that included tax liabilities arising prior to a purchaser's ownership of an entity or asset, defects in title at the time of sale, employee claims arising prior to closing and in some cases losses arising from certain litigation and undisclosed liabilities. These indemnification agreements survive until the applicable statutes of limitation expire or until the agreed upon contract terms expire.
	As of March 31, 2014 and December 31, 2013, the Company had recorded liabilities of approximately $7 million related to indemnification agreements and management believes that it is not likely that any future indemnity claims will be significantly greater than the amounts recorded.

Business_Segments

Business Segments	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Business Segments	'
	Note K. Business Segments
	The Company's core property and casualty commercial insurance operations are reported in three business segments: CNA Specialty, CNA Commercial and Hardy. The Company's non-core operations are managed in two segments: Life & Group Non-Core and Corporate & Other Non-Core.
	The accounting policies of the segments are the same as those described in Note A of the Consolidated Financial Statements within CNAF's Annual Report on Form 10-K for the year ended December 31, 2013. The Company manages most of its assets on a legal entity basis, while segment operations are generally conducted across legal entities. As such, only insurance and reinsurance receivables, insurance reserves, deferred acquisition costs and goodwill are readily identifiable for all individual segments. Distinct investment portfolios are not maintained for every individual segment; accordingly, allocation of assets to each segment is not performed. Therefore, a significant portion of net investment income and realized investment gains or losses are allocated primarily based on each segment's net carried insurance reserves, as adjusted. All significant intersegment income and expense has been eliminated. Income taxes have been allocated on the basis of the taxable income of the segments.
	In the following tables, certain financial measures are presented to provide information used by management to monitor the Company's operating performance. Management utilizes these financial measures to monitor the Company's insurance operations and investment portfolio. Net operating income, which is derived from certain income statement amounts, is used by management to monitor performance of the Company's insurance operations. The Company's investment portfolio is monitored by management through analysis of various factors including unrealized gains and losses on securities, portfolio duration and exposure to market and credit risk. Based on such analyses, the Company may recognize an OTTI loss on an investment security in accordance with its policy, or sell a security, which may produce realized gains and losses.
	Net operating income (loss) is calculated by excluding from net income (loss) the after-tax effects of 1) net realized investment gains or losses, 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 or losses because net realized investment gains or losses are largely discretionary, except for some losses related to OTTI, and are generally driven by economic factors that are not necessarily consistent with key drivers of underwriting performance, and are therefore not considered an indication of trends in insurance operations.
	The results of the Company's continuing operations and selected balance sheet items are presented in the following tables.
	Three months ended March 31, 2014	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	748		$	822		$	98		$	139		$	—		$	(1	)	$	1,806
	Net investment income	151			198			1			171			5			—			526
	Other revenues	68			9			1			5			2			—			85
	Total operating revenues	967			1,029			100			315			7			(1		)	2,417
	Claims, Benefits and Expenses
	Net incurred claims and benefits	480			622			38			306			(3		)	—			1,443
	Policyholders’ dividends	1			2			—			—			—			—			3
	Amortization of deferred acquisition costs	153			140			28			8			—			—			329
	Other insurance related expenses	72			139			20			32			—			(1		)	262
	Other expenses	61			11			4			1			51			—			128
	Total claims, benefits and expenses	767			914			90			347			48			(1		)	2,165
	Operating income (loss) before income tax	200			115			10			(32		)	(41		)	—			252
	Income tax (expense) benefit on operating income (loss)	(66		)	(37		)	(3		)	30			14			—			(62		)
	Net operating income (loss)	134			78			7			(2		)	(27		)	—			190
	Net realized investment gains (losses), pretax	12			12			—			16			6			—			46
	Income tax (expense) benefit on net realized investment gains (losses)	(4		)	(4		)	—			(6		)	(2		)	—			(16		)
	Net realized investment gains (losses)	8			8			—			10			4			—			30
	Net income (loss) from continuing operations	$	142		$	86		$	7		$	8		$	(23	)	$	—		$	220
	March 31, 2014
	(In millions)
	Reinsurance receivables	$	555		$	1,050		$	153		$	401		$	2,940		$	—		$	5,099
	Insurance receivables	$	794		$	1,134		$	191		$	10		$	3		$	—		$	2,132
	Deferred acquisition costs	$	326		$	273		$	53		$	—		$	—		$	—		$	652
	Goodwill	$	117		$	—		$	38		$	—		$	—		$	—		$	155
	Insurance reserves
	Claim and claim adjustment expenses	$	6,786		$	10,574		$	377		$	3,085		$	3,111		$	—		$	23,933
	Unearned premiums	1,863			1,583			250			142			—			—			3,838
	Future policy benefits	—			—			—			8,254			—			—			8,254
	Policyholders’ funds	9			17			—			—			—			—			26
	Three months ended March 31, 2013	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	723		$	837		$	64		$	141		$	—		$	(1	)	$	1,764
	Net investment income	170			250			1			162			8			—			591
	Other revenues	60			10			1			3			3			—			77
	Total operating revenues	953			1,097			66			306			11			(1		)	2,432
	Claims, Benefits and Expenses
	Net incurred claims and benefits	465			600			31			293			4			—			1,393
	Policyholders’ dividends	1			2			—			—			—			—			3
	Amortization of deferred acquisition costs	150			149			21			8			—			—			328
	Other insurance related expenses	71			143			16			32			—			(1		)	261
	Other expenses	54			9			7			5			46			—			121
	Total claims, benefits and expenses	741			903			75			338			50			(1		)	2,106
	Operating income (loss) before income tax	212			194			(9		)	(32		)	(39		)	—			326
	Income tax (expense) benefit on operating income (loss)	(72		)	(69		)	1			26			13			—			(101		)
	Net operating income (loss)	140			125			(8		)	(6		)	(26		)	—			225
	Net realized investment gains (losses), pretax	3			4			1			9			6			—			23
	Income tax (expense) benefit on net realized investment gains (losses)	(1		)	(1		)	—			(3		)	(2		)	—			(7		)
	Net realized investment gains (losses)	2			3			1			6			4			—			16
	Net income (loss) from continuing operations	$	142		$	128		$	(7	)	$	—		$	(22	)	$	—		$	241
	December 31, 2013
	(In millions)
Reinsurance receivables	$	546		$	1,075		$	197		$	1,203		$	3,067		$	—		$	6,088
Insurance receivables	$	775		$	1,099		$	176		$	11		$	2		$	—		$	2,063
Deferred acquisition costs	$	318		$	257		$	49		$	—		$	—		$	—		$	624
Goodwill	$	117		$	—		$	38		$	—		$	—		$	—		$	155
Insurance reserves
Claim and claim adjustment expenses	$	6,689		$	10,649		$	386		$	3,058		$	3,307		$	—		$	24,089
Unearned premiums	1,805			1,536			249			128			—			—			3,718
Future policy benefits	—			—			—			10,471			—			—			10,471
Policyholders’ funds	9			15			—			92			—			—			116
The following table provides revenue by line of business for each reportable segment. Revenues are comprised of operating revenues and net realized investment gains and losses.
Revenues by Line of Business
Three months ended March 31
(In millions)	2014			2013
CNA Specialty
International	$	64		$	59
Management & Professional Liability	704			700
Surety	122			116
Warranty & Alternative Risks	89			81
CNA Specialty revenues	979			956
CNA Commercial
Commercial Insurance	762			826
International	95			93
Small Business	184			182
CNA Commercial revenues	1,041			1,101
Hardy revenues	100			67
Life & Group Non-Core revenues	331			315
Corporate & Other Non-Core revenues	13			17
Eliminations	(1		)	(1		)
Total revenues	$	2,463		$	2,455

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss) by Component	3 Months Ended
	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Accumulated Other Comprehensive Income (Loss) by Component	'
	Note L. Accumulated Other Comprehensive Income (Loss) by Component
	The tables below display the changes in Accumulated other comprehensive income (loss) by component for the three months ended March 31, 2014 and 2013.
	(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 at 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 at March 31, 2014	$	33		$	912		$	30		$	(425	)	$	142		$	692
	(In millions)	Net unrealized gains (losses) on investments with OTTI losses			Net unrealized gains (losses) on other investments			Pension and postretirement benefits			Cumulative foreign currency translation adjustment			Total
	Balance at January 1, 2013	$	20		$	1,371		$	(721	)	$	161		$	831
	Other comprehensive income (loss) before reclassifications	14			(49		)	—			(61		)	(96		)
	Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(6), $3, $0, and $(3)	—			13			(5		)	—			8
	Other comprehensive income (loss) after tax (expense) benefit of $(7), $35, $(3), $0, and $25	14			(62		)	5			(61		)	(104		)
	Balance at March 31, 2013	$	34		$	1,309		$	(716	)	$	100		$	727
	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

Assets_Liabilities_Held_for_Sa

Assets & Liabilities Held for Sale and Discontinued Operations	3 Months Ended
	Mar. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Assets and Liabilities Held for Sale and Discontinued Operations	'
	Note M. Assets and Liabilities Held for Sale and Discontinued Operations
	The results of discontinued operations reflected in the Condensed Consolidated Statements of Operations were as follows:
	Three months ended March 31
	(In millions)	2014			2013
	Revenues
	Net investment income	$	41		$	42
	Net realized investment gains	1			5
	Other revenues	—			1
	Total revenues	42			48
	Claims, Benefits and Expenses
	Insurance claims and policyholders' benefits	31			33
	Other operating expenses	1			1
	Total claims, benefits and expenses	32			34
	Income before income tax	10			14
	Income tax expense	(3		)	(5		)
	Income from operations of discontinued operations, net of income tax	7			9
	Impairment loss on sale, net of income tax benefit of $41 and -	(214		)	—
	(Loss) income from discontinued operations	$	(207	)	$	9
	The following table presents the detailed assets and liabilities held for sale as of March 31, 2014:
	(In millions)	2014
	Assets
	Investments:
	Fixed maturity securities at fair value	$	2,684
	Equity securities at fair value	16
	Other invested assets	1
	Short term investments	36
	Total investments	2,737
	Cash	14
	Reinsurance receivables	787
	Other assets	55
	Separate account business	148
	Assets held for sale	3,741
	Less: Impairment on sale	(255		)
	Total assets held for sale	$	3,486
	Liabilities
	Insurance reserves	$	3,017
	Other liabilities	85
	Separate account business	148
	Total liabilities held for sale	$	3,250

Investments_Tables

Investments (Tables)	3 Months Ended
	Mar. 31, 2014
Investments [Abstract]	'
Net investment income	'
	Net Investment Income
	Three months ended March 31
	(In millions)	2014			2013
	Fixed maturity securities	$	452		$	457
	Short term investments	1			1
	Limited partnership investments	73			131
	Equity securities	2			3
	Mortgage loans	6			5
	Trading portfolio	3			5
	Other	2			1
	Gross investment income	539			603
	Investment expense	(13		)	(12		)
	Net investment income	$	526		$	591
Net realized investment gains (losses)	'
	Net Realized Investment Gains (Losses)
	Three months ended March 31
	(In millions)	2014			2013
	Net realized investment gains (losses):
	Fixed maturity securities:
	Gross realized gains	$	53		$	39
	Gross realized losses	(15		)	(12		)
	Net realized investment gains (losses) on fixed maturity securities	38			27
	Equity securities:
	Gross realized gains	5			2
	Gross realized losses	—			(15		)
	Net realized investment gains (losses) on equity securities	5			(13		)
	Derivatives	—			2
	Short term investments and other	3			7
	Net realized investment gains (losses)	$	46		$	23
Components of net other-than-temporary impairment losses recognized in continuing earnings	'
	The components of net other-than-temporary impairment (OTTI) losses recognized in earnings by asset type are summarized in the following table.
	Three months ended March 31
	(In millions)	2014			2013
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	1		$	3
	Asset-backed - residential mortgage-backed	1			—
	Total fixed maturity securities available-for-sale	2			3
	Equity securities available-for-sale:
	Preferred stock	—			15
	Net OTTI losses recognized in continuing earnings	$	2		$	18
Summary of fixed maturity and equity securities	'
	Summary of Fixed Maturity and Equity Securities
	March 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	$	17,265		$	1,612		$	56	$	18,821	$	—
	States, municipalities and political subdivisions	11,113			871			129		11,855		—
	Asset-backed:
	Residential mortgage-backed	4,854			156			66		4,944		(47		)
	Commercial mortgage-backed	1,974			92			13		2,053		(3		)
	Other asset-backed	966			12			2		976		—
	Total asset-backed	7,794			260			81		7,973		(50		)
	U.S. Treasury and obligations of government-sponsored enterprises	135			7			1		141		—
	Foreign government	559			18			1		576		—
	Redeemable preferred stock	32			2			—		34		—
	Total fixed maturity securities available-for-sale	36,898			2,770			268		39,400		$	(50	)
	Total fixed maturity securities trading	15			—			—		15
	Equity securities available-for-sale:
	Common stock	33			9			—		42
	Preferred stock	130			2			—		132
	Total equity securities available-for-sale	163			11			—		174
	Total	$	37,076		$	2,781		$	268	$	39,589
	December 31, 2013	Cost or			Gross			Gross		Estimated		Unrealized
		Amortized			Unrealized			Unrealized		Fair		OTTI
	(In millions)	Cost			Gains			Losses		Value		Losses (Gains)
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	19,352		$	1,645		$	135	$	20,862	$	—
	States, municipalities and political subdivisions	11,281			548			272		11,557		—
	Asset-backed:
	Residential mortgage-backed	4,940			123			92		4,971		(37		)
	Commercial mortgage-backed	1,995			90			22		2,063		(3		)
	Other asset-backed	945			13			3		955		—
	Total asset-backed	7,880			226			117		7,989		(40		)
	U.S. Treasury and obligations of government-sponsored enterprises	139			6			1		144		—
	Foreign government	531			15			3		543		—
	Redeemable preferred stock	92			10			—		102		—
	Total fixed maturity securities available-for-sale	39,275			2,450			528		41,197		$	(40	)
	Total fixed maturity securities trading	36			—			—		36
	Equity securities available-for-sale:
	Common stock	36			9			—		45
	Preferred stock	143			1			4		140
	Total equity securities available-for-sale	179			10			4		185
	Total	$	39,490		$	2,460		$	532	$	41,418
Securities in a gross unrealized loss position	'
	Securities in a Gross Unrealized Loss Position
		Less than 12 Months						12 Months or Longer				Total
	March 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	$	2,002		$	48		$	109	$	8	$	2,111		$	56
	States, municipalities and political subdivisions	1,397			56			244		73		1,641			129
	Asset-backed:
	Residential mortgage-backed	739			13			347		53		1,086			66
	Commercial mortgage-backed	515			12			91		1		606			13
	Other asset-backed	167			2			3		—		170			2
	Total asset-backed	1,421			27			441		54		1,862			81
	U.S. Treasury and obligations of government-sponsored enterprises	6			1			3		—		9			1
	Foreign government	61			1			4		—		65			1
	Total fixed maturity securities available-for-sale	4,887			133			801		135		5,688			268
	Equity securities available-for-sale:
	Preferred stock	16			—			—		—		16			—
	Total	$	4,903		$	133		$	801	$	135	$	5,704		$	268
		Less than 12 Months						12 Months or Longer				Total
	December 31, 2013	Estimated			Gross			Estimated		Gross		Estimated			Gross
		Fair Value			Unrealized			Fair Value		Unrealized		Fair Value			Unrealized
	(In millions)				Losses					Losses					Losses
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	3,592		$	129		$	72	$	6	$	3,664		$	135
	States, municipalities and political subdivisions	3,251			197			129		75		3,380			272
	Asset-backed:
	Residential mortgage-backed	1,293			29			343		63		1,636			92
	Commercial mortgage-backed	640			22			—		—		640			22
	Other asset-backed	269			3			—		—		269			3
	Total asset-backed	2,202			54			343		63		2,545			117
	U.S. Treasury and obligations of government-sponsored enterprises	13			1			—		—		13			1
	Foreign government	111			3			—		—		111			3
	Total fixed maturity securities available-for-sale	9,169			384			544		144		9,713			528
	Equity securities available-for-sale:
	Preferred stock	87			4			—		—		87			4
	Total	$	9,256		$	388		$	544	$	144	$	9,800		$	532
Activity related to the pretax fixed maturity credit loss component reflected within retained earnings for securities still held for which a portion of an OTTI loss was recognized in OCI	'
	The following table summarizes the activity for the three months ended March 31, 2014 and 2013 related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held at March 31, 2014 and 2013 for which a portion of an OTTI loss was recognized in Other comprehensive income (loss).
	Three months ended March 31
	(In millions)	2014			2013
	Beginning balance of credit losses on fixed maturity securities	$	74		$	95
	Reductions for securities sold during the period	(2		)	(3		)
	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	$	69		$	92
Contractual maturity	'
	Contractual Maturity
		March 31, 2014						December 31, 2013
	(In millions)	Cost or			Estimated			Cost or		Estimated
		Amortized			Fair			Amortized		Fair
		Cost			Value			Cost		Value
	Due in one year or less	$	2,684		$	2,729		$	2,420	$	2,455
	Due after one year through five years	8,839			9,401			9,496		10,068
	Due after five years through ten years	11,455			11,876			11,667		11,954
	Due after ten years	13,920			15,394			15,692		16,720
	Total	$	36,898		$	39,400		$	39,275	$	41,197

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2014
Summary of Derivative Instruments [Abstract]	'
Summary of aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments	'
	Derivative Financial Instruments
	March 31, 2014	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Equity warrants	$	5	$	—	$	—
	December 31, 2013	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Equity warrants	$	5	$	—	$	—

Fair_Value_Tables

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Assets and liabilities measured at fair value on a recurring and nonrecurring basis	'
	Assets and liabilities measured at fair value on a recurring and nonrecurring basis are summarized below.
	March 31, 2014											Total
												Assets/(Liabilities)
	(In millions)	Level 1				Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	24			$	18,623		$	189		$	18,836
	States, municipalities and political subdivisions	—				11,769			86			11,855
	Asset-backed:
	Residential mortgage-backed	—				4,585			359			4,944
	Commercial mortgage-backed	—				1,927			126			2,053
	Other asset-backed	—				537			439			976
	Total asset-backed	—				7,049			924			7,973
	U.S. Treasury and obligations of government-sponsored enterprises	135				6			—			141
	Foreign government	76				500			—			576
	Redeemable preferred stock	23				11			—			34
	Total fixed maturity securities	258				37,958			1,199			39,415
	Equity securities	117				55			2			174
	Other invested assets	—				55			—			55
	Short term investments	1,353				651			—			2,004
	Life settlement contracts, included in Other assets	—				—			87			87
	Total recurring basis assets	1,728				38,719			1,288			41,735
	Assets held for sale - nonrecurring basis	—		—		3,486			—			3,486
	Total assets	$	1,728			$	42,205		$	1,288		$	45,221
	Liabilities
	Liabilities held for sale - nonrecurring basis	$	—			$	3,250		$	—		$	3,250
	Total liabilities	$	—			$	3,250		$	—		$	3,250
	December 31, 2013										Total
											Assets/(Liabilities)
	(In millions)	Level 1			Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	33		$	20,661		$	204		$	20,898
	States, municipalities and political subdivisions	—			11,486			71			11,557
	Asset-backed:
	Residential mortgage-backed	—			4,640			331			4,971
	Commercial mortgage-backed	—			1,912			151			2,063
	Other asset-backed	—			509			446			955
	Total asset-backed	—			7,061			928			7,989
	U.S. Treasury and obligations of government-sponsored enterprises	116			28			—			144
	Foreign government	81			462			—			543
	Redeemable preferred stock	45			57			—			102
	Total fixed maturity securities	275			39,755			1,203			41,233
	Equity securities	126			48			11			185
	Other invested assets	—			54			—			54
	Short term investments	769			563			—			1,332
	Life settlement contracts, included in Other assets	—			—			88			88
	Separate account business	9			171			1			181
	Total assets	$	1,179		$	40,591		$	1,303		$	43,073
Table of reconciliation for assets and liablities measured at fair value on a recurring basis using significant unobservable inputs	'
	The tables below present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended March 31, 2014 and 2013.
	Level 3	Balance at			Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at			Unrealized gains (losses) on Level 3 assets and liabilities held at March 31, 2014 recognized in net income (loss)*
	(In millions)	January 1,																		Level 3		of Level 3			March 31,
		2014																							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
	Level 3	Balance at			Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at			Unrealized gains (losses) on Level 3 assets and liabilities held at March 31, 2013 recognized in net income (loss)*
	(In millions)	January 1,																		Level 3		of Level 3			March 31,
		2013																							2013
	Fixed maturity securities:
	Corporate and other bonds	$	219		$	—		$	2		$	110		$	(17	)	$	(20	)	$	26	$	(18	)	$	302		$	(1	)
	States, municipalities and political subdivisions	96			(3		)	—			85			(47		)	(2		)	—		—			129			—
	Asset-backed:
	Residential mortgage-backed	413			3			—			61			—			(11		)	—		(16		)	450			—
	Commercial mortgage-backed	129			1			5			73			—			(7		)	—		(24		)	177			—
	Other asset-backed	368			3			1			136			(99		)	(13		)	—		—			396			—
	Total asset-backed	910			7			6			270			(99		)	(31		)	—		(40		)	1,023			—
	Redeemable preferred stock	26			—			—			—			—			—			—		—			26			—
	Total fixed maturity securities	1,251			4			8			465			(163		)	(53		)	26		(58		)	1,480			(1		)
	Equity securities	34			(15		)	1			—			—			—			—		(1		)	19			(15		)
	Other invested assets, including derivatives, net	—			—			—			—			(1		)	—			—		—			(1		)	—
	Short term investments	6			—			—			—			(1		)	—			—		—			5			—
	Life settlement contracts	100			7			—			—			—			(12		)	—		—			95			—
	Separate account business	2			—			—			—			—			—			—		—			2			—
	Total	$	1,393		$	(4	)	$	9		$	465		$	(165	)	$	(65	)	$	26	$	(59	)	$	1,600		$	(16	)
Quantitative information about significant unobservable inputs in the fair value measurement of level 3 assets	'
	The table below presents quantitative information about the significant unobservable inputs utilized by the Company in the fair value measurements of Level 3 assets. Valuations for assets and liabilities not presented in the table below are primarily based on broker/dealer quotes for which there is a lack of transparency as to inputs used to develop the valuations. The quantitative detail of these unobservable inputs is neither provided nor reasonably available to the Company.
	Assets	Fair Value at March 31, 2014			Valuation Technique		Unobservable Input(s)	Range
	(In millions)							(Weighted Average)
	Fixed maturity securities	$	116		Discounted cash flow		Credit spread	2% - 15% (4%)
	Equity securities	$	2		Market approach		Private offering price	$4,295 per share
	Life settlement contracts	$	87		Discounted cash flow		Discount rate risk premium	9%
							Mortality assumption	70% - 743% (191%)
	Assets	Fair Value at December 31, 2013			Valuation Technique		Unobservable Input(s)	Range
	(In millions)							(Weighted Average)
	Fixed maturity securities	$	142		Discounted cash flow		Credit spread	2% - 20% (4%)
	Equity securities	$	10		Market approach		Private offering price	$360 - $4,268 per share ($1,148)
	Life settlement contracts	$	88		Discounted cash flow		Discount rate risk premium	9%
							Mortality assumption	70% - 743% (192%)
Carrying amount and estimated fair value of financial instrument assets and liabilities not measured at fair value	'
	The carrying amount and estimated fair value of the Company's financial instrument assets and liabilities which are not measured at fair value on the Condensed Consolidated Balance Sheets are listed in the tables below.
	March 31, 2014	Carrying			Estimated Fair Value
	(In millions)	Amount			Level 1			Level 2			Level 3			Total
	Financial assets
	Notes receivable for the issuance of common stock	$	22		$	—		$	—		$	22		$	22
	Mortgage loans	495			—			—			510			510
	Financial liabilities
	Short term debt	$	549		—			569			—			569
	Long term debt	2,558			—			2,908			—			2,908
	December 31, 2013	Carrying			Estimated Fair Value
	(In millions)	Amount			Level 1			Level 2			Level 3			Total
	Financial assets
	Notes receivable for the issuance of common stock	$	23		$	—		$	—		$	23		$	23
	Mortgage loans	508			—			—			515			515
	Financial liabilities
	Premium deposits and annuity contracts	$	57		$	—		$	—		$	58		$	58
	Short term debt	549			—			575			—			575
	Long term debt	2,011			—			2,328			—			2,328

Claim_and_Claim_Adjustment_Exp1

Claim and Claim Adjustment Expense Reserves (Tables)	3 Months Ended
	Mar. 31, 2014
Claim and Claim Adjustment Expense Reserves [Abstract]	'
Net prior year development	'
	Net Prior Year Development
	Three months ended March 31, 2014
	(In millions)	CNA			CNA Commercial			Hardy			Corporate		Total
		Specialty									& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(2	)	$	17		$	10		$	—	$	25
	Pretax (favorable) unfavorable premium development	(8		)	(19		)	(4		)	—		(31		)
	Total pretax (favorable) unfavorable net prior year development	$	(10	)	$	(2	)	$	6		$	—	$	(6	)
	Three months ended March 31, 2013
	(In millions)	CNA			CNA Commercial			Hardy			Corporate		Total
		Specialty									& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(15	)	$	(11	)	$	(1	)	$	1	$	(26	)
	Pretax (favorable) unfavorable premium development	(8		)	(10		)	4			1		(13		)
	Total pretax (favorable) unfavorable net prior year development	$	(23	)	$	(21	)	$	3		$	2	$	(39	)
Net prior year claim and allocated claim adjustment expense reserve development for CNA Specialty segment	'
	Three months ended March 31
	(In millions)	2014			2013
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Medical Professional Liability	$	1		$	(3	)
	Other Professional Liability and Management Liability	(6		)	(1		)
	Surety	1			1
	Warranty	—			—
	Other	2			(12		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(2	)	$	(15	)
Net prior year claim and allocated claim adjustment expense reserve development for CNA Commercial segment	'
	Three months ended March 31
	(In millions)	2014			2013
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Commercial Auto	$	20		$	(5	)
	General Liability	(5		)	(21		)
	Workers' Compensation	10			25
	Property and Other	(8		)	(10		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	17		$	(11	)
Net prior year claim and allocated claim adjustment expense reserve development for Hardy segment	'
	Three months ended March 31
	(In millions)	2014			2013
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Marine and Aviation	$	5		$	(1	)
	Non-Marine Property	(2		)	—
	Property Treaty	(2		)	—
	Specialty	(1		)	—
	Commutations	10			—
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	10		$	(1	)

Benefit_Plans_Tables

Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2014
Compensation and Retirement Disclosure [Abstract]	'
Components of net periodic cost (benefit)	'
	Net Periodic Cost (Benefit)
	Three months ended March 31
	(In millions)	2014			2013
	Pension cost (benefit)
	Service cost	$	3		$	3
	Interest cost on projected benefit obligation	33			30
	Expected return on plan assets	(48		)	(45		)
	Amortization of net actuarial (gain) loss	6			12
	Net periodic pension cost (benefit)	$	(6	)	$	—
	Postretirement cost (benefit)
	Amortization of prior service credit	$	(4	)	$	(4	)
	Net periodic postretirement cost (benefit)	$	(4	)	$	(4	)

Other_Intangible_Assets_Tables

Other Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2014
Intangible Assets, Gross (Excluding Goodwill) [Abstract]	'
Schedule of Other Intangible Assets	'
	Other intangible assets are presented in the following table.
			31-Mar-14				31-Dec-13
	(In millions)	Economic Useful Life	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
	Finite-lived intangible assets:
	Value of business acquired	1 - 4 years	$	64	$	64	$	64	$	63
	Trade name	8 years	9		2		8		2
	Distribution channel	15 years	13		1		13		1
	Total finite-lived intangible assets		86		67		85		66
	Indefinite-lived intangible assets:
	Syndicate capacity		58				58
	Agency force		16				16
	Total indefinite-lived intangible assets		74				74
	Total other intangible assets		$	160	$	67	$	159	$	66

Business_Segments_Tables

Business Segments (Tables)	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Significant components of the Company's continuing operations and selected balance sheet items	'
	Three months ended March 31, 2014	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	748		$	822		$	98		$	139		$	—		$	(1	)	$	1,806
	Net investment income	151			198			1			171			5			—			526
	Other revenues	68			9			1			5			2			—			85
	Total operating revenues	967			1,029			100			315			7			(1		)	2,417
	Claims, Benefits and Expenses
	Net incurred claims and benefits	480			622			38			306			(3		)	—			1,443
	Policyholders’ dividends	1			2			—			—			—			—			3
	Amortization of deferred acquisition costs	153			140			28			8			—			—			329
	Other insurance related expenses	72			139			20			32			—			(1		)	262
	Other expenses	61			11			4			1			51			—			128
	Total claims, benefits and expenses	767			914			90			347			48			(1		)	2,165
	Operating income (loss) before income tax	200			115			10			(32		)	(41		)	—			252
	Income tax (expense) benefit on operating income (loss)	(66		)	(37		)	(3		)	30			14			—			(62		)
	Net operating income (loss)	134			78			7			(2		)	(27		)	—			190
	Net realized investment gains (losses), pretax	12			12			—			16			6			—			46
	Income tax (expense) benefit on net realized investment gains (losses)	(4		)	(4		)	—			(6		)	(2		)	—			(16		)
	Net realized investment gains (losses)	8			8			—			10			4			—			30
	Net income (loss) from continuing operations	$	142		$	86		$	7		$	8		$	(23	)	$	—		$	220
	March 31, 2014
	(In millions)
	Reinsurance receivables	$	555		$	1,050		$	153		$	401		$	2,940		$	—		$	5,099
	Insurance receivables	$	794		$	1,134		$	191		$	10		$	3		$	—		$	2,132
	Deferred acquisition costs	$	326		$	273		$	53		$	—		$	—		$	—		$	652
	Goodwill	$	117		$	—		$	38		$	—		$	—		$	—		$	155
	Insurance reserves
	Claim and claim adjustment expenses	$	6,786		$	10,574		$	377		$	3,085		$	3,111		$	—		$	23,933
	Unearned premiums	1,863			1,583			250			142			—			—			3,838
	Future policy benefits	—			—			—			8,254			—			—			8,254
	Policyholders’ funds	9			17			—			—			—			—			26
	Three months ended March 31, 2013	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Operating revenues
	Net earned premiums	$	723		$	837		$	64		$	141		$	—		$	(1	)	$	1,764
	Net investment income	170			250			1			162			8			—			591
	Other revenues	60			10			1			3			3			—			77
	Total operating revenues	953			1,097			66			306			11			(1		)	2,432
	Claims, Benefits and Expenses
	Net incurred claims and benefits	465			600			31			293			4			—			1,393
	Policyholders’ dividends	1			2			—			—			—			—			3
	Amortization of deferred acquisition costs	150			149			21			8			—			—			328
	Other insurance related expenses	71			143			16			32			—			(1		)	261
	Other expenses	54			9			7			5			46			—			121
	Total claims, benefits and expenses	741			903			75			338			50			(1		)	2,106
	Operating income (loss) before income tax	212			194			(9		)	(32		)	(39		)	—			326
	Income tax (expense) benefit on operating income (loss)	(72		)	(69		)	1			26			13			—			(101		)
	Net operating income (loss)	140			125			(8		)	(6		)	(26		)	—			225
	Net realized investment gains (losses), pretax	3			4			1			9			6			—			23
	Income tax (expense) benefit on net realized investment gains (losses)	(1		)	(1		)	—			(3		)	(2		)	—			(7		)
	Net realized investment gains (losses)	2			3			1			6			4			—			16
	Net income (loss) from continuing operations	$	142		$	128		$	(7	)	$	—		$	(22	)	$	—		$	241
	December 31, 2013
	(In millions)
	Reinsurance receivables	$	546		$	1,075		$	197		$	1,203		$	3,067		$	—		$	6,088
	Insurance receivables	$	775		$	1,099		$	176		$	11		$	2		$	—		$	2,063
	Deferred acquisition costs	$	318		$	257		$	49		$	—		$	—		$	—		$	624
	Goodwill	$	117		$	—		$	38		$	—		$	—		$	—		$	155
	Insurance reserves
	Claim and claim adjustment expenses	$	6,689		$	10,649		$	386		$	3,058		$	3,307		$	—		$	24,089
Unearned premiums	1,805			1,536			249			128			—			—			3,718
Future policy benefits	—			—			—			10,471			—			—			10,471
Policyholders’ funds	9			15			—			92			—			—			116
Revenues by line of business	'
	Revenues by Line of Business
	Three months ended March 31
	(In millions)	2014			2013
	CNA Specialty
	International	$	64		$	59
	Management & Professional Liability	704			700
	Surety	122			116
	Warranty & Alternative Risks	89			81
	CNA Specialty revenues	979			956
	CNA Commercial
	Commercial Insurance	762			826
	International	95			93
	Small Business	184			182
	CNA Commercial revenues	1,041			1,101
	Hardy revenues	100			67
	Life & Group Non-Core revenues	331			315
	Corporate & Other Non-Core revenues	13			17
	Eliminations	(1		)	(1		)
	Total revenues	$	2,463		$	2,455

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) by Component (Tables)	3 Months Ended
	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Accumulated Other Comprehensive Income (Loss) by Component	'
	The tables below display the changes in Accumulated other comprehensive income (loss) by component for the three months ended March 31, 2014 and 2013.
	(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 at 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 at March 31, 2014	$	33		$	912		$	30		$	(425	)	$	142		$	692
	(In millions)	Net unrealized gains (losses) on investments with OTTI losses			Net unrealized gains (losses) on other investments			Pension and postretirement benefits			Cumulative foreign currency translation adjustment			Total
	Balance at January 1, 2013	$	20		$	1,371		$	(721	)	$	161		$	831
	Other comprehensive income (loss) before reclassifications	14			(49		)	—			(61		)	(96		)
	Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(6), $3, $0, and $(3)	—			13			(5		)	—			8
	Other comprehensive income (loss) after tax (expense) benefit of $(7), $35, $(3), $0, and $25	14			(62		)	5			(61		)	(104		)
	Balance at March 31, 2013	$	34		$	1,309		$	(716	)	$	100		$	727

Assets_Liabilities_Held_for_Sa1

Assets & Liabilities Held for Sale and Discontinued Operations (Tables)	3 Months Ended
	Mar. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Detailed assets and liabilities held for sale and results of discontinued operations	'
	The following table presents the detailed assets and liabilities held for sale as of March 31, 2014:
	(In millions)	2014
	Assets
	Investments:
	Fixed maturity securities at fair value	$	2,684
	Equity securities at fair value	16
	Other invested assets	1
	Short term investments	36
	Total investments	2,737
	Cash	14
	Reinsurance receivables	787
	Other assets	55
	Separate account business	148
	Assets held for sale	3,741
	Less: Impairment on sale	(255		)
	Total assets held for sale	$	3,486
	Liabilities
	Insurance reserves	$	3,017
	Other liabilities	85
	Separate account business	148
	Total liabilities held for sale	$	3,250
	The results of discontinued operations reflected in the Condensed Consolidated Statements of Operations were as follows:
	Three months ended March 31
	(In millions)	2014			2013
	Revenues
	Net investment income	$	41		$	42
	Net realized investment gains	1			5
	Other revenues	—			1
	Total revenues	42			48
	Claims, Benefits and Expenses
	Insurance claims and policyholders' benefits	31			33
	Other operating expenses	1			1
	Total claims, benefits and expenses	32			34
	Income before income tax	10			14
	Income tax expense	(3		)	(5		)
	Income from operations of discontinued operations, net of income tax	7			9
	Impairment loss on sale, net of income tax benefit of $41 and -	(214		)	—
	(Loss) income from discontinued operations	$	(207	)	$	9

General_Narrative_Details

General (Narrative) (Details)	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Percentage owned of outstanding common stock by majority shareholder	90.00%

Earnings_Per_Share_Narrative_D

Earnings Per Share (Narrative) (Details)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]	'	'
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	660	372
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	110	335

Investments_Narrative_Details

Investments (Narrative) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Investments [Abstract]	'	'
Reduction of net unrealized gains on investments included in AOCI due to shadow adjustments	$712	$532
Future capital call commitments for limited partnership investments	384	'
Mortgage Loan Commitments	59	'
Commitments to purchase or fund privately placed debt securities	154	'
Commitments to sell various privately placed debt securities	$180	'

Investments_Net_investment_inc

Investments (Net investment income) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net Investment Income [Line Items]	'	'
Gross investment income	$539	$603
Investment expense	-13	-12
Net investment income	526	591
Fixed maturity securities [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	452	457
Short term investments [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	1	1
Limited partnership investments [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	73	131
Equity securities [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	2	3
Mortgage loans [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	6	5
Trading portfolio [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	3	5
Other [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	$2	$1

Investments_Net_realized_inves

Investments (Net realized investment gains (losses)) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net realized investment gains (losses)	$46	$23
Fixed maturity securities [Member]	'	'
Gross realized gains	53	39
Gross realized losses	-15	-12
Net realized investment gains (losses)	38	27
Equity securities [Member]	'	'
Gross realized gains	5	2
Gross realized losses	'	-15
Net realized investment gains (losses)	5	-13
Derivative [Member]	'	'
Net realized investment gains (losses)	'	2
Short term investments and other [Member]	'	'
Net realized investment gains (losses)	$3	$7

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, 2014	Mar. 31, 2013
Other-than-temporary impairment losses recognized in earnings	$2	$18
Corporate and other bonds [Member]	'	'
Other-than-temporary impairment losses recognized in earnings	1	3
Residential mortgage-backed [Member]	'	'
Other-than-temporary impairment losses recognized in earnings	1	'
Total fixed maturity securities available-for-sale [Member]	'	'
Other-than-temporary impairment losses recognized in earnings	2	3
Preferred stock [Member]	'	'
Other-than-temporary impairment losses recognized in earnings	'	$15

Investments_Summary_of_fixed_m

Investments (Summary of fixed maturity and equity securities) (Details) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Cost or Amortized Cost	$37,076	$39,490
Gross Unrealized Gains	2,781	2,460
Gross Unrealized Losses	268	532
Estimated fair value	39,589	41,418
Corporate and other bonds [Member]	'	'
Cost or Amortized Cost	17,265	19,352
Gross Unrealized Gains	1,612	1,645
Gross Unrealized Losses	56	135
Estimated fair value	18,821	20,862
Unrealized OTTI Losses (Gains)	'	'
States, municipalities and political subdivisions [Member]	'	'
Cost or Amortized Cost	11,113	11,281
Gross Unrealized Gains	871	548
Gross Unrealized Losses	129	272
Estimated fair value	11,855	11,557
Unrealized OTTI Losses (Gains)	'	'
Residential mortgage-backed [Member]	'	'
Cost or Amortized Cost	4,854	4,940
Gross Unrealized Gains	156	123
Gross Unrealized Losses	66	92
Estimated fair value	4,944	4,971
Unrealized OTTI Losses (Gains)	-47	-37
Commercial mortgage-backed [Member]	'	'
Cost or Amortized Cost	1,974	1,995
Gross Unrealized Gains	92	90
Gross Unrealized Losses	13	22
Estimated fair value	2,053	2,063
Unrealized OTTI Losses (Gains)	-3	-3
Other asset-backed [Member]	'	'
Cost or Amortized Cost	966	945
Gross Unrealized Gains	12	13
Gross Unrealized Losses	2	3
Estimated fair value	976	955
Unrealized OTTI Losses (Gains)	'	'
Total asset-backed [Member]	'	'
Cost or Amortized Cost	7,794	7,880
Gross Unrealized Gains	260	226
Gross Unrealized Losses	81	117
Estimated fair value	7,973	7,989
Unrealized OTTI Losses (Gains)	-50	-40
U.S. Treasury and obligations of government-sponsored enterprises [Member]	'	'
Cost or Amortized Cost	135	139
Gross Unrealized Gains	7	6
Gross Unrealized Losses	1	1
Estimated fair value	141	144
Unrealized OTTI Losses (Gains)	'	'
Foreign Government [Member]	'	'
Cost or Amortized Cost	559	531
Gross Unrealized Gains	18	15
Gross Unrealized Losses	1	3
Estimated fair value	576	543
Unrealized OTTI Losses (Gains)	'	'
Redeemable preferred stock [Member]	'	'
Cost or Amortized Cost	32	92
Gross Unrealized Gains	2	10
Gross Unrealized Losses	'	'
Estimated fair value	34	102
Unrealized OTTI Losses (Gains)	'	'
Total fixed maturity securities available-for-sale [Member]	'	'
Cost or Amortized Cost	36,898	39,275
Gross Unrealized Gains	2,770	2,450
Gross Unrealized Losses	268	528
Estimated fair value	39,400	41,197
Unrealized OTTI Losses (Gains)	-50	-40
Total fixed maturity securities trading [Member]	'	'
Cost or Amortized Cost, Trading Securities	15	36
Gross Unrealized Gains, Trading Securities	'	'
Gross Unrealized Losses, Trading Securities	'	'
Estimated Fair Value, Trading Securities	15	36
Common stock [Member]	'	'
Cost or Amortized Cost	33	36
Gross Unrealized Gains	9	9
Gross Unrealized Losses	'	'
Estimated fair value	42	45
Preferred stock [Member]	'	'
Cost or Amortized Cost	130	143
Gross Unrealized Gains	2	1
Gross Unrealized Losses	'	4
Estimated fair value	132	140
Total equity securities available-for-sale [Member]	'	'
Cost or Amortized Cost	163	179
Gross Unrealized Gains	11	10
Gross Unrealized Losses	'	4
Estimated fair value	$174	$185

Investments_Securities_in_a_gr

Investments (Securities in a gross unrealized loss position) (Details) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	$4,903	$9,256
Gross Unrealized Losses, Less than 12 Months	133	388
Estimated Fair Value, 12 Months or Longer	801	544
Gross Unrealized Losses, 12 Months or Longer	135	144
Estimated Fair Value, Total	5,704	9,800
Gross Unrealized Losses, Total	268	532
Corporate and other bonds [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	2,002	3,592
Gross Unrealized Losses, Less than 12 Months	48	129
Estimated Fair Value, 12 Months or Longer	109	72
Gross Unrealized Losses, 12 Months or Longer	8	6
Estimated Fair Value, Total	2,111	3,664
Gross Unrealized Losses, Total	56	135
States, municipalities and political subdivisions [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	1,397	3,251
Gross Unrealized Losses, Less than 12 Months	56	197
Estimated Fair Value, 12 Months or Longer	244	129
Gross Unrealized Losses, 12 Months or Longer	73	75
Estimated Fair Value, Total	1,641	3,380
Gross Unrealized Losses, Total	129	272
Residential mortgage-backed [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	739	1,293
Gross Unrealized Losses, Less than 12 Months	13	29
Estimated Fair Value, 12 Months or Longer	347	343
Gross Unrealized Losses, 12 Months or Longer	53	63
Estimated Fair Value, Total	1,086	1,636
Gross Unrealized Losses, Total	66	92
Commercial mortgage-backed [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	515	640
Gross Unrealized Losses, Less than 12 Months	12	22
Estimated Fair Value, 12 Months or Longer	91	'
Gross Unrealized Losses, 12 Months or Longer	1	'
Estimated Fair Value, Total	606	640
Gross Unrealized Losses, Total	13	22
Other asset-backed [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	167	269
Gross Unrealized Losses, Less than 12 Months	2	3
Estimated Fair Value, 12 Months or Longer	3	'
Gross Unrealized Losses, 12 Months or Longer	'	'
Estimated Fair Value, Total	170	269
Gross Unrealized Losses, Total	2	3
Total asset-backed [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	1,421	2,202
Gross Unrealized Losses, Less than 12 Months	27	54
Estimated Fair Value, 12 Months or Longer	441	343
Gross Unrealized Losses, 12 Months or Longer	54	63
Estimated Fair Value, Total	1,862	2,545
Gross Unrealized Losses, Total	81	117
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	6	13
Gross Unrealized Losses, Less than 12 Months	1	1
Estimated Fair Value, 12 Months or Longer	3	'
Gross Unrealized Losses, 12 Months or Longer	'	'
Estimated Fair Value, Total	9	13
Gross Unrealized Losses, Total	1	1
Foreign Government [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	61	111
Gross Unrealized Losses, Less than 12 Months	1	3
Estimated Fair Value, 12 Months or Longer	4	'
Gross Unrealized Losses, 12 Months or Longer	'	'
Estimated Fair Value, Total	65	111
Gross Unrealized Losses, Total	1	3
Total fixed maturity securities available-for-sale [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	4,887	9,169
Gross Unrealized Losses, Less than 12 Months	133	384
Estimated Fair Value, 12 Months or Longer	801	544
Gross Unrealized Losses, 12 Months or Longer	135	144
Estimated Fair Value, Total	5,688	9,713
Gross Unrealized Losses, Total	268	528
Preferred stock [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	16	87
Gross Unrealized Losses, Less than 12 Months	'	4
Estimated Fair Value, 12 Months or Longer	'	'
Gross Unrealized Losses, 12 Months or Longer	'	'
Estimated Fair Value, Total	16	87
Gross Unrealized Losses, Total	'	$4

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, 2014	Mar. 31, 2013
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]	'	'
Beginning balance of credit losses on fixed maturity securities	$74	$95
Reductions for securities sold during the period	-2	-3
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	$69	$92

Investments_Contractual_maturi

Investments (Contractual maturity) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Investments [Abstract]	'	'
Due in one year or less, cost or amortized cost	$2,684	$2,420
Due after one year through five years, cost or amortized cost	8,839	9,496
Due after five years through ten years, cost or amortized cost	11,455	11,667
Due after ten years, cost or amortized cost	13,920	15,692
Total Amortized Cost Basis	36,898	39,275
Due in one year or less, estimated fair value	2,729	2,455
Due after one year through five years, estimated fair value	9,401	10,068
Due after five years through ten years, estimated fair value	11,876	11,954
Due after ten years, estimated fair value	15,394	16,720
Total Estimated Fair Value	$39,400	$41,197

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Narrative) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Summary of Derivative Instruments [Abstract]	'	'
Derivative transactions entered into	$67	$604
Derivative transactions terminated	$67	$542

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Summary of aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments) (Details) (Not Designated as Hedging Instrument [Member], Equity warrants [Member], USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Not Designated as Hedging Instrument [Member] | Equity warrants [Member]	'	'
Derivative [Line Items]	'	'
Contractual/notional amount	$5	$5
Estimated fair value asset	'	'
Estimated fair value (liability)	'	'

Fair_Value_Assets_and_liabilit

Fair Value (Assets and liabilities measured at fair value on a recurring and nonrecurring basis) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
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	$41,735	$43,073
Assets, Fair Value Disclosure	45,221	43,073
Liabilities, Fair Value Disclosure, Nonrecurring	3,250	'
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	18,836	20,898
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	11,855	11,557
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	4,944	4,971
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	2,053	2,063
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	976	955
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	7,973	7,989
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	141	144
Foreign Government [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	576	543
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	34	102
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	39,415	41,233
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	174	185
Other invested assets [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	55	54
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	2,004	1,332
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	87	88
Separate account business [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	181
Assets held for sale-nonrecurring basis [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Nonrecurring	3,486	'
Liabilities held for sale-nonrecurring basis [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Liabilities, Fair Value Disclosure, Nonrecurring	3,250	'
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	1,728	1,179
Assets, Fair Value Disclosure	1,728	1,179
Liabilities, Fair Value Disclosure, Nonrecurring	'	'
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	24	33
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	'	'
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	'	'
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	'	'
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	'	'
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	'	'
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	135	116
Level 1 [Member] | Foreign Government [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	76	81
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	23	45
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	258	275
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	117	126
Level 1 [Member] | Other invested assets [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
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	1,353	769
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	'	'
Level 1 [Member] | Separate account business [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	9
Level 1 [Member] | Assets held for sale-nonrecurring basis [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Nonrecurring	'	'
Level 1 [Member] | Liabilities held for sale-nonrecurring basis [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Liabilities, Fair Value Disclosure, Nonrecurring	'	'
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	38,719	40,591
Assets, Fair Value Disclosure	42,205	40,591
Liabilities, Fair Value Disclosure, Nonrecurring	3,250	'
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	18,623	20,661
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	11,769	11,486
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	4,585	4,640
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	1,927	1,912
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	537	509
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	7,049	7,061
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	6	28
Level 2 [Member] | Foreign Government [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	500	462
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	11	57
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	37,958	39,755
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	55	48
Level 2 [Member] | Other invested assets [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	55	54
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	651	563
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	'	'
Level 2 [Member] | Separate account business [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	171
Level 2 [Member] | Assets held for sale-nonrecurring basis [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Nonrecurring	3,486	'
Level 2 [Member] | Liabilities held for sale-nonrecurring basis [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Liabilities, Fair Value Disclosure, Nonrecurring	3,250	'
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	1,288	1,303
Assets, Fair Value Disclosure	1,288	1,303
Liabilities, Fair Value Disclosure, Nonrecurring	'	'
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	189	204
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	71
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	359	331
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	126	151
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	439	446
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	924	928
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	'	'
Level 3 [Member] | Foreign Government [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
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	'	'
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	1,199	1,203
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	2	11
Level 3 [Member] | Other invested assets [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
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	'	'
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	87	88
Level 3 [Member] | Separate account business [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	1
Level 3 [Member] | Assets held for sale-nonrecurring basis [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Disclosure, Nonrecurring	'	'
Level 3 [Member] | Liabilities held for sale-nonrecurring basis [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Liabilities, Fair Value Disclosure, Nonrecurring	'	'

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, 2014	Mar. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	$1,303	$1,393
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	17	-4
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	12	9
Purchases	178	465
Sales	-95	-165
Settlements	-110	-65
Transfers into Level 3	38	26
Transfers out of Level 3	-55	-59
Balance, Ending, Assets	1,288	1,600
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	1	-16
Fixed maturity securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	1,203	1,251
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	4	4
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	16	8
Purchases	178	465
Sales	-87	-163
Settlements	-99	-53
Transfers into Level 3	38	26
Transfers out of Level 3	-54	-58
Balance, Ending, Assets	1,199	1,480
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	-1
Corporate and other bonds [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	204	219
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	1	'
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	1	2
Purchases	5	110
Sales	-4	-17
Settlements	-5	-20
Transfers into Level 3	3	26
Transfers out of Level 3	-16	-18
Balance, Ending, Assets	189	302
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	-1
States, municipalities and political subdivisions [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	71	96
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	'	-3
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	1	'
Purchases	'	85
Sales	'	-47
Settlements	'	-2
Transfers into Level 3	14	'
Transfers out of Level 3	'	'
Balance, Ending, Assets	86	129
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Residential mortgage-backed [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	331	413
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	1	3
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	15	'
Purchases	25	61
Sales	'	'
Settlements	-21	-11
Transfers into Level 3	21	'
Transfers out of Level 3	-13	-16
Balance, Ending, Assets	359	450
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Commercial Mortgage Backed Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	151	129
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	5
Purchases	'	73
Sales	'	'
Settlements	-1	-7
Transfers into Level 3	'	'
Transfers out of Level 3	-24	-24
Balance, Ending, Assets	126	177
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Other asset-backed [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	446	368
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	1	3
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	'	1
Purchases	148	136
Sales	-83	-99
Settlements	-72	-13
Transfers into Level 3	'	'
Transfers out of Level 3	-1	'
Balance, Ending, Assets	439	396
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Total asset-backed [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	928	910
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	3	7
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	14	6
Purchases	173	270
Sales	-83	-99
Settlements	-94	-31
Transfers into Level 3	21	'
Transfers out of Level 3	-38	-40
Balance, Ending, Assets	924	1,023
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Redeemable preferred stock [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	'	26
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 Level 3	'	'
Transfers out of Level 3	'	'
Balance, Ending, Assets	'	26
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Equity securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	11	34
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	3	-15
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-4	1
Purchases	'	'
Sales	-8	'
Settlements	'	'
Transfers into Level 3	'	'
Transfers out of Level 3	'	-1
Balance, Ending, Assets	2	19
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	-15
Other invested assets, including derivatives, net [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	'	'
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	'	'
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	'	'
Purchases	'	'
Sales	'	-1
Settlements	'	'
Transfers into Level 3	'	'
Transfers out of Level 3	'	'
Balance, Ending, Assets	'	-1
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Short term investments [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	'	6
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	'	'
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	'	'
Purchases	'	'
Sales	'	-1
Settlements	'	'
Transfers into Level 3	'	'
Transfers out of Level 3	'	'
Balance, Ending, Assets	'	5
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Life settlement contracts, included in Other assets [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	88	100
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	10	7
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	'	'
Purchases	'	'
Sales	'	'
Settlements	-11	-12
Transfers into Level 3	'	'
Transfers out of Level 3	'	'
Balance, Ending, Assets	87	95
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	1	'
Separate account business [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	1	2
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 Level 3	'	'
Transfers out of Level 3	-1	'
Balance, Ending, Assets	'	2
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'

Fair_Value_Narrative_Details

Fair Value (Narrative) (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]	'	'
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	$23	'
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$1	'

Fair_Value_Quantitative_inform

Fair Value (Quantitative information about significant unobservable inputs in the fair value measurement of level 3 assets) (Details) (USD $)	3 Months Ended	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Assets, Fair Value Disclosure	45,221	43,073
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Assets, Fair Value Disclosure	116	142
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	15.00%	20.00%
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Credit spread	4.00%	4.00%
Equity securities [Member] | Market Approach Valuation Technique [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Assets, Fair Value Disclosure	2	10
Private offering price	4,295	'
Equity securities [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Private offering price	'	360
Equity securities [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Private offering price	'	4,268
Equity securities [Member] | Market Approach Valuation Technique [Member] | Weighted Average [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Private offering price	'	1,148
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	87	88
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	70.00%	70.00%
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	743.00%	743.00%
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	191.00%	192.00%
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%
Level 1 [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Assets, Fair Value Disclosure	1,728	1,179
Level 2 [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Assets, Fair Value Disclosure	42,205	40,591
Level 3 [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Assets, Fair Value Disclosure	1,288	1,303

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, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	$22	$23
Mortgage loans	495	508
Financial Liabilities [Abstract]	'	'
Short term debt	549	549
Long term debt	2,558	2,011
Carrying Amount [Member]	'	'
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	22	23
Mortgage loans	495	508
Financial Liabilities [Abstract]	'	'
Premium deposits and annuity contracts	'	57
Short term debt	549	549
Long term debt	2,558	2,011
Estimated Fair Value [Member]	'	'
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	22	23
Mortgage loans	510	515
Financial Liabilities [Abstract]	'	'
Premium deposits and annuity contracts	'	58
Short term debt	569	575
Long term debt	2,908	2,328
Level 1 [Member] | Estimated Fair Value [Member]	'	'
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	'	'
Mortgage loans	'	'
Financial Liabilities [Abstract]	'	'
Premium deposits and annuity contracts	'	'
Short term debt	'	'
Long term debt	'	'
Level 2 [Member] | Estimated Fair Value [Member]	'	'
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	'	'
Mortgage loans	'	'
Financial Liabilities [Abstract]	'	'
Premium deposits and annuity contracts	'	'
Short term debt	569	575
Long term debt	2,908	2,328
Level 3 [Member] | Estimated Fair Value [Member]	'	'
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	22	23
Mortgage loans	510	515
Financial Liabilities [Abstract]	'	'
Premium deposits and annuity contracts	'	58
Short term debt	'	'
Long term debt	'	'

Claim_and_Claim_Adjustment_Exp2

Claim and Claim Adjustment Expense Reserves (Narrative) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Claim and Claim Adjustment Expense Reserves [Abstract]	'	'
Catastrophe losses net of reinsurance	$74	$39

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, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]	'	'
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	$25	($26)
Pretax (favorable) unfavorable premium development, excluding Life & Group	-31	-13
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-6	-39
CNA Specialty [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	-2	-15
Pretax (favorable) unfavorable premium development, excluding Life & Group	-8	-8
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-10	-23
CNA Commercial [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	17	-11
Pretax (favorable) unfavorable premium development, excluding Life & Group	-19	-10
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-2	-21
Hardy [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	10	-1
Pretax (favorable) unfavorable premium development, excluding Life & Group	-4	4
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	6	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	'	1
Pretax (favorable) unfavorable premium development, excluding Life & Group	'	1
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	'	$2

Claim_and_Claim_Adjustment_Exp4

Claim and Claim Adjustment Expense Reserves (Net prior year claim and allocated claim adjustment expense reserve development for CNA Specialty segment) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	$25	($26)
CNA Specialty [Member]	'	'
Medical Professional Liability	1	-3
Other Professional Liability and Management Liability	-6	-1
Surety	1	1
Warranty	'	'
Other	2	-12
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($2)	($15)

Claim_and_Claim_Adjustment_Exp5

Claim and Claim Adjustment Expense Reserves (Net prior year claim and allocated claim adjustment expense reserve development for CNA Commercial segment) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	$25	($26)
CNA Commercial [Member]	'	'
Commercial Auto	20	-5
General Liability	-5	-21
Workers' Compensation	10	25
Property and Other	-8	-10
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	$17	($11)

Claim_and_Claim_Adjustment_Exp6

Claim and Claim Adjustment Expense Reserves Net prior year claim and allocated claim adjustment expense reserve development for Hardy segment (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	$25	($26)
Hardy [Member]	'	'
Marine and Aviation	5	-1
Non-Marine Property	-2	'
Property Treaty	-2	'
Specialty	-1	'
Commutations	10	'
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	$10	($1)

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, 2014	Mar. 31, 2013
Pension Plans, Defined Benefit [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Service cost	$3	$3
Interest cost on projected benefit obligation	33	30
Expected return on plan assets	-48	-45
Amortization of net actuarial (gain) loss	6	12
Net periodic cost (benefit)	-6	'
Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Amortization of prior service credit	-4	-4
Net periodic cost (benefit)	($4)	($4)

Schedule_of_Other_Intangible_A

Schedule of Other Intangible Assets (Narrative) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Amortization of deferred acquisition costs	$329	$328
Finite-Lived Intangible Assets, Amortization Expense, Year Two	1	'
Finite-Lived Intangible Assets, Amortization Expense, Year Three	2	'
Finite-Lived Intangible Assets, Amortization Expense, Year Four	2	'
Finite-Lived Intangible Assets, Amortization Expense, Year Five	2	'
Hardy [Member]	'	'
Amortization of deferred acquisition costs	28	21
Other Intangible Assets [Member] | Hardy [Member]	'	'
Amortization of deferred acquisition costs	1	9
Amortization expense included in other operating expenses	'	$3

Schedule_of_Other_Intangible_A1

Schedule of Other Intangible Assets (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Indefinite-lived intangible assets	$74	$74
Finite-Lived Intangible Assets	86	85
Accumulated Amortization	67	66
Total other intangible assets	160	159
Total intangible assets, accumulated amortization	67	66
Lloyds syndicate capacity [Member]	'	'
Indefinite-lived intangible assets	58	58
Agency Force [Member]	'	'
Indefinite-lived intangible assets	16	16
Value of business acquired [Member]	'	'
Finite-Lived Intangible Assets	64	64
Accumulated Amortization	64	63
Trade name [Member]	'	'
Economic useful life measured in years	'8 years	'
Finite-Lived Intangible Assets	9	8
Accumulated Amortization	2	2
Distribution channel [Member]	'	'
Economic useful life measured in years	'15 years	'
Finite-Lived Intangible Assets	13	13
Accumulated Amortization	$1	$1
Minimum [Member] | Value of business acquired [Member]	'	'
Economic useful life measured in years	'1 year	'
Maximum [Member] | Value of business acquired [Member]	'	'
Economic useful life measured in years	'4 years	'

Commitments_Contingencies_and_1

Commitments, Contingencies, and Guarantees (Narrative) (Detail) (USD $)	Mar. 31, 2014
In Millions, unless otherwise specified
Recorded liabilities related to indemnification agreements	$7
Property Lease Guarantee [Member]	'
Aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third party loans	77
Indemnification Agreement [Member]	'
Aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third party loans	$702

Business_Segments_Income_State

Business Segments (Income Statement Information) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Operating Revenues	'	'
Net earned premiums	$1,806	$1,764
Net investment income	526	591
Other revenues	85	77
Total operating revenues	2,417	2,432
Claims, Benefits and Expenses	'	'
Net incurred claims and benefits	1,443	1,393
Policyholders' dividends	3	3
Amortization of deferred acquisition costs	329	328
Other insurance related expenses	262	261
Other expenses	128	121
Total claims, benefits and expenses	2,165	2,106
Operating income (loss) before income tax	252	326
Income tax (expense) benefit on operating income (loss)	-62	-101
Net operating income (loss)	190	225
Net realized investment gains (losses), pre-tax	46	23
Income tax (expense) benefit on net realized investment gains (losses)	-16	-7
Net realized investment gains (losses)	30	16
Net income (loss) from continuing operations	220	241
CNA Specialty [Member]	'	'
Operating Revenues	'	'
Net earned premiums	748	723
Net investment income	151	170
Other revenues	68	60
Total operating revenues	967	953
Claims, Benefits and Expenses	'	'
Net incurred claims and benefits	480	465
Policyholders' dividends	1	1
Amortization of deferred acquisition costs	153	150
Other insurance related expenses	72	71
Other expenses	61	54
Total claims, benefits and expenses	767	741
Operating income (loss) before income tax	200	212
Income tax (expense) benefit on operating income (loss)	-66	-72
Net operating income (loss)	134	140
Net realized investment gains (losses), pre-tax	12	3
Income tax (expense) benefit on net realized investment gains (losses)	-4	-1
Net realized investment gains (losses)	8	2
Net income (loss) from continuing operations	142	142
CNA Commercial [Member]	'	'
Operating Revenues	'	'
Net earned premiums	822	837
Net investment income	198	250
Other revenues	9	10
Total operating revenues	1,029	1,097
Claims, Benefits and Expenses	'	'
Net incurred claims and benefits	622	600
Policyholders' dividends	2	2
Amortization of deferred acquisition costs	140	149
Other insurance related expenses	139	143
Other expenses	11	9
Total claims, benefits and expenses	914	903
Operating income (loss) before income tax	115	194
Income tax (expense) benefit on operating income (loss)	-37	-69
Net operating income (loss)	78	125
Net realized investment gains (losses), pre-tax	12	4
Income tax (expense) benefit on net realized investment gains (losses)	-4	-1
Net realized investment gains (losses)	8	3
Net income (loss) from continuing operations	86	128
Hardy [Member]	'	'
Operating Revenues	'	'
Net earned premiums	98	64
Net investment income	1	1
Other revenues	1	1
Total operating revenues	100	66
Claims, Benefits and Expenses	'	'
Net incurred claims and benefits	38	31
Policyholders' dividends	'	'
Amortization of deferred acquisition costs	28	21
Other insurance related expenses	20	16
Other expenses	4	7
Total claims, benefits and expenses	90	75
Operating income (loss) before income tax	10	-9
Income tax (expense) benefit on operating income (loss)	-3	1
Net operating income (loss)	7	-8
Net realized investment gains (losses), pre-tax	'	1
Income tax (expense) benefit on net realized investment gains (losses)	'	'
Net realized investment gains (losses)	'	1
Net income (loss) from continuing operations	7	-7
Life and Group Non-Core [Member]	'	'
Operating Revenues	'	'
Net earned premiums	139	141
Net investment income	171	162
Other revenues	5	3
Total operating revenues	315	306
Claims, Benefits and Expenses	'	'
Net incurred claims and benefits	306	293
Policyholders' dividends	'	'
Amortization of deferred acquisition costs	8	8
Other insurance related expenses	32	32
Other expenses	1	5
Total claims, benefits and expenses	347	338
Operating income (loss) before income tax	-32	-32
Income tax (expense) benefit on operating income (loss)	30	26
Net operating income (loss)	-2	-6
Net realized investment gains (losses), pre-tax	16	9
Income tax (expense) benefit on net realized investment gains (losses)	-6	-3
Net realized investment gains (losses)	10	6
Net income (loss) from continuing operations	8	'
Corporate and Other Non-Core [Member]	'	'
Operating Revenues	'	'
Net earned premiums	'	'
Net investment income	5	8
Other revenues	2	3
Total operating revenues	7	11
Claims, Benefits and Expenses	'	'
Net incurred claims and benefits	-3	4
Policyholders' dividends	'	'
Amortization of deferred acquisition costs	'	'
Other insurance related expenses	'	'
Other expenses	51	46
Total claims, benefits and expenses	48	50
Operating income (loss) before income tax	-41	-39
Income tax (expense) benefit on operating income (loss)	14	13
Net operating income (loss)	-27	-26
Net realized investment gains (losses), pre-tax	6	6
Income tax (expense) benefit on net realized investment gains (losses)	-2	-2
Net realized investment gains (losses)	4	4
Net income (loss) from continuing operations	-23	-22
Eliminations [Member]	'	'
Operating Revenues	'	'
Net earned premiums	-1	-1
Net investment income	'	'
Other revenues	'	'
Total operating revenues	-1	-1
Claims, Benefits and Expenses	'	'
Net incurred claims and benefits	'	'
Policyholders' dividends	'	'
Amortization of deferred acquisition costs	'	'
Other insurance related expenses	-1	-1
Other expenses	'	'
Total claims, benefits and expenses	-1	-1
Operating income (loss) before income tax	0	'
Income tax (expense) benefit on operating income (loss)	'	'
Net operating income (loss)	'	'
Net realized investment gains (losses), pre-tax	'	'
Income tax (expense) benefit on net realized investment gains (losses)	'	'
Net realized investment gains (losses)	'	'
Net income (loss) from continuing operations	'	'

Business_Segments_Balance_Shee

Business Segments (Balance Sheet Information) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	$5,099	$6,088
Insurance receivables	2,132	2,063
Deferred acquisition costs	652	624
Goodwill	155	155
Insurance reserves	'	'
Claim and claim adjustment expenses	23,933	24,089
Unearned premiums	3,838	3,718
Future policy benefits	8,254	10,471
Policyholders’ funds	26	116
CNA Specialty [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	555	546
Insurance receivables	794	775
Deferred acquisition costs	326	318
Goodwill	117	117
Insurance reserves	'	'
Claim and claim adjustment expenses	6,786	6,689
Unearned premiums	1,863	1,805
Future policy benefits	'	'
Policyholders’ funds	9	9
CNA Commercial [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	1,050	1,075
Insurance receivables	1,134	1,099
Deferred acquisition costs	273	257
Goodwill	'	'
Insurance reserves	'	'
Claim and claim adjustment expenses	10,574	10,649
Unearned premiums	1,583	1,536
Future policy benefits	'	'
Policyholders’ funds	17	15
Hardy [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	153	197
Insurance receivables	191	176
Deferred acquisition costs	53	49
Goodwill	38	38
Insurance reserves	'	'
Claim and claim adjustment expenses	377	386
Unearned premiums	250	249
Future policy benefits	'	'
Policyholders’ funds	'	'
Life and Group Non-Core [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	401	1,203
Insurance receivables	10	11
Deferred acquisition costs	'	'
Goodwill	'	'
Insurance reserves	'	'
Claim and claim adjustment expenses	3,085	3,058
Unearned premiums	142	128
Future policy benefits	8,254	10,471
Policyholders’ funds	'	92
Corporate and Other Non-Core [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	2,940	3,067
Insurance receivables	3	2
Deferred acquisition costs	'	'
Goodwill	'	'
Insurance reserves	'	'
Claim and claim adjustment expenses	3,111	3,307
Unearned premiums	'	'
Future policy benefits	'	'
Policyholders’ funds	'	'
Eliminations [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	'	'
Insurance receivables	'	'
Deferred acquisition costs	'	'
Goodwill	'	'
Insurance reserves	'	'
Claim and claim adjustment expenses	'	'
Unearned premiums	'	'
Future policy benefits	'	'
Policyholders’ funds	'	'

Business_Segments_Revenues_by_

Business Segments (Revenues by Line of Business) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Revenues	$2,463	$2,455
CNA Specialty [Domain]	'	'
Revenues	979	956
International - Specialty [Member]	'	'
Revenues	64	59
Management & Professional Liability [Member]	'	'
Revenues	704	700
Surety [Member]	'	'
Revenues	122	116
Warranty & Alternative Risks [Member]	'	'
Revenues	89	81
CNA Commercial [Domain]	'	'
Revenues	1,041	1,101
Commercial Insurance [Member]	'	'
Revenues	762	826
International - Commercial [Member]	'	'
Revenues	95	93
Small Business [Member]	'	'
Revenues	184	182
Hardy [Domain]	'	'
Revenues	100	67
Life and Group Non-Core [Member]	'	'
Revenues	331	315
Corporate and Other Non-Core [Member]	'	'
Revenues	13	17
Eliminations [Member]	'	'
Revenues	($1)	($1)

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) by Component (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated other comprehensive income (loss), beginning balance	$442	$831
Transfer to net assets held for sale	'	'
Other comprehensive income (loss), before reclassifications	276	-96
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	26	8
Other Comprehensive Income (loss), net of tax	250	-104
Accumulated other comprehensive income (loss), ending balance	692	727
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	-13	-3
Tax (expense) benefit on other comprehensive income (loss)	-139	25
Net unrealized gains (losses) on investments with OTTI losses [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated other comprehensive income (loss), beginning balance	26	20
Transfer to net assets held for sale	-5	'
Other comprehensive income (loss), before reclassifications	12	14
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	'	'
Other Comprehensive Income (loss), net of tax	12	14
Accumulated other comprehensive income (loss), ending balance	33	34
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	'	'
Tax (expense) benefit on other comprehensive income (loss)	-6	-7
Net unrealized gains (losses) on other investments [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated other comprehensive income (loss), beginning balance	692	1,371
Transfer to net assets held for sale	-17	'
Other comprehensive income (loss), before reclassifications	264	-49
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	27	13
Other Comprehensive Income (loss), net of tax	237	-62
Accumulated other comprehensive income (loss), ending balance	912	1,309
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	-14	-6
Tax (expense) benefit on other comprehensive income (loss)	-127	35
Net unrealized gains (losses) on discontinued operations [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated other comprehensive income (loss), beginning balance	'	'
Transfer to net assets held for sale	22	'
Other comprehensive income (loss), before reclassifications	8	'
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	'	'
Other Comprehensive Income (loss), net of tax	8	'
Accumulated other comprehensive income (loss), ending balance	30	'
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	'	'
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	-426	-721
Transfer to net assets held for sale	'	'
Other comprehensive income (loss), before reclassifications	'	'
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	-1	-5
Other Comprehensive Income (loss), net of tax	1	5
Accumulated other comprehensive income (loss), ending balance	-425	-716
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	1	3
Tax (expense) benefit on other comprehensive income (loss)	-1	-3
Cumulative foreign currency translation adjustment [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated other comprehensive income (loss), beginning balance	150	161
Transfer to net assets held for sale	'	'
Other comprehensive income (loss), before reclassifications	-8	-61
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	'	'
Other Comprehensive Income (loss), net of tax	-8	-61
Accumulated other comprehensive income (loss), ending balance	142	100
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	'	'
Tax (expense) benefit on other comprehensive income (loss)	'	'

Assets_Liabilities_Held_for_Sa2

Assets & Liabilities Held for Sale and Discontinued Operations Income Statement Information (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Revenues	'	'
Net investment income	$41	$42
Net realized investment gains (losses)	1	5
Other revenues	'	1
Total revenues	42	48
Claims, Benefits and Expenses	'	'
Insurance claims and policyholders' benefits	31	33
Other operating expenses	1	1
Total claims, benefits and expenses	32	34
Income before income tax	10	14
Income tax (expense) benefit	-3	-5
Income from operations of discontinued operations, net of income tax	7	9
Impairment loss on sale, net of income tax benefit of $41 and -	-214	'
Income (loss) from discontinued operations	-207	9
Income tax benefit (expense) on impairment	$41	'

Assets_Liabilities_Held_for_Sa3

Assets & Liabilities Held for Sale and Discontinued Operations Balance Sheet Information (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets	'	'
Fixed maturity securities at fair value	$2,684	'
Equity securities at fair value	16	'
Other invested assets	1	'
Short term investments	36	'
Total investments	2,737	'
Cash	14	'
Reinsurance receivables	787	'
Other assets	55	'
Separate account business	148	'
Assets held for sale	3,741	'
Less: Impairment on sale	-255	'
Total assets held for sale	3,486	'
Liabilities	'	'
Insurance reserves	3,017	'
Other liabilities	85	'
Separate account business	148	'
Total liabilities held for sale	$3,250	'