CNA Financial (CNA) 10-K 23 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	CNA FINANCIAL CORP
Entity Central Index Key	21175
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding	270,015,043
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float	$1,084

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Revenues
Net earned premiums	$7,212		$7,271		$6,881
Net investment income	2,067		2,282		2,110
Net realized investment gains (losses):
Other-than-temporary impairment losses	-77		-74		-127
Portion of other-than-temporary impairments recognized in Other comprehensive income			-2		-23
Net other-than-temporary impairment losses recognized in earnings	-77		-76		-150
Other net realized investment gains (loss)	134		96		204
Net realized investment gains (losses)	57		20		54
Other revenues	356		359		319
Total revenues	9,692		9,932		9,364
Claims, Benefits and Expenses
Insurance claims and policyholders' benefits	5,591		5,806		5,729
Amortization of deferred acquisition costs	1,317		1,362		1,274
Other operating expenses	1,394		1,322		1,332
Interest	183		166		170
Total claims, benefits and expenses	8,485		8,656		8,505
Income (loss) from continuing operations before income tax	1,207		1,276		859
Income tax expense (benefit)	-319		-361		-239
Net income (loss) from continuing operations	888		915		620
(Loss) income from discontinued operations, net of income tax benefit (expense)	-197		22		8
Net income (loss)	$691	[1]	$937		$628
Basic Earnings (Loss) Per Share Attributable to CNA
Income (loss) from continuing operations	$3.29		$3.39		$2.30
(Loss) income from discontinued operations	($0.73)		$0.09		$0.03
Basic earnings (loss) per share	$2.56		$3.48		$2.33
Diluted Earnings (Loss) Per Share Attributable to CNA
Income (loss) from continuing operations	$3.28		$3.39		$2.30
(Loss) income from discontinued operations	($0.73)		$0.08		$0.03
Diluted earnings (loss) per share	$2.55		$3.47	[2]	$2.33
Dividends per share	$2		$0.80		$0.60
Weighted Average Outstanding Common Stock and Common Stock Equivalents
Basic	269.9		269.7		269.4
Diluted	270.6		270.2		269.8
[1]	Net income in the first quarter of 2014 includes the impairment loss on the sale of CAC.
[2]	Due to the averaging of shares, quarterly earnings per share do not add to the total for the full year.

Consolidated_Statements_of_Ope1

Consolidated Statements of Operations Parenthetical (Parentheticals) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Income tax benefit (expense) on discontinued operations	$34	($15)	($5)

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Other Comprehensive Income (Loss), Net of Tax, Changes In:
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Loss, Net of Tax, Portion Attributable to Parent, Available-for-sale Securities	$15		$6	$84
Net unrealized gains (losses) on other investments	267		-679	339
Net unrealized gains (losses) on investments	282		-673	423
Net unrealized losses on discontinued operations	-22
Foreign currency translation adjustment	-95		-11	40
Pension and postretirement benefits	-207		295	-112
Other comprehensive income (loss), net of tax	-42		-389	351
Net income (loss)	691	[1]	937	628
Total comprehensive income (loss)	$649		$548	$979
[1]	Net income in the first quarter of 2014 includes the impairment loss on the sale of CAC.

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets
Fixed maturity securities at fair value (amortized cost of $37,335 and $39,311)	$40,768	$41,233
Equity securities at fair value (cost of $210 and $179)	222	185
Limited partnership investments	2,937	2,720
Other invested assets	41	54
Mortgage loans	588	508
Short term investments	1,706	1,407
Total investments	46,262	46,107
Cash	190	195
Reinsurance receivables (less allowance for uncollectible receivables of $48 and $71)	4,694	6,017
Insurance receivables (less allowance for uncollectible receivables of $61 and $84)	1,936	1,979
Accrued investment income	405	443
Deferred acquisition costs	600	624
Deferred income taxes	191	220
Property and equipment at cost (less accumulated depreciation of $364 and $365)	295	304
Goodwill	152	155
Other assets	841	969
Separate account business		181
Total assets	55,566	57,194
Liabilities
Claim and claim adjustment expenses	23,271	24,089
Unearned premiums	3,592	3,718
Future policy benefits	9,490	10,471
Policyholders’ funds	27	116
Short term debt		549
Long term debt	2,559	2,011
Other liabilities (includes $153 and $197 due to Loews Corporation)	3,833	3,408
Separate account business		181
Total liabilities	42,772	44,543
Stockholders' Equity
Common stock ($2.50 par value; 500,000,000 shares authorized; 273,040,243 shares issued; 269,980,202 and 269,717,583 shares outstanding)	683	683
Additional paid-in capital	2,151	2,145
Retained earnings	9,645	9,495
Accumulated other comprehensive income (loss)	400	442
Treasury stock (3,060,041 and 3,322,660 shares), at cost	-84	-91
Notes receivable for the issuance of common stock	-1	-23
Total stockholders’ equity	12,794	12,651
Total liabilities and stockholders' equity	$55,566	$57,194

Consolidated_Balance_Sheet_Par

Consolidated Balance Sheet Parentheticals (Parentheticals) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Fixed maturities securities at amortized cost	$37,335	$39,311
Equity securities at cost	210	179
Allowance for uncollectible reinsurance receivables	48	71
Allowance for uncollectible insurance receivables	61	84
Accumulated depreciation on property and equipment	364	365
Due to Related Parties	$153	$197
Common stock, par value	$0	$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	269,980,202	269,717,583
Treasury stock, shares	3,060,041	3,322,660

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Cash Flows from Operating Activities
Net income (loss)	$691	[1]	$937	$628
Adjustments to reconcile net income (loss) to net cash flows provided (used) by operating activities:
Loss on sale of subsidiary	251
Deferred income tax expense (benefit)	3		77	147
Trading portfolio activity	16		-10	-23
Net realized investment (gains) losses	-60		-31	-63
Equity method investees	83		-323	-89
Amortization of investments	3		-24	-55
Depreciation and amortization	83		101	125
Changes in:
Receivables, net	731		44	49
Accrued investment income			-9	4
Deferred acquisition costs	44		2	-16
Insurance reserves	-363		-68	430
Other assets	-48		-27	144
Other liabilities	-48		525	-49
Other, net	54		10	18
Total adjustments	749		267	622
Net cash flows provided (used) by operating activities	1,440		1,204	1,250
Dispositions:
Fixed maturity securities - sales	4,914		6,869	6,123
Fixed maturity securities - maturities, calls and redemptions	3,983		3,271	3,699
Equity securities	31		103	86
Limited partnerships	167		108	165
Mortgage loans	57		22	7
Purchases:
Fixed maturity securities	-9,365		-11,197	-10,299
Equity securities	-67		-77	-54
Limited partnerships	-271		-223	-228
Mortgage loans	-137		-129	-174
Change in other investments	15		-22	22
Change in short term investments	-388		425	-7
Purchase of Hardy				-197
Purchases of property and equipment	-71		-91	-94
Proceeds from sale of subsidiaries	198
Other dispositions			32	1
Other, net	16		11	16
Net cash flows provided (used) by investing activities	-918		-898	-934
Cash Flows from Financing Activities
Dividends paid to common stockholders	-541		-216	-162
Proceeds from the issuance of debt	546
Repayment of debt	-549		-13	-70
Other, net	25		-35	-7
Net cash flows provided (used) by financing activities	-519		-264	-239
Effect of foreign exchange rate changes on cash	-8		-3	4
Net change in cash	-5		39	81
Cash, beginning of year	195		156	75
Cash, end of year	$190		$195	$156
[1]	Net income in the first quarter of 2014 includes the impairment loss on the sale of CAC.

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total		Common stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss) [Member]	Treasury stock [Member]	Notes receivable for the issuance of common stock [Member]
In Millions, unless otherwise specified
Balance at Dec. 31, 2011			$683	$2,141	$8,308	$480	($102)	($22)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	628				628
Other comprehensive income (loss), net of tax	351					351
Dividends paid to common stockholders					-162
Stock-based compensation				5			3
(Decrease) increase in notes receivable from the issuance of common stock								1
Balance at Dec. 31, 2012	12,314		683	2,146	8,774	831	-99	-21
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	937				937
Other comprehensive income (loss), net of tax	-389					-389
Dividends paid to common stockholders					-216
Stock-based compensation				-1			8
(Decrease) increase in notes receivable from the issuance of common stock								-2
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)	691	[1]			691
Other comprehensive income (loss), net of tax	-42					-42
Dividends paid to common stockholders					-541
Stock-based compensation				6			7
(Decrease) increase in notes receivable from the issuance of common stock								22
Balance at Dec. 31, 2014	$12,794		$683	$2,151	$9,645	$400	($84)	($1)
[1]	Net income in the first quarter of 2014 includes the impairment loss on the sale of CAC.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note A. Summary of Significant Accounting Policies
	Basis of Presentation
	The Consolidated Financial Statements 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 December 31, 2014.
	The accompanying Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). Intercompany amounts have been eliminated. The preparation of 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 Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from those estimates.
	Business
	The Company's core property and casualty insurance operations are reported in three business segments: Specialty, Commercial and International. The Company's non-core operations are managed in two segments: Life & Group Non-Core and Corporate & Other Non-Core. Each segment is managed separately due to differences in their markets and product mix.
	As a result of realigned management responsibilities, the Company revised its property and casualty segments in the fourth quarter of 2014. Results of CNA Europe and Canada that were previously included in the Specialty and Commercial segments are now included in the International segment. There was no change in the Company's Life & Group Non-Core and Corporate & Other Non-Core segments. Prior period segment disclosures have been conformed to the current year presentation. The new segment structure reflects the way management currently reviews results and makes business decisions.
	Core insurance products primarily include commercial property and casualty coverages, including surety. Non-core insurance products, which have been placed in run-off, primarily include long term care. CNA services include risk management, information services, warranty and claims administration. The Company's products and services are primarily marketed through independent agents, brokers and managing general underwriters to a wide variety of customers, including small, medium and large businesses, insurance companies, associations, professionals and other groups.
	Sale of Continental Assurance Company (CAC)
	On August 1, 2014, the Company completed the sale of the common stock of CAC. The business sold, which was previously reported within the Life & Group Non-Core segment, is reported as discontinued operations. The Company elected not to present the assets and liabilities as held for sale on the comparative Consolidated Balance Sheet and included CAC cash flow activity in the comparative Consolidated Statements of Cash Flow. Further information is provided in Note Q to the Consolidated Financial Statements.
	In connection with the sale of CAC, the Company entered into a 100% coinsurance agreement on a separate small block of annuity business outside of CAC. The coinsurance agreement required the transfer of assets with a book value equal to the ceded reserves on the inception date of the contract. Because a substantial portion of the assets supporting these liabilities are held in trust for the benefit of the original cedant, those assets were transferred on a funds withheld basis. Under this approach the Company maintains legal ownership of the assets, but the investment income and realized gains and losses on those assets inure to the reinsurer. As a result, the $34 million difference between market value and book value of the funds withheld assets at the coinsurance contract's inception was recognized as a loss in Other operating expenses. The funds withheld aspect of the agreement is considered an embedded derivative. The embedded derivative is separately accounted for at fair value and reported with the host contract in Other liabilities on the Company's Consolidated Balance Sheet. The Company recognizes Other operating expense equal to the Net investment income generated by these trust assets.
	Hardy Underwriting Bermuda Limited and its Subsidiaries (Hardy)
	On July 2, 2012, the Company completed the acquisition of all outstanding shares of Hardy, a specialized Lloyd's of London (Lloyd's) underwriter. Through Syndicate 382, Hardy underwrites primarily short-tail exposures in marine and aviation, non-marine property, specialty lines and property treaty reinsurance. The results of Hardy from the date of acquisition are included in the results of the Company's International segment.
	The purchase price for Hardy was $231 million. Acquisition related expenses of $4 million were incurred during the year ended December 31, 2012, including investment advisory, legal and other expenses, and were recorded in the Corporate & Other Non-Core segment.
	Insurance Operations
	Premiums: Insurance premiums on property and casualty insurance contracts are recognized in proportion to the underlying risk insured which principally are earned ratably over the duration of the policies. Premiums on long term care contracts are earned ratably over the policy year in which they are due. The reserve for unearned premiums represents the portion of premiums written relating to the unexpired terms of coverage.
	Insurance receivables include balances due currently or in the future, including amounts due from insureds related to losses under high deductible policies, and are presented at unpaid balances, net of an allowance for uncollectible receivables. Amounts are considered past due based on policy payment terms. That allowance is determined based on periodic evaluations of aged receivables, management's experience and current economic conditions. Insurance receivables and any related allowance are written off after collection efforts are exhausted or a negotiated settlement is reached.
	Property and casualty contracts that are retrospectively rated contain provisions that result in an adjustment to the initial policy premium depending on the contract provisions and loss experience of the insured during the experience period. For such contracts, the Company estimates the amount of ultimate premiums that the Company may earn upon completion of the experience period and recognizes either an asset or a liability for the difference between the initial policy premium and the estimated ultimate premium. The Company adjusts such estimated ultimate premium amounts during the course of the experience period based on actual results to date. The resulting adjustment is recorded as either a reduction of or an increase to the earned premiums for the period.
	Claim and claim adjustment expense reserves: Claim and claim adjustment expense reserves, except reserves for structured settlements not associated with asbestos and environmental pollution (A&EP), workers' compensation lifetime claims and accident and health claims, are not discounted and are based on 1) case basis estimates for losses reported on direct business, adjusted in the aggregate for ultimate loss expectations; 2) estimates of incurred but not reported (IBNR) losses; 3) estimates of losses on assumed reinsurance; 4) estimates of future expenses to be incurred in the settlement of claims; 5) estimates of salvage and subrogation recoveries and 6) estimates of amounts due from insureds related to losses under high deductible policies. Management considers current conditions and trends as well as past Company and industry experience in establishing these estimates. The effects of inflation, which can be significant, are implicitly considered in the reserving process and are part of the recorded reserve balance. Ceded claim and claim adjustment expense reserves are reported as a component of Reinsurance receivables on the Consolidated Balance Sheets.
	Claim and claim adjustment expense reserves are presented net of anticipated amounts due from insureds related to losses under deductible policies of $1.4 billion and $1.3 billion as of December 31, 2014 and 2013. A significant portion of these amounts are supported by collateral. The Company has an allowance for uncollectible deductible amounts, which is presented as a component of the allowance for doubtful accounts included in Insurance receivables on the Consolidated Balance Sheets.
	Structured settlements have been negotiated for certain property and casualty insurance claims. Structured settlements are agreements to provide fixed periodic payments to claimants. The Company's obligations for structured settlements not funded by annuities are included in claim and claim adjustment expense reserves and carried at present values determined using interest rates ranging from 5.5% to 8.0% at December 31, 2014 and 7.1% to 9.7% at December 31, 2013. At December 31, 2014 and 2013, the discounted reserves for unfunded structured settlements were $582 million and $580 million, net of discount of $924 million and $969 million.
	Workers' compensation lifetime claim reserves are calculated using mortality assumptions determined through statutory regulation and economic factors. Accident and health claim reserves are calculated using mortality and morbidity assumptions based on Company and industry experience. Workers' compensation lifetime claim reserves and accident and health claim reserves are discounted at interest rates ranging from 3.5% to 6.8% at December 31, 2014 and 3.0% to 6.8% at December 31, 2013. At December 31, 2014 and 2013, such discounted reserves totaled $2.5 billion and $2.4 billion, net of discount of $654 million and $617 million.
	Future policy benefits reserves: Reserves for long term care policies and payout annuity contracts are computed using the net level premium method, which incorporates actuarial assumptions as to morbidity, persistency, discount rate and expenses. Expense assumptions primarily relate to claim adjudication. Actuarial assumptions generally vary by plan, age at issue and policy duration. The initial assumptions are determined at issuance, include a margin for adverse deviation and are locked in throughout the life of the contract unless a premium deficiency develops. If a premium deficiency emerges, the assumptions are unlocked and deferred acquisition costs, if any, and the future policy benefit reserves are adjusted. Interest rates for long term care products range from 4.5% to 7.9% at December 31, 2014 and 2013. Interest rates for payout annuity contracts ranged from 5.0% to 8.7% at December 31, 2013.
	Policyholders' funds reserves: Policyholders' funds reserves on the Consolidated Balance Sheet as of December 31, 2013 primarily included reserves for investment contracts without life contingencies. For these contracts, policyholder liabilities are generally equal to the accumulated policy account values, which consist of an accumulation of deposit payments plus credited interest, less withdrawals and amounts assessed through the end of the period.
	Guaranty fund and other insurance-related assessments: Liabilities for guaranty fund and other insurance-related assessments are accrued when an assessment is probable, when it can be reasonably estimated and when the event obligating the entity to pay an imposed or probable assessment has occurred. Liabilities for guaranty funds and other insurance-related assessments are not discounted and are included as part of Other liabilities on the Consolidated Balance Sheets. As of December 31, 2014 and 2013, the liability balances were $131 million and $143 million.
	Reinsurance: Reinsurance accounting allows for contractual cash flows to be reflected as premiums and losses. To qualify for reinsurance accounting, reinsurance agreements must include risk transfer. To meet risk transfer requirements, a reinsurance contract must include both insurance risk, consisting of underwriting and timing risk, and a reasonable possibility of a significant loss for the assuming entity.
	Reinsurance receivables related to paid losses are presented at unpaid balances. Reinsurance receivables related to unpaid losses are estimated in a manner consistent with claim and claim adjustment expense reserves or future policy benefits reserves. Reinsurance receivables are reported net of an allowance for uncollectible amounts on the Consolidated Balance Sheets. The cost of reinsurance is primarily accounted for over the life of the underlying reinsured policies using assumptions consistent with those used to account for the underlying policies or over the reinsurance contract period. The ceding of insurance does not discharge the primary liability of the Company.
	The Company has established an allowance for uncollectible reinsurance receivables which relates to both amounts already billed on ceded paid losses as well as ceded reserves that will be billed when losses are paid in the future. The allowance for uncollectible reinsurance receivables is estimated on the basis of periodic evaluations of balances due from reinsurers, reinsurer solvency, management's experience and current economic conditions. Reinsurer financial strength ratings are updated and reviewed on an annual basis or sooner if the Company becomes aware of significant changes related to a reinsurer. Because billed receivables generally approximate 5% or less of total reinsurance receivables, the age of the reinsurance receivables related to paid losses is not a significant input into the allowance analysis. Changes in the allowance for uncollectible reinsurance receivables are presented as a component of Insurance claims and policyholders' benefits on the Consolidated Statements of Operations.
	Amounts are considered past due based on the reinsurance contract terms. Reinsurance receivables related to paid losses and any related allowance are written off after collection efforts have been exhausted or a negotiated settlement is reached with the reinsurer. Reinsurance receivables related to paid losses from insolvent insurers are written off when the settlement due from the estate can be reasonably estimated. At the time reinsurance receivables related to paid losses are written off, any required adjustment to reinsurance receivables related to unpaid losses is recorded as a component of Insurance claims and policyholders' benefits on the Consolidated Statements of Operations.
	Reinsurance contracts that do not effectively transfer the economic risk of loss on the underlying policies are recorded using the deposit method of accounting, which requires that premium paid or received by the ceding company or assuming company be accounted for as a deposit asset or liability. The Company had $3 million recorded as deposit assets at December 31, 2014 and 2013, and $9 million and $130 million recorded as deposit liabilities at December 31, 2014 and 2013. Income on reinsurance contracts accounted for under the deposit method is recognized using an effective yield based on the anticipated timing of payments and the remaining life of the contract. When the anticipated timing of payments changes, the effective yield is recalculated to reflect actual payments to date and the estimated timing of future payments. The deposit asset or liability is adjusted to the amount that would have existed had the new effective yield been applied since the inception of the contract.
	A loss portfolio transfer is a retroactive reinsurance contract. If the cumulative claim and allocated claim adjustment expenses ceded under a loss portfolio transfer exceed the consideration paid, the resulting gain from such excess is deferred and amortized into earnings in future periods in proportion to actual recoveries under the loss portfolio transfer. In the period in which an excess arises, a portion of the deferred gain is cumulatively recognized in earnings as if the revised estimate was available at the inception date of the loss portfolio transfer.
	Deferred acquisition costs: Acquisition costs include commissions, premium taxes and certain underwriting and policy issuance costs which are incremental direct costs of successful contract acquisitions. Deferred acquisition costs related to long term care contracts issued prior to January 1, 2004 include costs which vary with and are primarily related to the acquisition of business.
	Acquisition costs related to property and casualty business are deferred and amortized ratably over the period the related premiums are earned.
	Deferred acquisition costs related to long term care contracts are amortized over the premium-paying period of the related policies using assumptions consistent with those used for computing future policy benefit reserves for such contracts. Assumptions are made at the date of policy issuance or acquisition and are consistently applied during the lives of the contracts. Deviations from estimated experience are included in results of operations when they occur. For these contracts, the amortization period is typically the estimated life of the policy. At December 31, 2014 and 2013, Deferred acquisition costs were presented net of Shadow Adjustments, as defined later in this note, of $314 million and $342 million.
	The Company evaluates deferred acquisition costs for recoverability. Anticipated investment income is considered in the determination of the recoverability of deferred acquisition costs. Adjustments, if necessary, are recorded in current period results of operations.
	Deferred acquisition costs are presented net of ceding commissions and other ceded acquisition costs. Unamortized deferred acquisition costs relating to contracts that have been substantially changed by a modification in benefits, features, rights or coverages that were not anticipated in the original contract are not deferred and are included as a charge to operations in the period during which the contract modification occurred.
	Investments in life settlement contracts and related revenue recognition: Prior to 2002, the Company purchased investments in life settlement contracts. A life settlement contract is a contract between the owner of a life insurance policy (the policy owner) and a third-party investor (investor). Under a life settlement contract, the Company obtains the ownership and beneficiary rights of an underlying life insurance policy.
	The Company accounts for its investments in life settlement contracts using the fair value method. Under the fair value method, each life settlement contract is carried at its fair value at the end of each reporting period. The change in fair value, life insurance proceeds received and periodic maintenance costs, such as premiums, necessary to keep the underlying policy in force, are recorded in Other revenues on the Consolidated Statements of Operations.
	The fair value of the Company's investments in life settlement contracts were $82 million and $88 million at December 31, 2014 and 2013, and are included in Other assets on the Consolidated Balance Sheets. The cash receipts and payments related to life settlement contracts are included in Cash flows from operating activities on the Consolidated Statements of Cash Flows.
	The following table details the values for life settlement contracts. The determination of fair value is discussed in Note D to the Consolidated Financial Statements.
	December 31, 2014	Number of Life Settlement Contracts	Fair Value of Life Settlement Contracts		Face Amount of Life Insurance Policies
			(In millions)		(In millions)
	Estimated maturity during:
	2015	60	$	11	$	37
	2016	60	10		33
	2017	50	9		30
	2018	50	7		26
	2019	50	6		26
	Thereafter	318	39		187
	Total	588	$	82	$	339
	The Company uses an actuarial model to estimate the aggregate face amount of life insurance that is expected to mature in each future year and the corresponding fair value. This model projects the likelihood of the insured's death for each inforce policy based upon the Company's estimated mortality rates, which may vary due to the relatively small size of the portfolio of life settlement contracts. The number of life settlement contracts presented in the table above is based upon the average face amount of inforce policies estimated to mature in each future year.
	The increase (decrease) in fair value recognized for the years ended December 31, 2014, 2013 and 2012 on contracts still held at each respective period-end was $8 million, $(2) million and $11 million. The gains recognized during the years ended December 31, 2014, 2013 and 2012 on contracts that settled were $25 million, $15 million and $42 million.
	Separate Account Business: Separate account assets and liabilities on the Consolidated Balance Sheet as of December 31, 2013 represented contract holder funds related to investment and annuity products for which the policyholder assumes substantially all the risk and reward. The assets were segregated into accounts with specific underlying investment objectives and are legally segregated from the Company. All assets of the separate account business were carried at fair value with an equal amount recorded for separate account liabilities.
	Investments
	The Company classifies its fixed maturity securities and its equity securities as either available-for-sale or trading, and as such, they are carried at fair value. Changes in fair value of trading securities are reported within Net investment income on the Consolidated Statements of Operations. Changes in fair value related to available-for-sale securities are reported as a component of Other comprehensive income. The cost of fixed maturity securities classified as available-for-sale is adjusted for amortization of premiums and accretion of discounts to maturity, which are included in Net investment income on the Consolidated Statements of Operations. Losses may be recognized within Net realized investment gains (losses) on the Consolidated Statements of Operations when a decline in value is determined by the Company to be other-than-temporary.
	To the extent that unrealized gains on fixed income securities supporting long term care products and payout annuity contracts would result in a premium deficiency if those gains were 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 (Shadow Adjustments). Shadow Adjustments, net of tax, increased $756 million and decreased $979 million for the years ended December 31, 2014 and 2013. At December 31, 2014 and 2013, net unrealized gains on investments included in Accumulated other comprehensive income (AOCI) were correspondingly reduced by $1,288 million and $532 million.
	For asset-backed securities included in fixed maturity securities, the Company recognizes income using an effective yield based on anticipated prepayments and the estimated economic life of the securities. When estimates of prepayments change, the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The amortized cost of high credit quality fixed rate securities is adjusted to the amount that would have existed had the new effective yield been applied since the acquisition of the securities. Such adjustments are reflected in Net investment income on the Consolidated Statements of Operations. Interest income on lower rated and variable rate securities is determined using the prospective yield method.
	The Company's carrying value of investments in limited partnerships is its share of the net asset value of each partnership, as determined by the General Partner. Certain partnerships for which results are not available on a timely basis are reported on a lag, primarily three months or less. Changes in net asset values are accounted for under the equity method and recorded within Net investment income on the Consolidated Statements of Operations.
	Mortgage loans are commercial in nature, are carried at unpaid principal balance, net of unamortized fees and any valuation allowance, and are recorded once funded. Mortgage loans are considered to be impaired loans when it is probable that contractual principal and interest payments will not be collected. A valuation allowance is established for impaired loans to the extent that the present value of expected future cash flows discounted at the loan's original effective interest rate is less than the carrying value of the loan. Interest income from mortgage loans is recognized on an accrual basis using the effective yield method. Accrual of income is generally suspended for mortgage loans that are impaired and collection of principal and interest payments is unlikely. Mortgage loans are considered past due when full principal or interest payments have not been received according to contractual terms.
	Other invested assets are carried at fair value and include overseas deposits and certain derivative securities. Overseas deposits are primarily short-term government securities, agency securities and corporate bonds held in trusts that are managed by Lloyd's. These funds are required of Lloyd's syndicates to protect policyholders in overseas markets and may be denominated in local currency.
	Short term investments are carried at fair value, with the exception of cash accounts earning interest, which are carried at cost and approximate fair value. Changes in fair value are reported as a component of Other comprehensive income.
	Purchases and sales of all securities are recorded on the trade date, except for private placement debt securities, including bank loan participations, which are recorded once funded. Realized investment gains and losses are determined on the basis of the cost or amortized cost of the specific securities sold.
	In the normal course of investing activities, the Company enters into relationships with variable interest entities (VIEs), primarily as a passive investor in certain limited partnerships and asset-backed securities issued by third-party VIEs. The Company is not the primary beneficiary of these VIEs, and therefore does not consolidate them. The Company determines whether it is the primary beneficiary of a VIE based on a qualitative assessment of the entity’s purpose, the nature of its operations, its capital structure, its contractual terms and the Company’s relative exposure to the related risks of the VIE. The Company’s maximum exposure to loss with respect to these investments is limited to the investment carrying values included in the Company’s Consolidated Balance Sheets and any unfunded commitments.
	A security is impaired if the fair value of the security is less than its cost adjusted for accretion, amortization and previously recorded other-than-temporary impairment (OTTI) losses, otherwise defined as an unrealized loss. When a security is impaired, the impairment is evaluated to determine whether it is temporary or other-than-temporary.
Significant judgment is required in the determination of whether an OTTI loss has occurred for a security. The Company follows a consistent and systematic process for determining and recording an OTTI loss. The Company has established a committee responsible for the OTTI process. This committee, referred to as the Impairment Committee, is made up of three officers appointed by the Company’s Chief Financial Officer. The Impairment Committee is responsible for evaluating all securities in an unrealized loss position on at least a quarterly basis.
The Impairment Committee’s assessment of whether an OTTI loss has occurred incorporates both quantitative and qualitative information. Fixed maturity securities that the Company intends to sell, or it more likely than not will be required to sell before recovery of amortized cost, are considered to be other-than-temporarily impaired and the entire difference between the amortized cost basis and fair value of the security is recognized as an OTTI loss in earnings. The remaining fixed maturity securities in an unrealized loss position are evaluated to determine if a credit loss exists. The factors considered by the Impairment Committee include (a) the financial condition and near term prospects of the issuer, (b) whether the debtor is current on interest and principal payments, (c) credit ratings of the securities and (d) general market conditions and industry or sector specific outlook. The Company also considers results and analysis of cash flow modeling for asset-backed securities, and when appropriate, other fixed maturity securities. The focus of the analysis for asset-backed securities is on assessing the sufficiency and quality of underlying collateral and timing of cash flows based on scenario tests. If the present value of the modeled expected cash flows equals or exceeds the amortized cost of a security, no credit loss is judged to exist and the asset-backed security is deemed to be temporarily impaired. If the present value of the expected cash flows is less than amortized cost, the security is judged to be other-than-temporarily impaired for credit reasons and that shortfall, referred to as the credit component, is recognized as an OTTI loss in earnings. The difference between the adjusted amortized cost basis and fair value, referred to as the non-credit component, is recognized as OTTI in Other comprehensive income. In subsequent reporting periods, a change in intent to sell or further credit impairment on a security whose fair value has not deteriorated will cause the non-credit component originally recorded as OTTI in Other comprehensive income to be recognized as an OTTI loss in earnings.
The Company performs the discounted cash flow analysis using stressed scenarios to determine future expectations regarding recoverability. Significant assumptions enter into these cash flow projections including delinquency rates, probable risk of default, loss severity upon a default, over collateralization and interest coverage triggers and credit support from lower level tranches.
The Company applies the same impairment model as described above for the majority of non-redeemable preferred stock securities on the basis that these securities possess characteristics similar to debt securities and that the issuers maintain their ability to pay dividends. For all other equity securities, in determining whether the security is other-than-temporarily impaired, the Impairment Committee considers a number of factors including, but not limited to: (a) the length of time and the extent to which the fair value has been less than amortized cost, (b) the financial condition and near term prospects of the issuer, (c) the intent and ability of the Company to retain its investment for a period of time sufficient to allow for an anticipated recovery in value and (d) general market conditions and industry or sector specific outlook.
Income Taxes
The Company and its eligible subsidiaries (CNA Tax Group) are included in the consolidated federal income tax return of Loews and its eligible subsidiaries. The Company accounts for income taxes under the asset and liability method. Under the asset and liability method, deferred income taxes are recognized for temporary differences between the financial statement and tax return bases of assets and liabilities, based on enacted tax rates and other provisions of the tax law. The effect of a change in tax laws or rates on deferred tax assets and liabilities is recognized in income in the period in which such change is enacted. Future tax benefits are recognized to the extent that realization of such benefits is more likely than not, and a valuation allowance is established for any portion of a deferred tax asset that management believes will not be realized.
Pension and Postretirement Benefits
The Company recognizes the overfunded or underfunded status of its defined benefit plans in Other assets or Other liabilities on the Consolidated Balance Sheets. Changes in funded status related to prior service costs and credits and actuarial gains and losses are recognized in the year in which the changes occur through Other comprehensive income. Annual service cost, interest cost, expected return on plan assets, amortization of prior service costs and credits and amortization of actuarial gains and losses are recognized in the Consolidated Statements of Operations. The vested benefit obligation for the CNA Retirement Plan is determined based on the employees’ expected date of separation or retirement.
Stock-Based Compensation
The Company records compensation expense using the fair value method for all awards it grants, modifies or cancels primarily on a straight-line basis over the requisite service period, generally three to four years.
Foreign Currency
Foreign currency translation gains and losses are reflected in Stockholders' equity as a component of AOCI. The Company's foreign subsidiaries' balance sheet accounts are translated at the exchange rates in effect at each reporting date and income statement accounts are either translated at the exchange rate on the date of the transaction or at the average exchange rates. Foreign currency transaction gains (losses) of $(25) million, $2 million and $12 million were included in determining net income (loss) for the years ended December 31, 2014, 2013 and 2012.
Property and Equipment
Property and equipment are carried at cost less accumulated depreciation. Depreciation is based on the estimated useful lives of the various classes of property and equipment and is determined principally on the straight-line method. Furniture and fixtures are depreciated over seven years. Office equipment is depreciated over five years. The estimated lives for data processing equipment and software range from three to five years. Leasehold improvements are depreciated over the corresponding lease terms not to exceed the underlying asset life. The Company's owned buildings, and related capital improvements, are depreciated over periods not to exceed fifty years.
Goodwill
Goodwill represents the excess of purchase price over the fair value of the net assets of acquired entities and businesses. Goodwill in the International segment may change from period to period as a result of foreign currency translation.
Goodwill is tested for impairment annually or when certain triggering events require such tests. As a result of reviews completed for the year ended December 31, 2014, the Company determined that the estimated fair value of the reporting units were in excess of their carrying value including Goodwill. Changes in future periods in assumptions about the level of economic capital, business growth, earnings projections or the weighted average cost of capital could result in a goodwill impairment.
Other Intangible Assets
Other intangible assets are reported within Other assets. Finite-lived intangible assets are amortized over their estimated useful lives. Indefinite-lived other intangible assets are tested for impairment annually or when certain triggering events require such tests.
Earnings (Loss) Per Share Data
Earnings (loss) per share is based on 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 years ended December 31, 2014, 2013 and 2012, approximately 675 thousand, 552 thousand and 417 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 170 thousand, 111 thousand and 730 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.
Supplementary Cash Flow Information
Cash payments made for interest were $179 million, $164 million and $170 million for the years ended December 31, 2014, 2013 and 2012. Cash payments made for income taxes were $313 million and $129 million for the years ended December 31, 2014 and 2013. Cash refunds received for income taxes were $29 million for the year ended December 31, 2012.

Investments

Investments	12 Months Ended
	Dec. 31, 2014
Investments [Abstract]
Investments	Note B. Investments
	The significant components of net investment income are presented in the following table.
	Net Investment Income
	Years ended December 31
	(In millions)	2014			2013			2012
	Fixed maturity securities	$	1,803		$	1,827		$	1,846
	Short term investments	3			3			5
	Limited partnership investments	263			451			251
	Equity securities	12			12			12
	Mortgage loans	31			23			17
	Trading portfolio	10			17			24
	Other	3			2			7
	Gross investment income	2,125			2,335			2,162
	Investment expense	(58		)	(53		)	(52		)
	Net investment income	$	2,067		$	2,282		$	2,110
	As of December 31, 2014 and 2013, the Company held no non-income producing fixed maturity securities. As of December 31, 2014 and 2013, no investments in a single issuer exceeded 10% of stockholders' equity, other than investments in securities issued by the U.S. Treasury and obligations of government-sponsored enterprises.
	Net realized investment gains (losses) are presented in the following table.
	Net Realized Investment Gains (Losses)
	Years ended December 31
	(In millions)	2014			2013			2012
	Net realized investment gains (losses):
	Fixed maturity securities:
	Gross realized gains	$	170		$	185		$	222
	Gross realized losses	(129		)	(144		)	(145		)
	Net realized investment gains (losses) on fixed maturity securities	41			41			77
	Equity securities:
	Gross realized gains	8			13			19
	Gross realized losses	(7		)	(35		)	(42		)
	Net realized investment gains (losses) on equity securities	1			(22		)	(23		)
	Derivatives	(1		)	(9		)	(2		)
	Short term investments and other	16			10			2
	Net realized investment gains (losses)	$	57		$	20		$	54
	Net change in unrealized gains on investments is presented in the following table.
	Net Change in Unrealized Gains
	Years ended December 31
	(In millions)	2014			2013			2012
	Net change in unrealized gains on investments:
	Fixed maturity securities	$	1,511		$	(2,541	)	$	1,871
	Equity securities	6			(15		)	5
	Other	—			—			(1		)
	Total net change in unrealized gains on investments	$	1,517		$	(2,556	)	$	1,875
	The components of OTTI losses recognized in earnings by asset type are summarized in the following table.
	Years ended December 31
	(In millions)	2014			2013			2012
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	18		$	20		$	25
	States, municipalities and political subdivisions	46			—			34
	Asset-backed:
	Residential mortgage-backed	5			19			48
	Other asset-backed	1			2			—
	Total asset-backed	6			21			48
	U.S. Treasury and obligations of government-sponsored enterprises	—			—			1
	Total fixed maturity securities available-for-sale	70			41			108
	Equity securities available-for-sale:
	Common stock	7			8			6
	Preferred stock	—			26			36
	Total equity securities available-for-sale	7			34			42
	Short term investments	—			1			—
	OTTI losses recognized in earnings	$	77		$	76		$	150
	The following tables provide a summary of fixed maturity and equity securities.
	Summary of Fixed Maturity and Equity Securities
	December 31, 2014	Cost or			Gross			Gross			Estimated		Unrealized
		Amortized			Unrealized			Unrealized			Fair		OTTI
	(In millions)	Cost			Gains			Losses			Value		Losses (Gains)
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	17,210		$	1,721		$	61		$	18,870	$	—
States, municipalities and political subdivisions	11,285			1,463			8			12,740		—
Asset-backed:
Residential mortgage-backed	5,028			218			13			5,233		(53		)
Commercial mortgage-backed	2,056			93			5			2,144		(2		)
Other asset-backed	1,234			11			10			1,235		—
Total asset-backed	8,318			322			28			8,612		(55		)
U.S. Treasury and obligations of government-sponsored enterprises	26			5			—			31		—
Foreign government	438			16			—			454		—
Redeemable preferred stock	39			3			—			42		—
Total fixed maturity securities available-for-sale	37,316			3,530			97			40,749		$	(55	)
Total fixed maturity securities trading	19									19
Equity securities available-for-sale:
Common stock	38			9			—			47
Preferred stock	172			5			2			175
Total equity securities available-for-sale	210			14			2			222
Total	$	37,545		$	3,544		$	99		$	40,990
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 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
December 31, 2014	Estimated			Gross			Estimated			Gross		Estimated			Gross
	Fair Value			Unrealized			Fair Value			Unrealized		Fair Value			Unrealized
(In millions)				Losses						Losses					Losses
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	1,330		$	46		$	277		$	15	$	1,607		$	61
States, municipalities and political subdivisions	335			5			127			3		462			8
Asset-backed:
Residential mortgage-backed	293			5			189			8		482			13
Commercial mortgage-backed	264			2			99			3		363			5
Other asset-backed	607			10			7			—		614			10
Total asset-backed	1,164			17			295			11		1,459			28
U.S. Treasury and obligations of government-sponsored enterprises	3			—			4			—		7			—
Foreign government	3			—			3			—		6			—
Redeemable preferred stock	3			—			—			—		3			—
Total fixed maturity securities available-for-sale	2,838			68			706			29		3,544			97
Equity securities available-for-sale:
Preferred stock	17			2			1			—		18			2
Total	$	2,855		$	70		$	707		$	29	$	3,562		$	99
	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 December 31, 2014 Securities in a Gross Unrealized Loss Position table above, are not indicative of the ultimate collectibility of the current amortized cost of the securities, but rather are primarily attributable to changes in interest rates and credit spreads, market illiquidity and other factors. The Company has no current intent to sell securities with unrealized losses, nor is it more likely than not that it will be required to sell prior to recovery of amortized cost; accordingly, the Company has determined that there are no additional OTTI losses to be recorded at December 31, 2014.
The following table summarizes the activity for the years ended December 31, 2014, 2013 and 2012 related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held at December 31, 2014, 2013 and 2012 for which a portion of an OTTI loss was recognized in Other comprehensive income.
Years ended December 31
(In millions)	2014			2013			2012
Beginning balance of credit losses on fixed maturity securities	$	74		$	95		$	92
Additional credit losses for securities for which an OTTI loss was previously recognized	—			2			23
Credit losses for securities for which an OTTI loss was not previously recognized	—			—			2
Reductions for securities sold during the period	(9		)	(23		)	(14		)
Reductions for securities the Company intends to sell or more likely than not will be required to sell	(3		)	—			(8		)
Ending balance of credit losses on fixed maturity securities	$	62		$	74		$	95
Contractual Maturity
The following table summarizes available-for-sale fixed maturity securities by contractual maturity. 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
31-Dec	2014						2013
(In millions)	Cost or			Estimated			Cost or			Estimated
	Amortized			Fair			Amortized			Fair
	Cost			Value			Cost			Value
Due in one year or less	$	2,479		$	2,511		$	2,420		$	2,455
Due after one year through five years	9,054			9,605			9,496			10,068
Due after five years through ten years	12,055			12,584			11,667			11,954
Due after ten years	13,728			16,049			15,692			16,720
Total	$	37,316		$	40,749		$	39,275		$	41,197
Limited Partnerships
The carrying value of limited partnerships as of December 31, 2014 and 2013 was $2,937 million and $2,720 million, which includes undistributed earnings of $1,040 million and $969 million. Limited partnerships comprising 65% of the total carrying value are reported on a current basis through December 31, 2014 with no reporting lag, 16% are reported on a one month lag and the remainder are reported on more than a one month lag. As of December 31, 2014 and 2013, the Company had 86 and 87 active limited partnership investments. The number of limited partnerships held and the strategies employed provide diversification to the limited partnership portfolio and the overall invested asset portfolio.
Of the limited partnerships held, 73% and 74% at December 31, 2014 and 2013 employ hedge fund strategies that generate returns through investing in marketable securities in the public fixed income and equity markets. Limited partnerships representing 23% and 22% at December 31, 2014 and 2013 were invested in private debt and equity, and the remaining limited partnerships were primarily invested in real estate strategies. Hedge fund strategies include both long and short positions in fixed income, equity and derivative instruments. These hedge fund strategies may seek to generate gains from mispriced or undervalued securities, price differentials between securities, distressed investments, sector rotation or various arbitrage disciplines. Within hedge fund strategies, approximately 56% were equity related, 27% pursued a multi-strategy approach, 14% were focused on distressed investments and 3% were fixed income related at December 31, 2014.
The ten largest limited partnership positions held totaled $1,492 million and $1,471 million as of December 31, 2014 and 2013. Based on the most recent information available regarding the Company’s percentage ownership of the individual limited partnerships, the carrying value reflected on the Consolidated Balance Sheets represents approximately 4% of the aggregate partnership equity at December 31, 2014 and 2013, and the related income reflected on the Consolidated Statements of Operations represents approximately 4%, 4% and 3% of the changes in total partnership equity for the years ended December 31, 2014, 2013 and 2012.
While the Company generally does not invest in highly leveraged partnerships, there are risks which may result in losses due to short-selling, derivatives or other speculative investment practices. The use of leverage increases volatility generated by the underlying investment strategies.
The Company’s limited partnership investments contain withdrawal provisions that generally limit liquidity for a period of thirty days up to one year and in some cases do not permit withdrawals until the termination of the partnership. Typically, withdrawals require advance written notice of up to 90 days.
Commercial Mortgage Loans
Risks related to the recoverability of loan balances include declines in the estimated cash flows from underlying property leases, fair value of collateral and creditworthiness of tenants of credit tenant loan properties, where lease payments directly service the loan. The Company evaluates loans for impairment on a specific loan basis and identifies loans for evaluation of impairment based on the collection experience of each loan and other credit quality indicators such as debt service coverage ratio and the creditworthiness of the borrower or tenants of credit tenant loan properties. As of December 31, 2014 and 2013, there were no loans past due or in non-accrual status, and no valuation allowance was recorded.
Investment Commitments
As of December 31, 2014, the Company had committed approximately $327 million to future capital calls from various third-party limited partnership investments in exchange for an ownership interest in the related partnerships.
As of December 31, 2014, the Company had a mortgage loan commitment of $8 million representing a signed loan application 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 December 31, 2014, the Company had commitments to purchase or fund additional amounts of $75 million and sell $97 million under the terms of such securities.
Investments on Deposit
Securities with carrying values of approximately $3.0 billion and $3.3 billion were deposited by the Company’s insurance subsidiaries under requirements of regulatory authorities and others as of December 31, 2014 and 2013.
Cash and securities with carrying values of approximately $361 million and $353 million were deposited with financial institutions as collateral for letters of credit as of December 31, 2014 and 2013. In addition, cash and securities were deposited in trusts with financial institutions to secure reinsurance and other obligations with various third parties. The carrying values of these deposits were approximately $302 million and $294 million as of December 31, 2014 and 2013.

Derivative_Financial_Instrumen

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2014
Summary of Derivative Instruments [Abstract]
Derivative Financial Instruments	Note C. Derivative Financial Instruments
	The Company may use derivatives in the normal course of business, primarily in an attempt to reduce its exposure to market risk (principally interest rate risk, credit risk, equity price risk and foreign currency risk) stemming from various assets and liabilities. The Company's principal objective under such strategies is to achieve the desired reduction in economic risk, even if the position does not receive hedge accounting treatment.
	The Company may enter into interest rate swaps, futures and commitments to purchase securities to manage interest rate risk. The Company may use foreign currency forward contracts to manage foreign currency risk.
	In addition to the derivatives used for risk management purposes described above, the Company may also use derivatives for purposes of income enhancement. Income enhancement transactions are limited in scope and primarily involve the sale of covered options in which the Company receives a premium in exchange for selling a call or put option.
	Credit exposure associated with non-performance by the counterparties to derivative instruments is generally limited to the uncollateralized fair value of the asset related to the instruments recognized on the Consolidated Balance Sheets. The Company generally requires that all over-the-counter derivative contracts be governed by an International Swaps and Derivatives Association Master Agreement, and exchanges collateral under the terms of these agreements with its derivative investment counterparties depending on the amount of the exposure and the credit rating of the counterparty. Gross estimated fair values of derivative positions are presented in Other invested assets and Other liabilities on the Consolidated Balance Sheet. The Company does not offset derivative positions against the fair value of collateral provided or positions subject to netting arrangements. There would be no significant difference in the balance included in such accounts if the estimated fair values were presented net for the periods ended December 31, 2014 and 2013. There was no cash collateral provided by the Company at December 31, 2014 or 2013. There was no cash collateral received from counterparties held at December 31, 2014 or 2013.
	A summary of the aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments reported as Other invested assets or Other liabilities on the Consolidated Balance Sheets follows. 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
	December 31, 2014	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Currency forwards	$	9	$	—	$	—
	Equity warrants	5		—		—
	Embedded derivative on funds withheld liability	184		—		(3		)
	Total			$	—	$	(3	)
	December 31, 2013	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Equity warrants	$	5	$	—	$	—
	For further discussion of the embedded derivative on funds withheld liability, see Note A to the Consolidated Financial Statements.

Fair_Value

Fair Value	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value	Note D. Fair Value
	Fair value is the price that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The following fair value hierarchy is used in selecting inputs, with the highest priority given to Level 1, as these are the most transparent or reliable.
	Level 1 - Quoted prices for identical instruments in active markets.
	Level 2 - Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs are observable in active markets.
	Level 3 - Valuations derived from valuation techniques in which one or more significant inputs are not observable.
	Prices may fall within Level 1, 2 or 3 depending upon the methodologies and inputs used to estimate fair value for each specific security. In general the Company seeks to price securities using third-party pricing services. Securities not priced by pricing services are submitted to independent brokers for valuation and, if those are not available, internally developed pricing models are used to value assets using methodologies and inputs the Company believes market participants would use to value the assets. Prices obtained from third-party pricing services or brokers are not adjusted by the Company.
	The Company performs control procedures over information obtained from pricing services and brokers to ensure prices received represent a reasonable estimate of fair value and to confirm representations regarding whether inputs are observable or unobservable. Procedures include i) the review of pricing service or broker pricing methodologies, ii) back-testing, where past fair value estimates are compared to actual transactions executed in the market on similar dates, iii) exception reporting, where changes in price, period-over-period, are reviewed and challenged with the pricing service or broker based on exception criteria, iv) deep dives, where the Company performs an independent analysis of the inputs and assumptions used to price individual securities and v) pricing validation, where prices received are compared to prices independently estimated by the Company.
	Assets and Liabilities Measured at Fair Value
	Assets and liabilities measured at fair value on a recurring basis are summarized below.
	December 31, 2014									Total
										Assets/ (Liabilities)
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	32	$	18,695		$	162		$	18,889
	States, municipalities and political subdivisions	—		12,646			94			12,740
	Asset-backed:
	Residential mortgage-backed	—		5,044			189			5,233
	Commercial mortgage-backed	—		2,061			83			2,144
	Other asset-backed	—		580			655			1,235
	Total asset-backed	—		7,685			927			8,612
	U.S. Treasury and obligations of government-sponsored enterprises	28		3			—			31
	Foreign government	41		413			—			454
	Redeemable preferred stock	30		12			—			42
	Total fixed maturity securities	131		39,454			1,183			40,768
	Equity securities	145		61			16			222
	Other invested assets	—		41			—			41
	Short term investments	681		963			—			1,644
	Life settlement contracts, included in Other assets	—		—			82			82
	Total assets	$	957	$	40,519		$	1,281		$	42,757
	Liabilities
	Other liabilities	$	—	$	(3	)	$	—		$	(3	)
	Total liabilities	$	—	$	(3	)	$	—		$	(3	)
	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 years ended December 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 December 31, 2014 recognized in net income (loss)*
	(In millions)	January 1,																	Level 3		of Level 3			December 31,
		2014																						2014
	Fixed maturity securities:
	Corporate and other bonds	$	204	$	2		$	(1	)	$	33		$	(23	)	$	(16	)	$	18	$	(55	)	$	162	$	—
	States, municipalities and political subdivisions	71		1			4			14			(10		)	—			14		—			94		—
	Asset-backed:
	Residential mortgage-backed	331		(21		)	61			94			(174		)	(72		)	32		(62		)	189		—
Commercial mortgage-backed	151		7			(6		)	28			(60		)	(29		)	43		(51		)	83		—
Other asset-backed	446		2			(6		)	488			(111		)	(117		)	—		(47		)	655		(1		)
Total asset-backed	928		(12		)	49			610			(345		)	(218		)	75		(160		)	927		(1		)
Total fixed maturity securities	1,203		(9		)	52			657			(378		)	(234		)	107		(215		)	1,183		(1		)
Equity securities	11		3			(6		)	16			(8		)	—			—		—			16		—
Life settlement contracts	88		33			—			—			—			(39		)	—		—			82		8
Separate account business	1		—			—			—			—			—			—		(1		)	—		—
Total	$	1,303	$	27		$	46		$	673		$	(386	)	$	(273	)	$	107	$	(216	)	$	1,281	$	7
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 December 31, 2013 recognized in net income (loss)*
(In millions)	January 1,																	Level 3		of Level 3			December 31,
	2013																						2013
Fixed maturity securities:
Corporate and other bonds	$	219	$	3		$	—		$	142		$	(116	)	$	(44	)	$	51	$	(51	)	$	204	$	(2	)
States, municipalities and political subdivisions	96		(2		)	4			122			(79		)	(61		)	18		(27		)	71		—
Asset-backed:
Residential mortgage-backed	413		4			(14		)	116			(10		)	(75		)	4		(107		)	331		(3		)
Commercial mortgage-backed	129		—			11			107			(3		)	(11		)	21		(103		)	151		—
Other asset-backed	368		5			(4		)	314			(197		)	(35		)	—		(5		)	446		(2		)
Total asset-backed	910		9			(7		)	537			(210		)	(121		)	25		(215		)	928		(5		)
Redeemable preferred stock	26		(1		)	—			—			—			(25		)	—		—			—		—
Total fixed maturity securities	1,251		9			(3		)	801			(405		)	(251		)	94		(293		)	1,203		(7		)
Equity securities	34		(27		)	3			2			—			—			—		(1		)	11		(27		)
Other invested assets, including derivatives, net	—		—			—			—			(1		)	1			—		—			—		—
Short term investments	6		—			—			—			(6		)	—			—		—			—		—
Life settlement contracts	100		13			—			—			—			(25		)	—		—			88		(2		)
Separate account business	2		—			—			1			(2		)	—			—		—			1		—
Total	$	1,393	$	(5	)	$	—		$	804		$	(414	)	$	(275	)	$	94	$	(294	)	$	1,303	$	(36	)
* Net realized and unrealized gains and losses shown above are reported in Net income (loss) as follows:
Major Category of Assets and Liabilities		Consolidated Statements of Operations Line Items
Fixed maturity securities available-for-sale		Net realized investment gains (losses)
Fixed maturity securities trading		Net investment income
Equity securities		Net realized investment gains (losses)
Other invested assets - Derivative financial instruments held in a trading portfolio		Net investment income
Other invested assets - Derivative financial instruments not held in a trading portfolio		Net realized investment gains (losses)
Other invested assets - Overseas deposits		Net investment income
Life settlement contracts		Other revenues
Other liabilities - Derivative financial instruments		Net realized investment gains (losses)
Securities shown on the previous page may be transferred in or out of levels within the fair value hierarchy based on the availability of observable market information and quoted prices used to determine the fair value of the security. The availability of observable market information and quoted prices varies based on market conditions and trading volume. During the year ended December 31, 2014 there were $24 million of transfers from Level 2 to Level 1 and $1 million from Level 1 to Level 2. There were no transfers between Level 1 and Level 2 during the year ended December 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.
Derivative Financial Investments
Level 1 securities include exchange traded derivatives, primarily futures, valued using quoted market prices. Level 2 securities primarily include the embedded derivative on funds withheld liability and currency forwards. The embedded derivative on funds withheld liability is valued using the change in fair value of the assets supporting the funds withheld payable, which are fixed maturity securities valued with observable inputs. Currency forwards are valued using observable market forward rates. Over-the-counter derivatives, principally interest rate swaps, total return swaps, equity warrants and options, are valued using inputs including broker/dealer quotes and are classified within Level 3 of the valuation hierarchy due to a lack of transparency as to whether these quotes are based on information that is observable in the marketplace.
Overseas Deposits
Overseas deposits, which can be redeemed at net asset value in 90 days or less, are classified as Level 2.
Short Term Investments
Securities that are actively traded or have quoted prices are classified as Level 1. These securities include money market funds and treasury bills. Level 2 primarily includes commercial paper, for which all inputs are market observable. Fixed maturity securities purchased within one year of maturity are classified consistent with fixed maturity securities discussed above. Short term investments as presented in the tables above differ from the amounts presented on the 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 included fixed maturity securities, equities and short term investments. The valuation methodologies and inputs for these asset types have been described above.
Significant Unobservable Inputs
The table below presents quantitative information about the significant unobservable inputs utilized by the Company in the fair value measurements of Level 3 assets. Valuations for assets and liabilities not presented in the table below are primarily based on broker/dealer quotes for which there is a lack of transparency as to inputs used to develop the valuations. The quantitative detail of these unobservable inputs is neither provided nor reasonably available to the Company.
31-Dec-14
Assets	Fair Value		Valuation Technique(s)		Unobservable Input(s)	Range
(In millions)						(Weighted Average)
Fixed maturity securities	$	101	Discounted cash flow		Credit spread	2% - 13% (3%)
Equity securities	16		Market approach		Private offering price	$12 - $4,391 per share ($600)
Life settlement contracts	82		Discounted cash flow		Discount rate risk premium	9%
					Mortality assumption	55% - 1676% (163%)
31-Dec-13
Assets	Fair Value		Valuation Technique(s)		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 to the credit spread assumptions would result in a lower fair value measurement. For equity securities, an increase in the private offering price would result in a higher fair value measurement. For life settlement contracts, an increase in the discount rate risk premium or decrease in the mortality assumption would result in a lower fair value measurement.
Financial Assets and Liabilities Not Measured at Fair Value
The carrying amount and estimated fair value of the Company's financial instrument assets and liabilities which are not measured at fair value on the Consolidated Balance Sheets are listed in the tables below.
December 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	$	1	$	—		$	—		$	1		$	1
Mortgage loans	588		—			—			608			608
Financial liabilities
Long term debt	$	2,559	$	—		$	2,883		$	—		$	2,883
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 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.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Note E. Income Taxes
	The CNA Tax Group is included in the consolidated federal income tax return of Loews and its eligible subsidiaries. Loews and the Company have agreed that for each taxable year, the Company will 1) be paid by Loews the amount, if any, by which the Loews consolidated federal income tax liability is reduced by virtue of the inclusion of the CNA Tax Group in the Loews consolidated federal income tax return, or 2) pay to Loews an amount, if any, equal to the federal income tax that would have been payable by the CNA Tax Group filing a separate consolidated tax return. In the event that Loews should have a net operating loss in the future computed on the basis of filing a separate consolidated tax return without the CNA Tax Group, the Company may be required to repay tax recoveries previously received from Loews. This agreement may be canceled by either party upon 30 days written notice.
	For the years ended December 31, 2014 and 2013, the Company paid $287 million and $89 million to Loews related to federal income taxes. For the year ended December 31, 2012, the Company received from Loews $75 million related to federal income taxes.
	For 2012 through 2014, the IRS has accepted Loews and the Company into the Compliance Assurance Process (CAP), which is a voluntary program for large corporations. Under CAP, the IRS conducts a real-time audit and works contemporaneously with the Company to resolve any issues prior to the filing of the tax return. The Company believes that this approach should reduce tax-related uncertainties, if any.
	At December 31, 2014 and 2013, there were no unrecognized tax benefits.
	The Company recognizes interest accrued related to: 1) unrecognized tax benefits in Interest expense and 2) tax refund claims in Other revenues on the Consolidated Statements of Operations. The Company recognizes penalties (if any) in Income tax (expense) benefit on the Consolidated Statements of Operations. During 2014 and 2013, the Company recognized no interest and no penalties. During 2012, the Company recognized $2 million of interest income and no penalties. There were no amounts accrued for interest or penalties at December 31, 2014 or 2013.
	The following table provides a reconciliation between the Company's federal income tax expense at statutory rates and the recorded income tax expense, excluding discontinued operations.
	Tax Reconciliation
	Years ended December 31
	(In millions)	2014			2013			2012
	Income tax expense at statutory rates	$	(423	)	$	(447	)	$	(301	)
	Tax benefit from tax exempt income	119			97			84
	Foreign taxes and credits	(6		)	(1		)	(13		)
	Other tax expense	(9		)	(10		)	(9		)
	Income tax expense	$	(319	)	$	(361	)	$	(239	)
	At December 31, 2014, no deferred taxes are required on the undistributed earnings of subsidiaries subject to tax.
	The following table provides the current and deferred components of the Company's income tax expense, excluding taxes on discontinued operations.
	Current and Deferred Taxes
	Years ended December 31
	(In millions)	2014			2013			2012
	Current tax expense	$	(318	)	$	(292	)	$	(94	)
	Deferred tax expense	(1		)	(69		)	(145		)
	Total income tax expense	$	(319	)	$	(361	)	$	(239	)
	Total income tax presented above includes foreign tax expense of approximately $24 million, $24 million and $34 million related to income from continuing foreign operations of approximately $66 million, $101 million and $88 million for the years ended December 31, 2014, 2013 and 2012.
	The deferred tax effects of the significant components of the Company's deferred tax assets and liabilities are set forth in the table below.
	Components of Net Deferred Tax Asset
	31-Dec
	(In millions)	2014			2013
	Deferred Tax Assets:
	Insurance reserves:
	Property and casualty claim and claim adjustment expense reserves	$	265		$	289
	Unearned premium reserves	187			178
	Receivables	35			50
	Employee benefits	289			187
	Life settlement contracts	46			46
	Deferred retroactive reinsurance benefit	61			66
	Other assets	138			149
	Gross deferred tax assets	1,021			965
	Deferred Tax Liabilities:
	Investment valuation differences	50			68
	Deferred acquisition costs	226			232
	Net unrealized gains	489			383
	Other liabilities	65			62
	Gross deferred tax liabilities	830			745
	Net deferred tax asset	$	191		$	220
	At December 31, 2014, the CNA Tax Group had no loss carryforwards or tax credit carryforwards.
	Although realization of deferred tax assets is not assured, management believes it is more likely than not that the recognized net deferred tax asset will be realized through recoupment of ordinary and capital taxes paid in prior carryback years and through future earnings, reversal of existing temporary differences and available tax planning strategies. As a result, no valuation allowance was recorded at December 31, 2014 or 2013.

Claim_and_Claim_Adjustment_Exp

Claim and Claim Adjustment Expense Reserves	12 Months Ended
	Dec. 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 $156 million, $169 million and $391 million for the years ended December 31, 2014, 2013 and 2012. Catastrophe losses in 2012 included Storm Sandy.
	The table below provides a reconciliation between beginning and ending claim and claim adjustment expense reserves, including claim and claim adjustment expense reserves of the life company as of and for the years ended December 31, 2014, 2013 and 2012.
	Reconciliation of Claim and Claim Adjustment Expense Reserves
	As of and for the years ended December 31
	(In millions)	2014			2013			2012
	Reserves, beginning of year:
	Gross	$	24,089		$	24,763		$	24,303
	Ceded	4,972			5,126			5,020
	Net reserves, beginning of year	19,117			19,637			19,283
	Change in net reserves due to acquisition (disposition) of subsidiaries	(13		)	—			291
	Net incurred claim and claim adjustment expenses:
	Provision for insured events of current year	5,043			5,114			5,273
	Decrease in provision for insured events of prior years	(36		)	(115		)	(182		)
	Amortization of discount	161			154			145
	Total net incurred (a)	5,168			5,153			5,236
	Net payments attributable to:
	Current year events	(945		)	(981		)	(988		)
	Prior year events	(4,355		)	(4,588		)	(4,280		)
	Total net payments	(5,300		)	(5,569		)	(5,268		)
	Foreign currency translation adjustment and other	(45		)	(104		)	95
	Net reserves, end of year	18,927			19,117			19,637
	Ceded reserves, end of year	4,344			4,972			5,126
	Gross reserves, end of year	$	23,271		$	24,089		$	24,763
	(a)	Total net incurred above does not agree to Insurance claims and policyholders' benefits as reflected on the Consolidated Statements of Operations due to amounts related to retroactive reinsurance deferred gain accounting, uncollectible reinsurance and loss deductible receivables, and benefit expenses related to future policy benefits and policyholders' funds, which are not reflected in the table above.
	The changes in provision for insured events of prior years (net prior year claim and claim adjustment expense reserve development, including unallocated claim and claim adjustment expense) were as follows.
	Reserve Development
	Years ended December 31
	(In millions)	2014			2013			2012
	Property and casualty reserve development	$	(39	)	$	(115	)	$	(180	)
	Life reserve development in life company	3			—			(2		)
	Total	$	(36	)	$	(115	)	$	(182	)
	The following tables summarize the gross and net carried reserves as of December 31, 2014 and 2013.
	Gross and Net Carried Claim and Claim Adjustment Expense Reserves
	December 31, 2014	Specialty			Commercial			International			Life &			Corporate			Total
	(In millions)										Group Non-Core			& Other Non-Core
	Gross Case Reserves	$	2,136		$	5,298		$	752		$	2,881		$	1,189		$	12,256
	Gross IBNR Reserves	4,093			4,216			689			302			1,715			11,015
	Total Gross Carried Claim and Claim Adjustment Expense Reserves	$	6,229		$	9,514		$	1,441		$	3,183		$	2,904		$	23,271
	Net Case Reserves	$	1,929		$	4,947		$	598		$	2,572		$	144		$	10,190
	Net IBNR Reserves	3,726			3,906			663			271			171			8,737
	Total Net Carried Claim and Claim Adjustment Expense Reserves	$	5,655		$	8,853		$	1,261		$	2,843		$	315		$	18,927
	December 31, 2013	Specialty			Commercial			International			Life &			Corporate			Total
	(In millions)										Group Non-Core			& Other Non-Core
	Gross Case Reserves	$	2,001		$	5,570		$	803		$	2,748		$	1,140		$	12,262
	Gross IBNR Reserves	4,057			4,521			772			310			2,167			11,827
	Total Gross Carried Claim and Claim Adjustment Expense Reserves	$	6,058		$	10,091		$	1,575		$	3,058		$	3,307		$	24,089
	Net Case Reserves	$	1,793		$	5,119		$	629		$	2,352		$	283		$	10,176
	Net IBNR Reserves	3,789			3,992			705			271			184			8,941
	Total Net Carried Claim and Claim Adjustment Expense Reserves	$	5,582		$	9,111		$	1,334		$	2,623		$	467		$	19,117
	Net Prior Year Development
	Changes in estimates of claim and allocated claim adjustment expense reserves and premium accruals, net of reinsurance, for prior years are defined as net prior year development. These changes can be favorable or unfavorable. The following tables and discussion include the net prior year development recorded for Specialty, Commercial, International and Corporate & Other Non-Core segments for the years ended December 31, 2014, 2013 and 2012.
	Favorable net prior year development of $14 million, $9 million and $11 million was recorded in the Life & Group Non-Core segment for the years ended December 31, 2014, 2013 and 2012.
	Net Prior Year Development
	Year ended December 31, 2014
	(In millions)	Specialty			Commercial			International			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(136	)	$	176		$	(59	)	$	(2	)	$	(21	)
	Pretax (favorable) unfavorable premium development	(13		)	(20		)	2			(1		)	(32		)
	Total pretax (favorable) unfavorable net prior year development	$	(149	)	$	156		$	(57	)	$	(3	)	$	(53	)
	Year ended December 31, 2013
(In millions)	Specialty			Commercial			International			Corporate			Total
										& Other
										Non-Core
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(196	)	$	122		$	(38	)	$	(6	)	$	(118	)
Pretax (favorable) unfavorable premium development	(14		)	(8		)	(21		)	1			(42		)
Total pretax (favorable) unfavorable net prior year development	$	(210	)	$	114		$	(59	)	$	(5	)	$	(160	)
Year ended December 31, 2012
(In millions)	Specialty			Commercial			International			Corporate			Total
										& Other
										Non-Core
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(93	)	$	(25	)	$	(74	)	$	(13	)	$	(205	)
Pretax (favorable) unfavorable premium development	(14		)	(36		)	3			1			(46		)
Total pretax (favorable) unfavorable net prior year development	$	(107	)	$	(61	)	$	(71	)	$	(12	)	$	(251	)
Premium development can occur in the property and casualty business when there is a change in exposure on auditable policies or when premium accruals differ from processed premium.  Audits on policies usually occur in a period after the expiration date of the policy.
For the year ended December 31, 2013, favorable premium development for International was recorded related to a commutation as discussed later in this note.
Specialty
The following table provides further detail of the net prior year claim and allocated claim adjustment expense reserve development (development) recorded for the Specialty segment for the years ended December 31, 2014, 2013 and 2012.
Years ended December 31
(In millions)	2014			2013			2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
Medical Professional Liability	$	39		$	(27	)	$	(34	)
Other Professional Liability and Management Liability	(87		)	(73		)	19
Surety	(82		)	(74		)	(63		)
Warranty	(2		)	(3		)	(5		)
Other	(4		)	(19		)	(10		)
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(136	)	$	(196	)	$	(93	)
2014
Unfavorable development for medical professional liability was primarily related to increased frequency of large medical products liability class action lawsuits in accident years 2012 and prior and increased frequency of other large medical professional liability losses in accident years 2011 through 2013.
Overall, favorable development for other professional liability and management liability was related to better than expected severity in accident years 2008 through 2011, including favorable outcomes on individual large claims. Additional favorable development related to lower than expected frequency in accident years 2011 through 2013. Unfavorable development was recorded due to higher than expected severity in financial institution and professional service coverages in accident years 2009 through 2011.
Favorable development for surety coverages was primarily due to better than expected large loss emergence in accident years 2012 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.
Overall, favorable development for other professional liability and management liability was related to better than expected loss emergence in accident years 2010 and prior. Unfavorable development was recorded in accident year 2011 related to an increase in severity in management liability.
Favorable development for surety coverages was primarily due to better than expected large loss emergence in accident years 2011 and prior.
Other includes standard property and casualty coverages provided to Specialty customers. Favorable development for other coverages was primarily due to better than expected loss emergence in property coverages primarily in accident years 2010 and subsequent.
2012
Favorable development for medical professional liability was primarily due to better than expected loss emergence in accident years 2008 and prior.
Overall, unfavorable development for other professional liability and management liability was primarily due to increased frequency and severity in our lawyer coverages in accident years 2008 through 2011, a large claim settlement in 2005 related to lawyers and increased frequency of large claims in public company directors and officers coverages related to the financial crisis in accident year 2011. Favorable development was recorded primarily due to better than expected loss emergence in accident years 2003 through 2009.
Favorable development for surety coverages was primarily due to better than expected loss emergence in accident years 2010 and prior.
Overall, favorable development for other coverages was primarily due to favorable loss emergence in property and workers' compensation coverages in accident years 2005 and subsequent. Unfavorable development was recorded in accident year 2009 primarily due to an unfavorable outcome on an individual general liability claim.
Commercial
The following table provides further detail of the development recorded for the Commercial segment for the years ended December 31, 2014, 2013 and 2012.
Years ended December 31
(In millions)	2014			2013			2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
Commercial Auto	$	31		$	18		$	25
General Liability	45			64			(66		)
Workers' Compensation	139			91			15
Property and Other	(39		)	(51		)	1
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	176		$	122		$	(25	)
2014
Unfavorable development for commercial auto was primarily related to higher than expected frequency in accident years 2012 and 2013 and higher than expected severity for liability coverages in accident years 2010 through 2013. Favorable development was recorded related to fewer large claims than expected in accident years 2008 and 2009.
Overall, unfavorable development for general liability was primarily related to higher than expected severity in accident years 2010 through 2013. Favorable development was recorded primarily related to lower than expected frequency of large losses in accident years 2005 through 2009.
Overall, unfavorable development for workers’ compensation was primarily due to increased medical severity in accident years 2010 and prior, higher than expected severity related to Defense Base Act (DBA) contractors in accident years 2010 through 2013 and the recognition of losses related to favorable premium development in accident year 2013. Favorable development of $26 million was recorded in accident years 1996 and prior related to the commutation of a workers’ compensation reinsurance pool.
Favorable development for property and other first-party coverages was recorded in accident years 2013 and prior, primarily related to fewer claims than expected and favorable individual claim settlements.
2013
Unfavorable development for commercial auto coverages was primarily due to higher than expected frequency in accident years 2011 and 2012 and large loss emergence in accident years 2009 and 2010.
Unfavorable development for general liability coverages was primarily related to increased incurred loss severity in accident years 2010 through 2012.
Unfavorable development for workers' compensation includes the Company's response to legislation enacted during 2013 related to the New York Fund for Reopened Cases. The law change necessitated an increase in reserves as re-opened workers' compensation claims can no longer be turned over to the state for handling and payment after December 31, 2013. Additional unfavorable development was recorded in accident year 2012 related to increased frequency and severity on claims related to DBA contractors and in accident year 2010 due to higher than expected large losses and increased severity in the state of California.
Favorable development for property and other coverages was primarily related to favorable outcomes on litigated catastrophe claims in accident years 2005 and 2010 as well as favorable loss emergence in non-catastrophe losses in accident years 2010 through 2012.
2012
Unfavorable development for commercial auto coverages was primarily due to higher than expected loss emergence in accident years 2007 and subsequent and higher than expected frequency in accident year 2011.
Overall, favorable development for general liability coverages was primarily due to better than expected loss emergence in accident years 2006 and subsequent related to umbrella business and 2003 and prior related to large account business. Unfavorable development was recorded in accident years 2009 through 2011 related to several large losses.
Overall, unfavorable development for workers' compensation was primarily due to increased medical severity in accident years 2010 and 2011 and the recognition of losses related to favorable premium development in accident year 2011. Favorable development was recorded in accident years 2001 and prior reflecting favorable experience.
International
The following table provides further detail of the development recorded for the International segment for the years ended December 31, 2014, 2013 and 2012.
Years ended December 31
(In millions)	2014			2013			2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
Medical Professional Liability	$	(7	)	$	(7	)	$	1
Other Professional Liability	(26		)	(30		)	(41		)
Liability	(13		)	(8		)	(2		)
Property & Marine	(14		)	13			(30		)
Other	(9		)	(17		)	(2		)
Commutations	10			11			—
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(59	)	$	(38	)	$	(74	)
2014
Overall, favorable development for other professional liability was primarily related to better than expected severity in accident years 2012 and prior. Unfavorable development was recorded in accident year 2008 due to financial crisis claims.
Favorable development for liability was primarily related to better than expected frequency and severity in accident years 2009 and subsequent.
Favorable development for property and marine coverages primarily related to better than expected frequency of large claims in accident years 2012 and prior.
Favorable development for other coverages was a result of better than expected frequency in Hardy, primarily in financial institution coverages.
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.
2013
Overall, favorable development for other professional liability was primarily related to better than expected severity in accident years 2011 and prior. Unfavorable development was recorded related to higher than expected severity in accident year 2012.
Overall, unfavorable development for property and marine coverages was primarily due to 2011 catastrophe events, including the Thailand floods and the New Zealand Lyttelton earthquake, and one large non-catastrophe claim. Favorable development was recorded related to better than expected severity in accident years 2008 through 2011.
Favorable development for other coverages was largely a result of better than expected severity in Hardy in accident year 2012.
The commutation of a third-party capital provider's 15% participation in the 2012 year of account resulted in recognition of the 15% share of year of account premiums, losses and expenses.
2012
Favorable development for other professional liability was primarily related to better than expected severity in accident years 2007 and prior.
Favorable development for property and marine coverages related to better than expected severity in accident years 2011 and prior.
A&EP Reserves
In 2010, Continental Casualty Company (CCC) together with several of the Company’s insurance subsidiaries completed a transaction with National Indemnity Company (NICO), a subsidiary of Berkshire Hathaway Inc., under which substantially all of the Company’s legacy A&EP liabilities were ceded to NICO (Loss Portfolio Transfer or LPT). Under the terms of the NICO transaction, the Company ceded approximately $1.6 billion of net A&EP claim and allocated claim adjustment expense reserves to NICO under a retroactive reinsurance agreement with an aggregate limit of $4 billion. The $1.6 billion of claim and allocated claim adjustment expense reserves ceded to NICO was net of $1.2 billion of ceded claim and allocated claim adjustment expense reserves under existing third-party reinsurance contracts. The NICO aggregate reinsurance limit also covers credit risk on the existing third-party reinsurance related to these liabilities. The Company paid NICO a reinsurance premium of $2 billion and transferred to NICO billed third-party reinsurance receivables related to A&EP claims with a net book value of $215 million, resulting in total consideration of $2.2 billion.
The following table displays the impact of the Loss Portfolio Transfer on the Consolidated Statements of Operations.
Years ended December 31
(In millions)	2014			2013			2012
Net A&EP adverse development before consideration of LPT	$	—		$	363		$	261
Provision for uncollectible third-party reinsurance on A&EP	—			140			—
Additional amounts ceded under LPT	—			503			261
Retroactive reinsurance benefit recognized	(13		)	(314		)	(261		)
Pretax impact of unrecognized deferred retroactive reinsurance benefit	$	(13	)	$	189		$	—
During 2013 and 2012, unfavorable development was recorded for accident years 2000 and prior related to A&EP claims due to an increase in ultimate claim severity and higher than anticipated claim reporting, as well as increased defense costs. Additionally, in 2013 the Company recognized a provision for uncollectible third-party reinsurance which increased the expected recovery from NICO. The fourth quarter 2014 A&EP reserve review was not completed. Additional information and analysis on inuring third-party reinsurance recoveries are needed to finalize the review. The Company expects to complete the review in the first half of 2015.
In the fourth quarter of 2013, the cumulative amounts ceded under the Loss Portfolio Transfer of $2.5 billion exceeded the $2.2 billion consideration paid, resulting in a $189 million deferred retroactive reinsurance gain. This deferred benefit is recognized in earnings in proportion to actual recoveries under the Loss Portfolio Transfer. Over the life of the contract, there is no economic impact as long as any additional losses are within the limit under the contract. In 2014, $13 million of the deferred retroactive reinsurance benefit was recognized, and the remaining unrecognized benefit at December 31, 2014 was $176 million.
NICO established a collateral trust account as security for its obligations to the Company. The fair value of the collateral trust account at December 31, 2014 was $3.4 billion. In addition, Berkshire Hathaway Inc. guaranteed the payment obligations of NICO up to the full aggregate reinsurance limit as well as certain of NICO’s performance obligations under the trust agreement. NICO is responsible for claims handling and billing and collection from third-party reinsurers related to the Company’s A&EP claims.

Legal_Proceedings_and_Continge

Legal Proceedings and Contingent Liabilities	12 Months Ended
	Dec. 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 Consolidated Financial Statements.

Reinsurance

Reinsurance	12 Months Ended
	Dec. 31, 2014
Reinsurance Disclosures [Abstract]
Reinsurance	Note H. Reinsurance
	The Company cedes insurance to reinsurers to limit its maximum loss, provide greater diversification of risk, minimize exposures on larger risks and to exit certain lines of business. The ceding of insurance does not discharge the primary liability of the Company. A credit exposure exists with respect to property and casualty and life reinsurance ceded to the extent that any reinsurer is unable to meet its obligations or to the extent that the reinsurer disputes the liabilities assumed under reinsurance agreements. Property and casualty reinsurance coverages are tailored to the specific risk characteristics of each product line and the Company's retained amount varies by type of coverage. Reinsurance contracts are purchased to protect specific lines of business such as property and workers' compensation. Corporate catastrophe reinsurance is also purchased for property and workers' compensation exposure. Currently, most reinsurance contracts are purchased on an excess of loss basis. The Company also utilizes facultative reinsurance in certain lines. In addition, the Company assumes reinsurance, primarily through Hardy and as a member of various reinsurance pools and associations.
	The following table summarizes the amounts receivable from reinsurers at December 31, 2014 and 2013.
	Components of Reinsurance Receivables
	31-Dec
	(In millions)	2014			2013
	Reinsurance receivables related to insurance reserves:
	Ceded claim and claim adjustment expenses	$	4,344		$	4,972
	Ceded future policy benefits	185			733
	Ceded policyholders' funds	—			35
	Reinsurance receivables related to paid losses	213			348
	Reinsurance receivables	4,742			6,088
	Allowance for uncollectible reinsurance	(48		)	(71		)
	Reinsurance receivables, net of allowance for uncollectible reinsurance	$	4,694		$	6,017
	The Company has established an allowance for uncollectible reinsurance receivables. The Company reviews the allowance quarterly and adjusts the allowance as necessary to reflect changes in estimates of uncollectible balances. The allowance may also be reduced related to write-offs of reinsurance receivable balances.
	The Company attempts to mitigate its credit risk related to reinsurance by entering into reinsurance arrangements with reinsurers that have credit ratings above certain levels, and by obtaining collateral. On a limited basis, the Company may enter into reinsurance agreements with reinsurers that are not rated, primarily captive reinsurers. The primary methods of obtaining collateral are through reinsurance trusts, letters of credit and funds withheld balances. Such collateral was approximately $3.4 billion and $3.9 billion at December 31, 2014 and 2013.
	The Company's largest recoverables from a single reinsurer at December 31, 2014, including ceded unearned premium reserves were approximately $2,565 million from subsidiaries of Berkshire Hathaway Group, $244 million from subsidiaries of the Hartford Insurance Group and $185 million from subsidiaries of Wilton Re. The recoverable from the Berkshire Hathaway Group includes amounts related to third-party reinsurance for which NICO has assumed the credit risk under the terms of the Loss Portfolio Transfer as discussed in Note F to the Consolidated Financial Statements.
	The effects of reinsurance on earned premiums and written premiums for the years ended December 31, 2014, 2013 and 2012 are shown in the following tables.
	Components of Earned Premiums
	(In millions)	Direct			Assumed			Ceded		Net		Assumed/
												Net %
	2014 Earned Premiums
	Property and casualty	$	9,452		$	277		$	3,073	$	6,656	4.2	%
	Accident and health	508			48			—		556		8.6	%
	Total earned premiums	$	9,960		$	325		$	3,073	$	7,212	4.5	%
	2013 Earned Premiums
	Property and casualty	$	9,063		$	258		$	2,609	$	6,712	3.8	%
	Accident and health	511			48			—		559		8.6	%
	Total earned premiums	$	9,574		$	306		$	2,609	$	7,271	4.2	%
	2012 Earned Premiums
	Property and casualty	$	8,354		$	197		$	2,229	$	6,322	3.1	%
	Accident and health	512			47			—		559		8.4	%
	Total earned premiums	$	8,866		$	244		$	2,229	$	6,881	3.5	%
	Components of Written Premiums
	(In millions)	Direct			Assumed			Ceded		Net		Assumed/
												Net %
	2014 Written Premiums
	Property and casualty	$	9,283		$	276		$	3,024	$	6,535	4.2	%
	Accident and health	504			49			—		553		8.9	%
	Total written premiums	$	9,787		$	325		$	3,024	$	7,088	4.6	%
	2013 Written Premiums
	Property and casualty	$	9,103		$	249		$	2,556	$	6,796	3.7	%
	Accident and health	505			47			—		552		8.5	%
	Total written premiums	$	9,608		$	296		$	2,556	$	7,348	4	%
	2012 Written Premiums
	Property and casualty	$	8,467		$	169		$	2,225	$	6,411	2.6	%
	Accident and health	506			47			—		553		8.5	%
	Total written premiums	$	8,973		$	216		$	2,225	$	6,964	3.1	%
	Included in the direct and ceded earned premiums for the years ended December 31, 2014, 2013 and 2012 are $2,643 million, $2,156 million and $1,794 million related to property business that is 100% reinsured under a significant third-party captive program. The third-party captives that participate in this program are affiliated with the non-insurance company policyholders, therefore this program provides a means for the policyholders to self-insure this property risk. The Company receives and retains a ceding commission.
	Accident and health premiums are from long duration contracts; property and casualty premiums are from short duration contracts.
	Insurance claims and policyholders' benefits reported on the Consolidated Statements of Operations are net of reinsurance recoveries of $1,379 million, $1,450 million and $1,443 million for the years ended December 31, 2014, 2013 and 2012, including $1,458 million, $712 million and $814 million related to the significant third-party captive program discussed above. Reinsurance recoveries in 2014 were unfavorably affected by the commutation of a workers’ compensation reinsurance pool.

Debt

Debt	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Note I. Debt
	Debt is composed of the following obligations.
	31-Dec
	(In millions)	2014			2013
	Short term debt:
	Senior notes of CNAF, 5.850%, face amount of $549, due December 15, 2014	$	—		$	549
	Long term debt:
	Senior notes of CNAF:
	6.500%, face amount of $350, due August 15, 2016	349			349
	6.950%, face amount of $150, due January 15, 2018	150			149
	7.350%, face amount of $350, due November 15, 2019	348			348
	5.875%, face amount of $500, due August 15, 2020	497			497
	5.750%, face amount of $400, due August 15, 2021	397			397
	3.950%, face amount of $550, due May 15, 2024	547			—
	Debenture of CNAF, 7.250%, face amount of $243, due November 15, 2023	241			241
	Subordinated variable rate debt of Hardy, face amount of $30, due September 15, 2036	30			30
	Total long term debt	2,559			2,011
	Total debt	$	2,559		$	2,560
	CCC is a member of the Federal Home Loan Bank of Chicago (FHLBC). FHLBC membership provides participants with access to additional sources of liquidity through various programs and services. As a requirement of membership in the FHLBC, CCC held $16 million of FHLBC stock as of December 31, 2014 and 2013 giving it access to approximately $330 million of additional liquidity. As of December 31, 2014 and 2013, CCC had no outstanding borrowings from the FHLBC.
	The Company has a four-year $250 million senior unsecured revolving credit facility with a syndicate of banks which is intended to be used for general corporate purposes. At the Company's election, the commitments under the credit agreement may be increased from time to time up to an additional aggregate amount of $100 million. Under the credit agreement, the Company is required to pay a facility fee which would adjust automatically in the event of a change in the Company's financial ratings. The credit agreement includes several covenants, including maintenance of a minimum consolidated net worth and a specified ratio of consolidated indebtedness to consolidated total capitalization. The minimum consolidated net worth, as defined as of December 31, 2014, was $8.6 billion. As of December 31, 2014 and 2013, we had no outstanding borrowings under the credit agreement. The credit facility expires in 2016.
	The Company's debt obligations contain customary covenants for investment grade issuers. The Company was in compliance with all covenants as of and for the years ended December 31, 2014 and 2013.
	The combined aggregate maturities for debt at December 31, 2014 are presented in the following table.
	Maturity of Debt
	(In millions)
	2015	$	—
	2016	350
	2017	—
	2018	150
	2019	350
	Thereafter	1,723
	Less discount	(14		)
	Total	$	2,559

Benefit_Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Benefit Plans	Note J. Benefit Plans
	Pension and Postretirement Health Care Benefit Plans
	CNA sponsors noncontributory defined benefit pension plans, primarily through the CNA Retirement Plan, covering certain eligible employees. These plans are closed to new entrants.
	Effective January 1, 2000, the CNA Retirement Plan was closed to new participants. Existing participants at that time were given a choice to either continue to accrue benefits under the CNA Retirement Plan or to cease accruals at December 31, 1999. Employees who chose to continue to accrue benefits under the plan will receive a benefit based on their years of credited service and highest 60 months of compensation at termination. Compensation is defined as regular salary, eligible bonuses and overtime. Employees who elected to cease accruals at December 31, 1999 received the present value of their accrued benefit in an accrued pension account that is credited with interest based on the annual rate of interest on 30-year Treasury securities. These employees also receive certain enhanced employer contributions in the CNA Savings and Capital Accumulation Plan.
	CNA's funding policy for defined benefit pension plans is to make contributions in accordance with applicable governmental regulatory requirements with consideration of the funded status of the plans.
	During 2014, the CNA Retirement Plan offered a limited-time lump sum settlement payment opportunity to the majority of the terminated vested participants of the plan. The lump sum settlements reduce the Company’s risk and volatility related to funding the CNA Retirement Plan. The number of participants that elected to accept the lump sum opportunity was approximately 20% of the then total participants in the plan. The settlement payments of $253 million were made from CNA Retirement Plan assets. The $84 million settlement charge recorded by the Company in the fourth quarter of 2014 represents recognition of a portion of the unrecognized actuarial losses previously reflected in AOCI. This settlement charge is included in Other operating expenses within the Corporate & Other Non-Core segment.
	CNA provides certain health care benefits to eligible retired employees, their covered dependents and their beneficiaries primarily through the CNA Health and Group Benefits Program. These postretirement benefits have largely been eliminated for active employees.
	In the second quarter of 2014, the Company eliminated certain postretirement medical benefits associated with the CNA Health and Group Benefits Program. This change was a negative plan amendment which resulted in an $86 million curtailment gain reported in Other operating expenses within the Corporate & Other Non-Core segment. In connection with the plan amendment, the Company remeasured the plan benefit obligation which resulted in a decrease in the discount rate used to determine the benefit obligation from 3.60% to 3.10%.
	The following table provides a reconciliation of benefit obligations and plan assets for the years ended December 31, 2014 and 2013.
	Funded Status
		Pension Benefits								Postretirement Benefits
	(In millions)	2014				2013				2014			2013
	Benefit obligation at January 1	$	2,943			$	3,271			$	40		$	47
	Changes in benefit obligation:
	Service cost	9				12				—			1
	Interest cost	132				121				1			1
	Participants' contributions	—				—				5			5
	Plan amendments	(3		)		—				(7		)	—
	Actuarial (gain) loss	367				(289		)		1			(3		)
	Benefits paid	(165		)		(165		)		(11		)	(12		)
	Settlements	(257		)		(8		)		—			—
	Foreign currency translation and other	(7		)		1				—			1
	Benefit obligation at December 31	3,019				2,943				29			40
	Fair value of plan assets at January 1	2,656				2,425				—			—
	Change in plan assets:
	Actual return on plan assets	216				311				—			—
	Company contributions	12				92				6			7
	Participants' contributions	—				—				5			5
	Benefits paid	(165		)		(165		)		(11		)	(12		)
	Settlements	(257		)		(8		)		—			—
	Foreign currency translation and other	(6		)		1				—			—
	Fair value of plan assets at December 31	2,456				2,656				—			—
	Funded status	$	(563	)		$	(287	)		$	(29	)	$	(40	)
	Amounts recognized on the Consolidated Balance Sheets at December 31:
	Other assets	$	9			$	9			$	—		$	—
	Other liabilities	(572		)		(296		)		(29		)	(40		)
	Net amount recognized	$	(563	)		$	(287	)		$	(29	)	$	(40	)
	Amounts recognized in Accumulated other comprehensive income, not yet recognized in net periodic cost (benefit):
	Prior service credit	$	—			$	—			$	(9	)	$	(98	)
	Net actuarial loss	974				745				8			8
	Net amount recognized	$	974			$	745			$	(1	)	$	(90	)
	The accumulated benefit obligation for all defined benefit pension plans was $2,962 million and $2,889 million at December 31, 2014 and 2013.
	The components of net periodic cost (benefit) are presented in the following table.
	Net Periodic Cost (Benefit)
	Years ended December 31
	(In millions)	2014				2013				2012
	Pension cost (benefit)
	Service cost	$	9			$	12			$	12
	Interest cost on projected benefit obligation	132				121				135
	Expected return on plan assets	(191		)		(181		)		(171		)
	Amortization of net actuarial loss	25				47				39
	Settlement loss	84				3				—
	Net periodic pension cost (benefit)	$	59			$	2			$	15
	Postretirement cost (benefit)
	Service cost	$	—			$	1			$	—
	Interest cost on projected benefit obligation	1				1				2
	Amortization of prior service credit	(10		)		(18		)		(18		)
	Amortization of net actuarial loss	1				2				1
	Curtailment gain	(86		)		—				—
	Net periodic postretirement cost (benefit)	$	(94	)		$	(14	)		$	(15	)
	The amounts recognized in Other comprehensive income are presented in the following table.
	Years ended December 31
	(In millions)	2014				2013				2012
	Pension and postretirement benefits
Amounts arising during the period	$	(337	)		$	422			$	(195	)
Curtailment and other	(81		)		—				—
Settlement	84				—				—
Reclassification adjustment relating to prior service credit	(10		)		(18		)		(18		)
Reclassification adjustment relating to actuarial loss	26				49				40
Total increase (decrease) in Other comprehensive income	$	(318	)		$	453			$	(173	)
The table below presents the estimated amounts to be recognized from AOCI into net periodic cost (benefit) during 2015.
(In millions)		Pension				Postretirement Benefits
		Benefits
Amortization of prior service credit		$	—			$	(2	)
Amortization of net actuarial loss		38				1
Total estimated amounts to be recognized		$	38			$	(1	)
Actuarial assumptions used for the CNA Retirement Plan and CNA Health and Group Benefits Program to determine benefit obligations are set forth in the following table.
Actuarial Assumptions for Benefit Obligations
31-Dec	2014			2013
Pension benefits
Discount rate	3.85	%		4.65	%
Expected long term rate of return	7.5			7.5
Rate of compensation increases	3.92			3.99
Postretirement benefits
Discount rate	2.5	%		3.6	%
Actuarial assumptions used for the CNA Retirement Plan and CNA Health and Group Benefits Program to determine net cost or benefit are set forth in the following table.
Actuarial Assumptions for Net Cost or Benefit
Years ended December 31	2014			2013			2012
Pension benefits
Discount rate	4.65	%		3.8	%		4.6	%
Expected long term rate of return	7.5			7.75			8
Rate of compensation increases	3.99			4.066			4.125
Postretirement benefits
Discount rate	3.600%/3.100%			2.8	%		3.75	%
In determining the expected long term rate of return on plan assets assumption for the CNA Retirement Plan, CNA considered the historical performance of the benefit plan investment portfolio as well as long term market return expectations based on the investment mix of the portfolio.
The CNA Health and Group Benefits Program has limited its share of the health care trend rate to a cost-of-living adjustment of 4% per year. For all participants, the employer subsidy on health care costs will not increase by more than 4% per year. As a result, the assumed health care cost trend rate used in measuring the accumulated postretirement benefit obligation for the CNA Health and Group Benefits Program was 4% per year in 2014, 2013 and 2012.
CNA employs a total return approach whereby a mix of equity, limited partnerships and fixed maturity securities are used to maximize the long term return of retirement plan assets for a prudent level of risk and to manage cash flows according to plan requirements. The target allocation of plan assets is 40% to 60% invested in equity securities and limited partnerships, with the remainder primarily invested in fixed maturity securities. The intent of this strategy is to minimize the Company's expense related to funding the plan by generating investment returns that exceed the growth of the plan liabilities over the long run. Risk tolerance is established after careful consideration of the plan liabilities, plan funded status and corporate financial conditions. In addition, alternative investments, including limited partnerships, are used to enhance risk adjusted long term returns while improving portfolio diversification. At December 31, 2014, the plan had committed approximately $107 million to future capital calls from various third-party limited partnership investments in exchange for an ownership interest in the related partnerships. Derivatives may be used to gain market exposure in an efficient and timely manner. Investment risk is measured and monitored on an ongoing basis through annual liability measurements, periodic asset/liability studies and quarterly investment portfolio reviews.
Pension plan assets measured at fair value on a recurring basis as well as cash are summarized below.
December 31, 2014
(In millions)		Level 1				Level 2				Level 3			Total Assets
													at Fair Value
Assets
Fixed maturity securities:
Corporate and other bonds		$	—			$	463			$	15		$	478
States, municipalities and political subdivisions		—				80				—			80
Asset-backed:
Residential mortgage-backed		—				123				—			123
Commercial mortgage-backed		—				75				—			75
Other asset-backed		—				12				—			12
Total asset-backed		—				210				—			210
U.S. Treasury and obligations of government-sponsored enterprises		25				—				—			25
Total fixed maturity securities		25				753				15			793
Equity securities		389				118				—			507
Derivative financial instruments		1				—				—			1
Short term investments		33				101				—			134
Limited partnerships:
Hedge funds		—				562				303			865
Private equity		—				—				113			113
Total limited partnerships		—				562				416			978
Other assets		—				30				—			30
Cash		13				—				—			13
Total assets		$	461			$	1,564			$	431		$	2,456
December 31, 2013
(In millions)		Level 1				Level 2				Level 3			Total Assets
													at Fair Value
Assets
Fixed maturity securities:
Corporate and other bonds		$	—			$	505			$	15		$	520
States, municipalities and political subdivisions		—				73				—			73
Asset-backed:
Residential mortgage-backed		—				130				—			130
Commercial mortgage-backed		—				106				—			106
Other asset-backed		—				12				—			12
Total asset-backed		—				248				—			248
Total fixed maturity securities		—				826				15			841
Equity securities		480				117				8			605
Derivative financial instruments		2				—				—			2
Short term investments		45				49				—			94
Limited partnerships:
Hedge funds		—				647				322			969
Private equity		—				—				114			114
Total limited partnerships		—				647				436			1,083
Other assets		—				31				—			31
Total assets		$	527			$	1,670			$	459		$	2,656
The limited partnership investments are recorded at fair value, which represents the plan's share of net asset value of each partnership, as determined by the General Partner. Level 2 includes limited partnership investments which can be redeemed at net asset value in 90 days or less. Level 3 includes limited partnership investments with withdrawal provisions greater than 90 days, or for which withdrawals are not permitted until the termination of the partnership. Within hedge fund strategies, approximately 57% are equity related, 37% pursue a multi-strategy approach and 6% are focused on distressed investments at December 31, 2014.
For a discussion of the fair value levels and the valuation methodologies used to measure fixed maturity securities, equities, derivatives and short term investments, see Note D to the Consolidated Financial Statements.
The tables below present a reconciliation for all pension plan assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the years ended December 31, 2014 and 2013.
Level 3	Balance at January 1, 2014				Actual return on assets still held at December 31, 2014				Actual return on assets sold during the year ended December 31, 2014			Purchases, sales and settlements			Net transfers into (out of) Level 3			Balance at December 31, 2014
(In millions)
Fixed maturity securities:
Corporate and other bonds	$	15			$	—			$	—		$	—		$	—		$	15
Equity securities	8				—				—			(8		)	—			—
Limited partnerships:
Hedge funds	322				19				—			(38		)	—			303
Private equity	114				19				—			(20		)	—			113
Total limited partnerships	436				38				—			(58		)	—			416
Total	$	459			$	38			$	—		$	(66	)	$	—		$	431
Level 3	Balance at January 1, 2013				Actual return on assets still held at December 31, 2013				Actual return on assets sold during the year ended December 31, 2013			Purchases, sales and settlements			Net transfers into (out of) Level 3			Balance at December 31, 2013
(In millions)
Fixed maturity securities:
Corporate and other bonds	$	11			$	(1	)		$	—		$	5		$	—		$	15
Equity securities	5				3				—			—			—			8
Limited partnerships:
Hedge funds	359				56				—			(77		)	(16		)	322
Private equity	62				—				—			52			—			114
Total limited partnerships	421				56				—			(25		)	(16		)	436
Investment contracts with insurance company	10				—				—			(10		)	—			—
Total	$	447			$	58			$	—		$	(30	)	$	(16	)	$	459
The table below presents the estimated future minimum benefit payments to participants at December 31, 2014.
Estimated Future Minimum Benefit Payments to Participants
(In millions)	Pension Benefits				Postretirement Benefits
2015	$	179			$	5
2016	181				4
2017	180				4
2018	184				4
2019	185				3
2020-2024	936				9
In 2015, CNA expects to contribute $14 million to its pension plans and $5 million to its postretirement health care benefit plans.
Savings Plans
CNA sponsors savings plans, which are generally contributory plans that allow most employees to contribute a maximum of 50% of their eligible compensation, subject to certain limitations prescribed by the IRS. The Company contributes matching amounts to participants, amounting to 70% of the first 6% (35% of the first 6% in the first year of employment) of eligible compensation contributed by the employee. Employees vest in these contributions ratably over five years.
As noted above, during 2000, employees were required to make a choice regarding their continued participation in the CNA Retirement Plan. Employees who elected to forgo earning additional benefits in the CNA Retirement Plan and all employees hired on or after January 1, 2000 receive a Company contribution of 3% or 5% of their eligible compensation, depending on their age. In addition, these employees are eligible to receive additional discretionary contributions of up to 2% of eligible compensation and an additional Company match of up to 80% of the first 6% of eligible compensation contributed by the employee. These additional contributions are made at the discretion of management and are contributed to participant accounts in the first quarter of the year following management's determination of the discretionary amounts. Employees vest in these contributions ratably over five years.
Benefit expense for the Company's savings plans was $69 million, $71 million and $70 million for the years ended December 31, 2014, 2013 and 2012.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation [Text Block]	Note K. Stock-Based Compensation
	The CNAF Incentive Compensation Plan (the Plan), as amended and restated on January 1, 2010, authorizes the grant of stock-based compensation to certain management personnel for up to 6 million shares of CNAF's common stock. The Plan currently provides for awards of stock options, stock appreciation rights (SARs), restricted shares, performance-based restricted share units (RSUs) and performance share units. The number of shares available for the granting of stock-based compensation under the Plan as of December 31, 2014 was approximately 1.5 million.
	The Company recorded stock-based compensation expense related to the Plan of $11 million, $10 million and $9 million for the years ended December 31, 2014, 2013 and 2012. The related income tax benefit recognized was $4 million, $3 million and $3 million for the years ended December 31, 2014, 2013, and 2012. The compensation cost related to non-vested awards not yet recognized was $13 million, and the weighted average period over which it is expected to be recognized is 1.7 years at December 31, 2014.
	Equity based compensation that is not fully vested prior to termination is generally forfeited upon termination, except as otherwise provided by contractual obligations. In addition, any such compensation that vested prior to termination is generally canceled immediately, except in cases of retirement, death or disability, and as otherwise provided by contractual obligations.
	Share Awards
	The fair value of share awards is based on the market value of the Company's common stock as of the date of grant. Share awards currently granted under the Plan include restricted shares, performance-based RSUs and performance share units. Generally, restricted shares vest ratably over a four-year service period following the date of grant. Performance-based RSUs generally become payable within a range of 0% to 100% of the number of shares initially granted based upon the attainment of specific annual performance goals and vest ratably over a four-year service period following the date of grant. Performance share units become payable within a range of 0% to 200% of the number of shares initially granted based upon the attainment of specific performance goals achieved over a three year period.
	The following table presents activity for non-vested restricted shares, performance-based RSUs and performance share units under the Plan in 2014.
		Number of Awards		Weighted-Average Grant Date Fair Value
	Balance at January 1, 2014	847,674		$	29.61
	Awards granted	261,273		41.01
	Awards vested	(156,332	)	28.42
	Awards forfeited, canceled or expired	(91,002	)	32.09
	Performance-based adjustment	52,568		28.5
	Balance at December 31, 2014	914,181		$	32.76
	Stock Options and SARs
	The exercise price of all stock options and SARs granted is based on the market value of the Company's common stock as of the date of grant. Stock options and SARs generally vest ratably over a four-year service period following date of grant and have a maximum term of ten years.
	The fair value of granted stock options and SARs was estimated at the grant date using the Black-Scholes option-pricing model. The Black-Scholes model incorporates a risk free rate of return and various assumptions regarding the underlying common stock and the expected life of the securities granted. Different interest rates and assumptions were used for each grant, as appropriate based on date of grant.
	There were no stock options or SARs granted for the years ended December 31, 2014 and 2013. For the year ended December 31, 2012 there were 10 thousand awards granted. As of December 31, 2014, there were approximately 1 million awards outstanding, fully vested and expected to vest and exercisable. The fair value of awards vested was $1 million for the years ended December 31, 2014, 2013 and 2012.

Other_Intangible_Assets

Other Intangible Assets	12 Months Ended
	Dec. 31, 2014
Intangible Assets, Gross (Excluding Goodwill) [Abstract]
Other Intangible Assets	Note L. Other Intangible Assets
	Other intangible assets are presented in the following table.
	31-Dec		2014				2013
	(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	$	60	$	61	$	64	$	63
	Trade name	8 years	8		3		8		2
	Distribution channel	15 years	12		2		13		1
	Total finite-lived intangible assets		80		66		85		66
	Indefinite-lived intangible assets:
	Syndicate capacity		55				58
	Agency force		16				16
	Total indefinite-lived intangible assets		71				74
	Total other intangible assets		$	151	$	66	$	159	$	66
	The Company's other intangible assets primarily relate to the purchase of Hardy. For the years ended December 31, 2014, 2013 and 2012 amortization expense of $2 million, $15 million and $33 million was included in Amortization of deferred acquisition costs and $1 million, $5 million and $10 million was included in Other operating expenses in the Statement of Operations for the International 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 other intangible assets is $1 million in 2015 and $2 million in years 2016, 2017, 2018 and 2019.

Operating_Leases_Commitments_a

Operating Leases, Commitments and Contingencies, and Guarantees	12 Months Ended
	Dec. 31, 2014
Operating Leases, Commitments and Contingencies, and Guarantees [Abstract]
Operating Leases, Commitments and Contingencies, and Guarantees	Note M. Operating Leases, Commitments and Contingencies and Guarantees
	Operating Leases
	The Company occupies office facilities under lease agreements that expire at various dates. In addition, data processing, office and transportation equipment is leased under agreements that expire at various dates. Most leases contain renewal options that provide for rent increases based on prevailing market conditions. Lease expenses for the years ended December 31, 2014, 2013 and 2012 were $55 million, $46 million and $52 million. Sublease revenues for the years ended December 31, 2014, 2013 and 2012 were $1 million, $3 million and $2 million.
	The table below presents the future minimum lease payments to be made under non-cancelable operating leases along with future minimum sublease receipts to be received on owned and leased properties at December 31, 2014.
	Future Minimum Lease Payments and Sublease Receipts
	(In millions)	Future Minimum Lease Payments		Future Minimum Sublease Receipts
	2015	$	36	$	—
	2016	35		—
	2017	30		—
	2018	25		—
	2019	21		1
	Thereafter	98		1
	Total	$	245	$	2
	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 December 31, 2014 that the Company could be required to pay under this guarantee, in excess of amounts already recorded, were approximately $50 million. If the Company were required to assume the entire lease obligation, the Company would have the right to pursue reimbursement from the other shareholders and the right to all sublease revenues.
	Guarantees
	As of December 31, 2014 and December 31, 2013, the Company had recorded liabilities of approximately $5 million and $7 million related to guarantee and indemnification agreements and management believes that it is not likely that any future indemnity claims will be significantly greater than the amounts recorded.
	In the course of selling business entities and assets to third parties, the Company agreed to guarantee the performance of certain obligations of a previously owned subsidiary and to indemnify purchasers for losses arising out of breaches of representation and warranties with respect to the business entities or assets being sold, including, in certain cases, losses arising from undisclosed liabilities or certain named litigation.  Such guarantee and indemnification agreements may include provisions that survive indefinitely. As of December 31, 2014, the aggregate amount of quantifiable guarantee and indemnification agreements in effect for sales of business entities, assets and third-party loans was $375 million and $324 million.  Should the Company be required to make payments under the guarantee, it would have the right to seek reimbursement in certain cases from an affiliate of a previously owned subsidiary.
	In addition, the Company has agreed to provide indemnification to third-party purchasers for certain losses associated with sold business entities or assets that are not limited by a contractual monetary amount. As of December 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. Certain provisions of the indemnification agreements survive indefinitely while others survive until the applicable statutes of limitation expire or until the agreed-upon contract terms expire.
	In the normal course of business, the Company also provided guarantees, if the primary obligor fails to perform, to holders of structured settlement annuities provided by a previously owned subsidiary, which are estimated to mature through 2120. The potential amount of future payments the Company could be required to pay under these guarantees was approximately $1.9 billion at December 31, 2014. The Company does not believe a payable is likely under these guarantees, as the Company is the beneficiary of a trust that must be maintained at a level that approximates the discounted reserves for these annuities.

Stockholders_Equity_and_Statut

Stockholders' Equity and Statutory Accounting Practices	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity and Statutory Accounting Practices [Abstract]
Stockholders' Equity And Statutory Accounting Practices	Note N. Stockholders’ Equity and Statutory Accounting Practices
	Common Stock Dividends
	There are no restrictions on the retained earnings or net income of CNAF with regard to payment of dividends to its stockholders. However, given the holding company nature of CNAF, its ability to pay a dividend is significantly dependent on the receipt of dividends from its subsidiaries, particularly CCC, which directly or indirectly owns all significant subsidiaries. See the Statutory Accounting Practices section below for a discussion of the regulatory restrictions on CCC's availability to pay dividends.
	CNAF's ability to pay dividends is indirectly limited by the minimum consolidated net worth covenant in the Company's line of credit agreement. See Note I to the Consolidated Financial Statements for further discussion of the Company's debt obligations.
	Statutory Accounting Practices
	CNAF’s insurance subsidiaries are domiciled in various jurisdictions. These subsidiaries prepare statutory financial statements in accordance with accounting practices prescribed or permitted by the respective jurisdictions’ insurance regulators. Domestic prescribed statutory accounting practices are set forth in a variety of publications of the National Association of Insurance Commissioners (NAIC) as well as state laws, regulations and general administrative rules. These statutory accounting principles vary in certain respects from GAAP. In converting from statutory accounting principles to GAAP, the more significant adjustments include deferral of policy acquisition costs and the inclusion of net unrealized holding gains or losses in stockholders’ equity relating to certain fixed maturity securities.
	The payment of dividends by CNAF's insurance subsidiaries without prior approval of the insurance department of each subsidiary’s domiciliary jurisdiction is generally limited by formula. Dividends in excess of these amounts are subject to prior approval by the respective insurance regulator.
	Dividends from CCC are subject to the insurance holding company laws of the State of Illinois, the domiciliary state of CCC. Under these laws, ordinary dividends, or dividends that do not require prior approval by the Department are determined based on statutory net income and surplus as well as timing of dividends paid in the preceding twelve months. Ordinary dividends may only be paid from earned surplus, which is calculated by removing unrealized gains from unassigned surplus. As of December 31, 2014, CCC is in a positive earned surplus position, enabling CCC to pay approximately $466 million of dividend payments during 2015 that would not be subject to the Department’s prior approval. The actual level of dividends paid in any year is determined after an assessment of available dividend capacity, holding company liquidity and cash needs as well as the impact the dividends will have on the statutory surplus of the applicable insurance company.
	Combined statutory capital and surplus and net income (loss), determined in accordance with accounting practices prescribed or permitted by insurance and/or other regulatory authorities for the Combined Continental Casualty Companies and the life company, were as follows.
	Statutory Information
		Statutory Capital and Surplus				Statutory Net Income (Loss)
		31-Dec				Years ended December 31
	(In millions)	2014 (a)		2013 (b)		2014 (a)		2013		2012
	Combined Continental Casualty Companies	$	11,155	$	11,137	$	914	$	913	$	391
	Life company			597		37		48		44
	________________
	(a)	Information derived from the statutory-basis financial statements to be filed with insurance regulators.
	(b)	Represents the combined statutory surplus of CCC and its subsidiaries, including the life company.
	CNAF’s domestic insurance subsidiaries are subject to risk-based capital (RBC) requirements. RBC is a method developed by the NAIC to determine the minimum amount of statutory capital appropriate for an insurance company to support its overall business operations in consideration of its size and risk profile. The formula for determining the amount of RBC specifies various factors, weighted based on the perceived degree of risk, which are applied to certain financial balances and financial activity. The adequacy of a company's actual capital is evaluated by a comparison to the RBC results, as determined by the formula. Companies below minimum RBC requirements are classified within certain levels, each of which requires specified corrective action.
	The statutory capital and surplus presented above for CCC was approximately 270% and 265% of company action level RBC at December 31, 2014 and 2013. Company action level RBC is the level of RBC which triggers a heightened level of regulatory supervision. The statutory capital and surplus of the Company's foreign insurance subsidiaries, which is not significant to the overall statutory capital and surplus, also met or exceeded their respective regulatory and other capital requirements.
	The Hardy entities are not owned by CCC, therefore their regulatory capital is not included in the Statutory Capital and Surplus of the Combined Continental Casualty Companies presented in the table above. At December 31, 2014, Hardy's portion of Syndicate 382's capital requirement included $105 million of capital provided by CCC which is included in Combined Continental Casualty Companies' Statutory Capital and Surplus above.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss) by Component	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss) by Component	Note O. Accumulated Other Comprehensive Income (Loss) by Component
	The table below displays the changes in Accumulated other comprehensive income (loss) by component for the years ended December 31, 2014 and 2013.
		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 December 31, 2013	$	26		$	692		$	—		$	(426	)	$	150		$	442
	Change due to sale of subsidiaries	(5		)	(17		)	22			—			—			—
	Other comprehensive income (loss) before reclassifications	15			295			12			(219		)	(95		)	8
	Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(10), $(23), $7, $0 and $(26)	—			28			34			(12		)	—			50
	Other comprehensive income (loss) after tax (expense) benefit of $(8), $(122), $15, $111, $0 and $(4)	15			267			(22		)	(207		)	(95		)	(42		)
	Balance at December 31, 2014	$	36		$	942		$	—		$	(633	)	$	55		$	400
		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 December 31, 2012	$	20		$	1,371		$	(721	)	$	161		$	831
	Other comprehensive income (loss) before reclassifications	6			(658		)	275			(11		)	(388		)
	Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(10), $11, $0 and $1	—			21			(20		)	—			1
	Other comprehensive income (loss) after tax (expense) benefit of $(3), $364, $(158), $0 and $203	6			(679		)	295			(11		)	(389		)
	Balance at December 31, 2013	$	26		$	692		$	(426	)	$	150		$	442
	Amounts reclassified from Accumulated other comprehensive income (loss) shown above are reported in Net income (loss) as follows:
	Component of AOCI		Consolidated Statements of Operations Line Item Affected by Reclassifications
	Net unrealized gains (losses) on investments with OTTI losses		Net realized investment gains (losses)
	Net unrealized gains (losses) on other investments		Net realized investment gains (losses)
	Net unrealized gains (losses) on discontinued operations		Income (loss) from discontinued operations
	Pension and postretirement benefits		Other operating expenses

Business_Segments

Business Segments	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Business Segments	Note P. Business Segments
	The Company's core property and casualty commercial insurance operations are aggregated and reported in three business segments: Specialty, Commercial and International. Specialty provides a broad array of professional, financial and specialty property and casualty products and services, through a network of independent agents, brokers and managing general underwriters. Commercial includes property and casualty coverages sold to small businesses and middle market entities and organizations primarily through an independent agency distribution system. Commercial also includes commercial insurance and risk management products sold to large corporations primarily through insurance brokers. International provides management and professional liability coverages as well as a broad range of other property and casualty insurance products and services abroad through a network of brokers, independent agencies and managing general underwriters, as well as the Lloyd’s marketplace.
	The Company's non-core operations are managed in two segments: Life & Group Non-Core and Corporate & Other Non-Core. Life & Group Non-Core primarily includes the results of our individual and group long term care businesses that are in run-off. Corporate & Other Non-Core primarily includes certain corporate expenses, including interest on corporate debt, and the results of certain property and casualty business in run-off, including CNA Re and A&EP.
	The accounting policies of the segments are the same as those described in Note A to the Consolidated Financial Statements. 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. Consistent with the Consolidated Balance Sheet presentation, the comparative period continues to reflect CAC assets and liabilities. 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.
	Approximately 8.8%, 9.0% and 9.2% of the Company's direct written premiums were derived from outside the United States for the years ended December 31, 2014, 2013 and 2012.
	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 Company's results of operations and selected balance sheet items by segment are presented in the following tables.
	Year ended December 31, 2014	Specialty			Commercial			International			Life &			Corporate
											Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Net written premiums	$	2,839		$	2,817		$	880		$	553		$	1		$	(2	)	$	7,088
	Operating revenues
	Net earned premiums	$	2,838		$	2,906		$	913		$	556		$	1		$	(2	)	$	7,212
	Net investment income	560			723			61			700			23			—			2,067
	Other revenues	295			38			—			16			12			(5		)	356
	Total operating revenues	3,693			3,667			974			1,272			36			(7		)	9,635
	Claims, Benefits and Expenses
	Net incurred claims and benefits	1,627			2,187			488			1,304			(29		)	—			5,577
	Policyholders’ dividends	6			8			—			—			—			—			14
	Amortization of deferred acquisition costs	592			493			204			28			—			—			1,317
	Other insurance related expenses	262			487			151			130			1			(2		)	1,029
	Other expenses	254			31			28			30			210			(5		)	548
	Total claims, benefits and expenses	2,741			3,206			871			1,492			182			(7		)	8,485
	Operating income (loss) from continuing operations before income tax	952			461			103			(220		)	(146		)	—			1,150
	Income tax (expense) benefit on operating income (loss)	(318		)	(154		)	(34		)	151			54			—			(301		)
	Net operating income (loss) from continuing operations	634			307			69			(69		)	(92		)	—			849
	Net realized investment gains (losses), pretax	15			16			(1		)	7			20			—			57
	Income tax (expense) benefit on net realized investment gains (losses)	(5		)	(6		)	1			—			(8		)	—			(18		)
	Net realized investment gains (losses)	10			10			—			7			12			—			39
	Net income (loss) from continuing operations	$	644		$	317		$	69		$	(62	)	$	(80	)	$	—		$	888
	December 31, 2014
	(In millions)
	Reinsurance receivables	$	567		$	690		$	207		$	525		$	2,753		$	—		$	4,742
	Insurance receivables	778			954			250			13			2			—			1,997
	Deferred acquisition costs	304			213			83			—			—			—			600
	Goodwill	117			—			35			—			—			—			152
	Insurance reserves
	Claim and claim adjustment expenses	6,229			9,514			1,441			3,183			2,904			—			23,271
	Unearned premiums	1,763			1,273			431			125			—			—			3,592
	Future policy benefits	—			—			—			9,490			—			—			9,490
	Policyholders’ funds	9			18			—			—			—			—			27
	Year ended December 31, 2013	Specialty			Commercial			International			Life &			Corporate
											Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Net written premiums	$	2,880		$	2,960		$	959		$	552		$	(1	)	$	(2	)	$	7,348
	Operating revenues
	Net earned premiums	$	2,795		$	3,004		$	916		$	559		$	(1	)	$	(2	)	$	7,271
	Net investment income	629			899			60			662			32			—			2,282
	Other revenues	257			96			—			(4		)	12			(2		)	359
	Total operating revenues	3,681			3,999			976			1,217			43			(4		)	9,912
	Claims, Benefits and Expenses
	Net incurred claims and benefits	1,593			2,259			489			1,261			191			—			5,793
	Policyholders’ dividends	6			7			—			—			—			—			13
	Amortization of deferred acquisition costs	585			526			223			28			—			—			1,362
	Other insurance related expenses	250			498			140			130			(3		)	(2		)	1,013
	Other expenses	237			32			12			13			183			(2		)	475
	Total claims, benefits and expenses	2,671			3,322			864			1,432			371			(4		)	8,656
	Operating income (loss) from continuing operations before income tax	1,010			677			112			(215		)	(328		)	—			1,256
	Income tax (expense) benefit on operating income (loss)	(342		)	(229		)	(43		)	141			118			—			(355		)
	Net operating income (loss) from continuing operations	668			448			69			(74		)	(210		)	—			901
	Net realized investment gains (losses), pretax	(5		)	(15		)	5			26			9			—			20
	Income tax (expense) benefit on net realized investment gains (losses)	2			5			(2		)	(8		)	(3		)	—			(6		)
	Net realized investment gains (losses)	(3		)	(10		)	3			18			6			—			14
Net income (loss) from continuing operations	$	665		$	438		$	72		$	(56	)	$	(204	)	$	—		$	915
December 31, 2013
(In millions)
Reinsurance receivables	$	500		$	1,024		$	294		$	1,203		$	3,067		$	—		$	6,088
Insurance receivables	732			1,019			299			11			2			—			2,063
Deferred acquisition costs	299			226			99			—			—			—			624
Goodwill	117			—			38			—			—			—			155
Insurance reserves
Claim and claim adjustment expenses	6,058			10,091			1,575			3,058			3,307			—			24,089
Unearned premiums	1,710			1,374			506			128			—			—			3,718
Future policy benefits	—			—			—			10,471			—			—			10,471
Policyholders’ funds	9			15			—			92			—			—			116
Year ended December 31, 2012	Specialty			Commercial						Life &			Corporate
										Group			& Other
(In millions)							International(a)			Non-Core			Non-Core			Eliminations			Total
Net written premiums	$	2,733		$	3,033		$	648		$	553		$	(1	)	$	(2	)	$	6,964
Operating revenues
Net earned premiums	$	2,709		$	2,968		$	647		$	559		$	—		$	(2	)	$	6,881
Net investment income	564			826			59			629			32			—			2,110
Other revenues	231			41			(1		)	33			16			(1		)	319
Total operating revenues	3,504			3,835			705			1,221			48			(3		)	9,310
Claims, Benefits and Expenses
Net incurred claims and benefits	1,746			2,370			361			1,255			(16		)	—			5,716
Policyholders’ dividends	2			11			—			—			—			—			13
Amortization of deferred acquisition costs	574			520			152			28			—			—			1,274
Other insurance related expenses	278			532			94			142			3			(2		)	1,047
Other expenses	207			37			7			22			183			(1		)	455
Total claims, benefits and expenses	2,807			3,470			614			1,447			170			(3		)	8,505
Operating income (loss) from continuing operations before income tax	697			365			91			(226		)	(122		)	—			805
Income tax (expense) benefit on operating income (loss)	(235		)	(120		)	(40		)	134			41			—			(220		)
Net operating income (loss) from continuing operations	462			245			51			(92		)	(81		)	—			585
Net realized investment gains (losses), pretax	18			34			7			(9		)	4			—			54
Income tax (expense) benefit on net realized investment gains (losses)	(8		)	(11		)	(1		)	3			(2		)	—			(19		)
Net realized investment gains (losses)	10			23			6			(6		)	2			—			35
Net income (loss) from continuing operations	$	472		$	268		$	57		$	(98	)	$	(79	)	$	—		$	620
____________________
(a)	International includes Hardy from the date of acquisition.
The following table provides revenue by line of business for each reportable segment. Revenues are comprised of operating revenues and net realized investment gains and losses.
Revenues by Line of Business
Years ended December 31
(In millions)	2014			2013			2012
Specialty
Management & Professional Liability	$	2,818		$	2,836		$	2,723
Surety	509			490			485
Warranty & Alternative Risks	381			350			314
Specialty revenues	3,708			3,676			3,522
Commercial
Middle Market	1,631			1,642			1,560
Small Business	709			754			669
Other Commercial Insurance	1,343			1,588			1,640
Commercial revenues	3,683			3,984			3,869
International
Canada	273			289			276
CNA Europe	335			326			313
Hardy	365			366			123
International revenues	973			981			712
Life & Group Non-Core revenues	1,279			1,243			1,212
Corporate & Other Non-Core revenues	56			52			52
Eliminations	(7		)	(4		)	(3		)
Total revenues	$	9,692		$	9,932		$	9,364

Discontinued_Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Note Q. Discontinued Operations
	The results of discontinued operations reflected in the Consolidated Statements of Operations were as follows:
	Years ended December 31
	(In millions)	2014			2013			2012
	Revenues
	Net earned premiums	$	—		$	—		$	1
	Net investment income	94			168			172
	Net realized investment gains	3			11			9
	Other revenues	—			2			1
	Total revenues	97			181			183
	Claims, Benefits and Expenses
	Insurance claims and policyholders' benefits	75			141			167
	Other operating expenses	2			3			3
	Total claims, benefits and expenses	77			144			170
	Income before income tax	20			37			13
	Income tax expense	(6		)	(15		)	(5		)
	Income from operations of discontinued operations, net of income tax	14			22			8
	Loss on sale, net of income tax benefit of $40, $0 and $0	(211		)	—			—
	(Loss) income from discontinued operations	$	(197	)	$	22		$	8
	The disposal group included $3,550 million of assets and $3,297 million of liabilities as of August 1, 2014.

Quarterly_Financial_Data_Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Data [Abstract]
Quarterly Financial Data (Unaudited)	Note R. Quarterly Financial Data (Unaudited)
	The following tables set forth unaudited quarterly financial data for the years ended December 31, 2014 and 2013.
	Quarterly Financial Data
	2014
	(In millions, except per share data)	First		Second		Third		Fourth		Full Year
	Revenues	$	2,463	$	2,440	$	2,411	$	2,378	$	9,692
	Net income (loss) (a)	$	13	$	267	$	213	$	198	$	691
	Basic earnings (loss) per share	$	0.05	$	0.99	$	0.79	$	0.73	$	2.56
	Diluted earnings (loss) per share	$	0.05	$	0.98	$	0.79	$	0.73	$	2.55
	2013
	(In millions, except per share data)	First		Second		Third		Fourth		Full Year
	Revenues	$	2,455	$	2,450	$	2,458	$	2,569	$	9,932
	Net income (loss)	$	250	$	194	$	272	$	221	$	937
	Basic earnings (loss) per share	$	0.93	$	0.72	$	1.01	$	0.82	$	3.48
	Diluted earnings (loss) per share (b)	$	0.93	$	0.72	$	1.01	$	0.82	$	3.47
	____________________
	(a)	Net income in the first quarter of 2014 includes the impairment loss on the sale of CAC.
	(b)	Due to the averaging of shares, quarterly earnings per share do not add to the total for the full year.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	Note S. Related Party Transactions
	The Company reimburses Loews, or pays directly, for fees and expenses of investment facilities and services provided to the Company. The amounts incurred by the Company for these fees and expenses were $39 million, $37 million and $36 million for the years ended December 31, 2014, 2013 and 2012 and amounts due to Loews, included in Other liabilities and payable in the first quarter of the subsequent year, were $21 million and $19 million as of December 31, 2014 and 2013. In addition, the Company reimbursed Loews for general corporate services and related travel expenses of $4 million for the years ended December 31, 2013 and 2012. The CNA Tax Group is included in the consolidated federal income tax return of Loews and its eligible subsidiaries, and the related payable to Loews, included in Other liabilities, was $132 million and $178 million as of December 31, 2014 and 2013. For a detailed description of the income tax agreement with Loews see Note E to the Consolidated Financial Statements. In addition, the Company writes, at standard rates, a limited amount of insurance for Loews and its subsidiaries. The earned premiums for the years ended December 31, 2014, 2013 and 2012 were $2 million in each year.
	CNA previously sponsored a stock ownership plan whereby the Company financed the purchase of Company common stock by certain former officers, including executive officers. Interest charged on the principal amount of these outstanding stock purchase loans is generally equivalent to the short term applicable federal rate in effect on the disbursement date of the loan, compounded semi-annually. Loans made pursuant to the plan were full recourse and secured by the stock purchased. The loans were originally issued with a ten-year maturity date, and the remaining loan has been extended with current terms maturing through May 2016.

Schedule_I_Summary_of_Investme

Schedule I. Summary of Investments - Other Than Investments in Related Parties	12 Months Ended
	Dec. 31, 2014
Summary of Investments, Other than Investments in Related Parties [Abstract]
Schedule I. Summary of Investments - Other than Investments in Related Parties	SCHEDULE I. SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES
	Incorporated herein by reference to Note B to the Consolidated Financial Statements included under Item 8.

Schedule_II_Condensed_Financia

Schedule II. Condensed Financial Information of Registrant (Parent Company)	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule II. Condensed Financial Information of Registrant (Parent Company)	SCHEDULE II. CONDENSED FINANCIAL INFORMATION OF REGISTRANT (PARENT COMPANY)
	CNA Financial Corporation
	Statements of Operations and Comprehensive Income
	Years ended December 31
	(In millions)	2014			2013			2012
	Revenues
	Net investment income	$	1		$	1		$	1
	Net realized investment gains	4			4			4
	Other income	—			—			9
	Total revenues	5			5			14
	Expenses
	Administrative and general	5			(7		)	1
	Interest	182			165			164
	Total expenses	187			158			165
	Loss from operations before income taxes and equity in net income of subsidiaries	(182		)	(153		)	(151		)
	Income tax benefit	35			22			144
	Loss before equity in net income of subsidiaries	(147		)	(131		)	(7		)
	Equity in net income of subsidiaries	838			1,068			635
	Net income	691			937			628
	Equity in other comprehensive income of subsidiaries	(42		)	(389		)	351
	Total Comprehensive Income	$	649		$	548		$	979
	See accompanying Notes to Condensed Financial Information as well as the Consolidated Financial Statements and accompanying Notes.
	CNA Financial Corporation
	Balance Sheets
	31-Dec
	(In millions, except share data)	2014			2013
	Assets
	Investment in subsidiaries	$	14,867		$	14,708
	Cash	1			1
	Fixed maturity securities available-for-sale, at fair value (amortized cost of $1 and $1)	1			1
	Short term investments	499			505
	Amounts due from subsidiaries	—			3
	Other assets	3			3
	Total assets	$	15,371		$	15,221
	Liabilities
	Short term debt	$	—		$	549
	Long term debt	2,529			1,981
	Other liabilities	48			40
	Total liabilities	2,577			2,570
	Stockholders' Equity
	Common stock ($2.50 par value; 500,000,000 shares authorized; 273,040,243 shares issued; 269,980,202 and 269,717,583 shares outstanding)	683			683
	Additional paid-in capital	2,151			2,145
	Retained earnings	9,645			9,495
	Accumulated other comprehensive income	400			442
	Treasury stock (3,060,041 and 3,322,660 shares), at cost	(84		)	(91		)
	Notes receivable for the issuance of common stock	(1		)	(23		)
	Total stockholders' equity	12,794			12,651
	Total liabilities and stockholders' equity	$	15,371		$	15,221
	See accompanying Notes to Condensed Financial Information as well as the Consolidated Financial Statements and accompanying Notes.
	CNA Financial Corporation
	Statements of Cash Flows
	Years ended December 31
	(In millions)	2014			2013			2012
	Cash Flows from Operating Activities
	Net income	$	691		$	937		$	628
	Adjustments to reconcile net income to net cash flows provided by operating activities:
	Equity in net income of subsidiaries	(838		)	(1,068		)	(635		)
	Dividends received from subsidiaries	650			400			450
	Net realized investment gains	(4		)	(4		)	(4		)
	Other, net	14			8			19
	Total adjustments	(178		)	(664		)	(170		)
	Net cash flows provided by operating activities	513			273			458
	Cash Flows from Investing Activities
	Proceeds from fixed maturity securities	—			1			1
Change in short term investments	6			(57		)	(156		)
Capital contributions to subsidiaries	(10		)	(12		)	(399		)
Repayment of surplus note by subsidiary	—			—			250
Other, net	5			4			4
Net cash flows used by investing activities	1			(64		)	(300		)
Cash Flows from Financing Activities
Dividends paid to common stockholders	(541		)	(216		)	(162		)
Proceeds from the issuance of debt	546			—			—
Repayment of debt	(549		)	(3		)	—
Stock options exercised	5			2			1
Other, net	25			9			3
Net cash flows used by financing activities	(514		)	(208		)	(158		)
Net change in cash	—			1			—
Cash, beginning of year	1			—			—
Cash, end of year	$	1		$	1		$	—
See accompanying Notes to Condensed Financial Information as well as the Consolidated Financial Statements and accompanying Notes.
Notes to Condensed Financial Information
A. Basis of Presentation
The condensed financial information of CNA Financial Corporation (CNAF or the Parent Company) should be read in conjunction with the Consolidated Financial Statements and Notes thereto included in Item 8 of this Form 10-K. CNAF’s subsidiaries are accounted for using the equity method of accounting. Equity in net income of these subsidiaries is presented on the Condensed Statements of Operations as Equity in net income of subsidiaries. Loews owned approximately 90% of the outstanding common stock of CNAF as of December 31, 2014.
B. Commitments, Contingencies and Guarantees
As of December 31, 2014 CNAF had recorded liabilities of approximately $5 million related to indemnification agreements. The Parent Company believes that it is not likely that any future indemnity claims will be significantly greater than the amounts recorded. As of December 31, 2013 CNAF had no recorded liabilities related to guarantee or indemnification agreements.
In the course of selling business entities and assets to third parties, CNAF has agreed to guarantee the performance of certain obligations of both a previously owned subsidiary and a current subsidiary. Such obligations include agreement to indemnify purchasers for losses arising out of breaches of representation and warranties with respect to the business entities or assets sold, including, in certain cases, losses arising from undisclosed liabilities or certain named litigation. The guarantee agreements may include provisions that survive indefinitely. As of December 31, 2014, the aggregate amount of quantifiable guarantee agreements in effect for sales of business entities, assets and third-party loans was $625 million. Should the company be required to make payments under the guarantee, it would have the right to seek reimbursement in certain cases from an affiliate of a previously owned subsidiary.
In addition, CNAF 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 December 31, 2014, CNAF 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.
In the normal course of business, CNAF also provided guarantees, if the primary obligor fails to perform, to holders of structured settlement annuities provided by a previously owned subsidiary, which are estimated to mature through 2120. The potential amount of future payments CNAF could be required to pay under these guarantees was approximately $1.9 billion at December 31, 2014. The Parent Company does not believe a payable is likely under these guarantees, as it is the beneficiary of a trust that must be maintained at a level that approximates the discounted reserves for these annuities.

Schedule_III_Supplementary_Ins

Schedule III. Supplementary Insurance Information	12 Months Ended
	Dec. 31, 2014
Supplementary Insurance Information [Abstract]
Schedule III. Supplementary Insurance Information	SCHEDULE III. SUPPLEMENTARY INSURANCE INFORMATION
	Incorporated herein by reference to Note P to the Consolidated Financial Statements included under Item 8.

Schedule_IV_Reinsurance

Schedule IV. Reinsurance	12 Months Ended
	Dec. 31, 2014
Supplemental Schedule of Reinsurance Premiums for Insurance Companies [Abstract]
Schedule IV. Reinsurance	SCHEDULE IV. REINSURANCE
	Incorporated herein by reference to Note H to the Consolidated Financial Statements included under Item 8.

Schedule_V_Valuation_and_Quali

Schedule V. Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2014
Valuation and Qualifying Accounts [Abstract]
Schedule V. Valuation and Qualifying Accounts	SCHEDULE V. VALUATION AND QUALIFYING ACCOUNTS
	(In millions)	Balance at Beginning of Period		Charged to Costs and Expenses			Charged to Other Accounts (a)			Deductions			Balance at End of Period
	Year ended December 31, 2014
	Deducted from assets:
	Allowance for doubtful accounts:
	Insurance and reinsurance receivables	$	155	$	(40	)	$	(1	)	$	(5	)	$	109
	Year ended December 31, 2013
	Deducted from assets:
	Allowance for doubtful accounts:
	Insurance and reinsurance receivables	$	174	$	(6	)	$	(3	)	$	(10	)	$	155
	Year ended December 31, 2012
	Deducted from assets:
	Allowance for doubtful accounts:
	Insurance and reinsurance receivables	$	203	$	(23	)	$	5		$	(11	)	$	174
	(a)    Amount includes effects of foreign currency translation.

Schedule_VI_Supplemental_Infor

Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations	12 Months Ended
	Dec. 31, 2014
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]
Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations	SCHEDULE VI. SUPPLEMENTAL INFORMATION CONCERNING PROPERTY AND CASUALTY INSURANCE OPERATIONS
	As of and for the years ended December 31	Consolidated Property and Casualty Operations
	(In millions)	2014			2013			2012
	Deferred acquisition costs	$	600		$	624
	Reserves for unpaid claim and claim adjustment expenses	23,271			24,015
	Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.5% to 8.0%)	1,578			1,586
	Unearned premiums	3,592			3,718
	Net written premiums	7,088			7,348			$	6,964
	Net earned premiums	7,212			7,271			6,881
	Net investment income	2,031			2,240			2,074
	Incurred claim and claim adjustment expenses related to current year	5,043			5,113			5,266
	Incurred claim and claim adjustment expenses related to prior years	(39		)	(115		)	(180		)
	Amortization of deferred acquisition costs	1,317			1,362			1,274
	Paid claim and claim adjustment expenses	5,297			5,566			5,257

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014						Dec. 31, 2013
Accounting Policies [Abstract]
Consolidation	The accompanying Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). Intercompany amounts have been eliminated.
Use of Estimates	The preparation of 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 Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from those estimates.
Premiums	Premiums: Insurance premiums on property and casualty insurance contracts are recognized in proportion to the underlying risk insured which principally are earned ratably over the duration of the policies. Premiums on long term care contracts are earned ratably over the policy year in which they are due. The reserve for unearned premiums represents the portion of premiums written relating to the unexpired terms of coverage.
	Insurance receivables include balances due currently or in the future, including amounts due from insureds related to losses under high deductible policies, and are presented at unpaid balances, net of an allowance for uncollectible receivables. Amounts are considered past due based on policy payment terms. That allowance is determined based on periodic evaluations of aged receivables, management's experience and current economic conditions. Insurance receivables and any related allowance are written off after collection efforts are exhausted or a negotiated settlement is reached.
	Property and casualty contracts that are retrospectively rated contain provisions that result in an adjustment to the initial policy premium depending on the contract provisions and loss experience of the insured during the experience period. For such contracts, the Company estimates the amount of ultimate premiums that the Company may earn upon completion of the experience period and recognizes either an asset or a liability for the difference between the initial policy premium and the estimated ultimate premium. The Company adjusts such estimated ultimate premium amounts during the course of the experience period based on actual results to date. The resulting adjustment is recorded as either a reduction of or an increase to the earned premiums for the period.
Claim and claim adjustment expense reserves	Claim and claim adjustment expense reserves: Claim and claim adjustment expense reserves, except reserves for structured settlements not associated with asbestos and environmental pollution (A&EP), workers' compensation lifetime claims and accident and health claims, are not discounted and are based on 1) case basis estimates for losses reported on direct business, adjusted in the aggregate for ultimate loss expectations; 2) estimates of incurred but not reported (IBNR) losses; 3) estimates of losses on assumed reinsurance; 4) estimates of future expenses to be incurred in the settlement of claims; 5) estimates of salvage and subrogation recoveries and 6) estimates of amounts due from insureds related to losses under high deductible policies. Management considers current conditions and trends as well as past Company and industry experience in establishing these estimates. The effects of inflation, which can be significant, are implicitly considered in the reserving process and are part of the recorded reserve balance. Ceded claim and claim adjustment expense reserves are reported as a component of Reinsurance receivables on the Consolidated Balance Sheets.
	Claim and claim adjustment expense reserves are presented net of anticipated amounts due from insureds related to losses under deductible policies of $1.4 billion and $1.3 billion as of December 31, 2014 and 2013. A significant portion of these amounts are supported by collateral. The Company has an allowance for uncollectible deductible amounts, which is presented as a component of the allowance for doubtful accounts included in Insurance receivables on the Consolidated Balance Sheets.
	Structured settlements have been negotiated for certain property and casualty insurance claims. Structured settlements are agreements to provide fixed periodic payments to claimants. The Company's obligations for structured settlements not funded by annuities are included in claim and claim adjustment expense reserves and carried at present values determined using interest rates ranging from 5.5% to 8.0% at December 31, 2014 and 7.1% to 9.7% at December 31, 2013. At December 31, 2014 and 2013, the discounted reserves for unfunded structured settlements were $582 million and $580 million, net of discount of $924 million and $969 million.
	Workers' compensation lifetime claim reserves are calculated using mortality assumptions determined through statutory regulation and economic factors. Accident and health claim reserves are calculated using mortality and morbidity assumptions based on Company and industry experience. Workers' compensation lifetime claim reserves and accident and health claim reserves are discounted at interest rates ranging from 3.5% to 6.8% at December 31, 2014 and 3.0% to 6.8% at December 31, 2013. At December 31, 2014 and 2013, such discounted reserves totaled $2.5 billion and $2.4 billion, net of discount of $654 million and $617 million.
Future policy benefits reserves	Future policy benefits reserves: Reserves for long term care policies and payout annuity contracts are computed using the net level premium method, which incorporates actuarial assumptions as to morbidity, persistency, discount rate and expenses. Expense assumptions primarily relate to claim adjudication. Actuarial assumptions generally vary by plan, age at issue and policy duration. The initial assumptions are determined at issuance, include a margin for adverse deviation and are locked in throughout the life of the contract unless a premium deficiency develops. If a premium deficiency emerges, the assumptions are unlocked and deferred acquisition costs, if any, and the future policy benefit reserves are adjusted. Interest rates for long term care products range from 4.5% to 7.9% at December 31, 2014 and 2013. Interest rates for payout annuity contracts ranged from 5.0% to 8.7% at December 31, 2013.
Policyholders' funds reserves							Policyholders' funds reserves: Policyholders' funds reserves on the Consolidated Balance Sheet as of December 31, 2013 primarily included reserves for investment contracts without life contingencies. For these contracts, policyholder liabilities are generally equal to the accumulated policy account values, which consist of an accumulation of deposit payments plus credited interest, less withdrawals and amounts assessed through the end of the period.
Guaranty fund and other insurance-related assessments	Guaranty fund and other insurance-related assessments: Liabilities for guaranty fund and other insurance-related assessments are accrued when an assessment is probable, when it can be reasonably estimated and when the event obligating the entity to pay an imposed or probable assessment has occurred. Liabilities for guaranty funds and other insurance-related assessments are not discounted and are included as part of Other liabilities on the Consolidated Balance Sheets. As of December 31, 2014 and 2013, the liability balances were $131 million and $143 million.
Reinsurance	Reinsurance: Reinsurance accounting allows for contractual cash flows to be reflected as premiums and losses. To qualify for reinsurance accounting, reinsurance agreements must include risk transfer. To meet risk transfer requirements, a reinsurance contract must include both insurance risk, consisting of underwriting and timing risk, and a reasonable possibility of a significant loss for the assuming entity.
	Reinsurance receivables related to paid losses are presented at unpaid balances. Reinsurance receivables related to unpaid losses are estimated in a manner consistent with claim and claim adjustment expense reserves or future policy benefits reserves. Reinsurance receivables are reported net of an allowance for uncollectible amounts on the Consolidated Balance Sheets. The cost of reinsurance is primarily accounted for over the life of the underlying reinsured policies using assumptions consistent with those used to account for the underlying policies or over the reinsurance contract period. The ceding of insurance does not discharge the primary liability of the Company.
	The Company has established an allowance for uncollectible reinsurance receivables which relates to both amounts already billed on ceded paid losses as well as ceded reserves that will be billed when losses are paid in the future. The allowance for uncollectible reinsurance receivables is estimated on the basis of periodic evaluations of balances due from reinsurers, reinsurer solvency, management's experience and current economic conditions. Reinsurer financial strength ratings are updated and reviewed on an annual basis or sooner if the Company becomes aware of significant changes related to a reinsurer. Because billed receivables generally approximate 5% or less of total reinsurance receivables, the age of the reinsurance receivables related to paid losses is not a significant input into the allowance analysis. Changes in the allowance for uncollectible reinsurance receivables are presented as a component of Insurance claims and policyholders' benefits on the Consolidated Statements of Operations.
	Amounts are considered past due based on the reinsurance contract terms. Reinsurance receivables related to paid losses and any related allowance are written off after collection efforts have been exhausted or a negotiated settlement is reached with the reinsurer. Reinsurance receivables related to paid losses from insolvent insurers are written off when the settlement due from the estate can be reasonably estimated. At the time reinsurance receivables related to paid losses are written off, any required adjustment to reinsurance receivables related to unpaid losses is recorded as a component of Insurance claims and policyholders' benefits on the Consolidated Statements of Operations.
	Reinsurance contracts that do not effectively transfer the economic risk of loss on the underlying policies are recorded using the deposit method of accounting, which requires that premium paid or received by the ceding company or assuming company be accounted for as a deposit asset or liability. The Company had $3 million recorded as deposit assets at December 31, 2014 and 2013, and $9 million and $130 million recorded as deposit liabilities at December 31, 2014 and 2013. Income on reinsurance contracts accounted for under the deposit method is recognized using an effective yield based on the anticipated timing of payments and the remaining life of the contract. When the anticipated timing of payments changes, the effective yield is recalculated to reflect actual payments to date and the estimated timing of future payments. The deposit asset or liability is adjusted to the amount that would have existed had the new effective yield been applied since the inception of the contract.
	A loss portfolio transfer is a retroactive reinsurance contract. If the cumulative claim and allocated claim adjustment expenses ceded under a loss portfolio transfer exceed the consideration paid, the resulting gain from such excess is deferred and amortized into earnings in future periods in proportion to actual recoveries under the loss portfolio transfer. In the period in which an excess arises, a portion of the deferred gain is cumulatively recognized in earnings as if the revised estimate was available at the inception date of the loss portfolio transfer.
Deferred acquisition costs	Deferred acquisition costs: Acquisition costs include commissions, premium taxes and certain underwriting and policy issuance costs which are incremental direct costs of successful contract acquisitions. Deferred acquisition costs related to long term care contracts issued prior to January 1, 2004 include costs which vary with and are primarily related to the acquisition of business.
	Acquisition costs related to property and casualty business are deferred and amortized ratably over the period the related premiums are earned.
	Deferred acquisition costs related to long term care contracts are amortized over the premium-paying period of the related policies using assumptions consistent with those used for computing future policy benefit reserves for such contracts. Assumptions are made at the date of policy issuance or acquisition and are consistently applied during the lives of the contracts. Deviations from estimated experience are included in results of operations when they occur. For these contracts, the amortization period is typically the estimated life of the policy. At December 31, 2014 and 2013, Deferred acquisition costs were presented net of Shadow Adjustments, as defined later in this note, of $314 million and $342 million.
	The Company evaluates deferred acquisition costs for recoverability. Anticipated investment income is considered in the determination of the recoverability of deferred acquisition costs. Adjustments, if necessary, are recorded in current period results of operations.
	Deferred acquisition costs are presented net of ceding commissions and other ceded acquisition costs. Unamortized deferred acquisition costs relating to contracts that have been substantially changed by a modification in benefits, features, rights or coverages that were not anticipated in the original contract are not deferred and are included as a charge to operations in the period during which the contract modification occurred.
Investments in life settlement contracts and related revenue recognition	Investments in life settlement contracts and related revenue recognition: Prior to 2002, the Company purchased investments in life settlement contracts. A life settlement contract is a contract between the owner of a life insurance policy (the policy owner) and a third-party investor (investor). Under a life settlement contract, the Company obtains the ownership and beneficiary rights of an underlying life insurance policy.
	The Company accounts for its investments in life settlement contracts using the fair value method. Under the fair value method, each life settlement contract is carried at its fair value at the end of each reporting period. The change in fair value, life insurance proceeds received and periodic maintenance costs, such as premiums, necessary to keep the underlying policy in force, are recorded in Other revenues on the Consolidated Statements of Operations.
	The fair value of the Company's investments in life settlement contracts were $82 million and $88 million at December 31, 2014 and 2013, and are included in Other assets on the Consolidated Balance Sheets. The cash receipts and payments related to life settlement contracts are included in Cash flows from operating activities on the Consolidated Statements of Cash Flows.
	The following table details the values for life settlement contracts. The determination of fair value is discussed in Note D to the Consolidated Financial Statements.
	December 31, 2014	Number of Life Settlement Contracts	Fair Value of Life Settlement Contracts		Face Amount of Life Insurance Policies
			(In millions)		(In millions)
	Estimated maturity during:
	2015	60	$	11	$	37
	2016	60	10		33
	2017	50	9		30
	2018	50	7		26
	2019	50	6		26
	Thereafter	318	39		187
	Total	588	$	82	$	339
	The Company uses an actuarial model to estimate the aggregate face amount of life insurance that is expected to mature in each future year and the corresponding fair value. This model projects the likelihood of the insured's death for each inforce policy based upon the Company's estimated mortality rates, which may vary due to the relatively small size of the portfolio of life settlement contracts. The number of life settlement contracts presented in the table above is based upon the average face amount of inforce policies estimated to mature in each future year.
	The increase (decrease) in fair value recognized for the years ended December 31, 2014, 2013 and 2012 on contracts still held at each respective period-end was $8 million, $(2) million and $11 million. The gains recognized during the years ended December 31, 2014, 2013 and 2012 on contracts that settled were $25 million, $15 million and $42 million.
Separate Account Business							Separate Account Business: Separate account assets and liabilities on the Consolidated Balance Sheet as of December 31, 2013 represented contract holder funds related to investment and annuity products for which the policyholder assumes substantially all the risk and reward. The assets were segregated into accounts with specific underlying investment objectives and are legally segregated from the Company. All assets of the separate account business were carried at fair value with an equal amount recorded for separate account liabilities.
Investments	Investments
	The Company classifies its fixed maturity securities and its equity securities as either available-for-sale or trading, and as such, they are carried at fair value. Changes in fair value of trading securities are reported within Net investment income on the Consolidated Statements of Operations. Changes in fair value related to available-for-sale securities are reported as a component of Other comprehensive income. The cost of fixed maturity securities classified as available-for-sale is adjusted for amortization of premiums and accretion of discounts to maturity, which are included in Net investment income on the Consolidated Statements of Operations. Losses may be recognized within Net realized investment gains (losses) on the Consolidated Statements of Operations when a decline in value is determined by the Company to be other-than-temporary.
	To the extent that unrealized gains on fixed income securities supporting long term care products and payout annuity contracts would result in a premium deficiency if those gains were 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 (Shadow Adjustments). Shadow Adjustments, net of tax, increased $756 million and decreased $979 million for the years ended December 31, 2014 and 2013. At December 31, 2014 and 2013, net unrealized gains on investments included in Accumulated other comprehensive income (AOCI) were correspondingly reduced by $1,288 million and $532 million.
	For asset-backed securities included in fixed maturity securities, the Company recognizes income using an effective yield based on anticipated prepayments and the estimated economic life of the securities. When estimates of prepayments change, the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The amortized cost of high credit quality fixed rate securities is adjusted to the amount that would have existed had the new effective yield been applied since the acquisition of the securities. Such adjustments are reflected in Net investment income on the Consolidated Statements of Operations. Interest income on lower rated and variable rate securities is determined using the prospective yield method.
	The Company's carrying value of investments in limited partnerships is its share of the net asset value of each partnership, as determined by the General Partner. Certain partnerships for which results are not available on a timely basis are reported on a lag, primarily three months or less. Changes in net asset values are accounted for under the equity method and recorded within Net investment income on the Consolidated Statements of Operations.
	Mortgage loans are commercial in nature, are carried at unpaid principal balance, net of unamortized fees and any valuation allowance, and are recorded once funded. Mortgage loans are considered to be impaired loans when it is probable that contractual principal and interest payments will not be collected. A valuation allowance is established for impaired loans to the extent that the present value of expected future cash flows discounted at the loan's original effective interest rate is less than the carrying value of the loan. Interest income from mortgage loans is recognized on an accrual basis using the effective yield method. Accrual of income is generally suspended for mortgage loans that are impaired and collection of principal and interest payments is unlikely. Mortgage loans are considered past due when full principal or interest payments have not been received according to contractual terms.
	Other invested assets are carried at fair value and include overseas deposits and certain derivative securities. Overseas deposits are primarily short-term government securities, agency securities and corporate bonds held in trusts that are managed by Lloyd's. These funds are required of Lloyd's syndicates to protect policyholders in overseas markets and may be denominated in local currency.
	Short term investments are carried at fair value, with the exception of cash accounts earning interest, which are carried at cost and approximate fair value. Changes in fair value are reported as a component of Other comprehensive income.
	Purchases and sales of all securities are recorded on the trade date, except for private placement debt securities, including bank loan participations, which are recorded once funded. Realized investment gains and losses are determined on the basis of the cost or amortized cost of the specific securities sold.
Variable Interest Entities	In the normal course of investing activities, the Company enters into relationships with variable interest entities (VIEs), primarily as a passive investor in certain limited partnerships and asset-backed securities issued by third-party VIEs. The Company is not the primary beneficiary of these VIEs, and therefore does not consolidate them. The Company determines whether it is the primary beneficiary of a VIE based on a qualitative assessment of the entity’s purpose, the nature of its operations, its capital structure, its contractual terms and the Company’s relative exposure to the related risks of the VIE. The Company’s maximum exposure to loss with respect to these investments is limited to the investment carrying values included in the Company’s Consolidated Balance Sheets and any unfunded commitments.
Impairments, Other Than Temporary	A security is impaired if the fair value of the security is less than its cost adjusted for accretion, amortization and previously recorded other-than-temporary impairment (OTTI) losses, otherwise defined as an unrealized loss. When a security is impaired, the impairment is evaluated to determine whether it is temporary or other-than-temporary.
	Significant judgment is required in the determination of whether an OTTI loss has occurred for a security. The Company follows a consistent and systematic process for determining and recording an OTTI loss. The Company has established a committee responsible for the OTTI process. This committee, referred to as the Impairment Committee, is made up of three officers appointed by the Company’s Chief Financial Officer. The Impairment Committee is responsible for evaluating all securities in an unrealized loss position on at least a quarterly basis.
	The Impairment Committee’s assessment of whether an OTTI loss has occurred incorporates both quantitative and qualitative information. Fixed maturity securities that the Company intends to sell, or it more likely than not will be required to sell before recovery of amortized cost, are considered to be other-than-temporarily impaired and the entire difference between the amortized cost basis and fair value of the security is recognized as an OTTI loss in earnings. The remaining fixed maturity securities in an unrealized loss position are evaluated to determine if a credit loss exists. The factors considered by the Impairment Committee include (a) the financial condition and near term prospects of the issuer, (b) whether the debtor is current on interest and principal payments, (c) credit ratings of the securities and (d) general market conditions and industry or sector specific outlook. The Company also considers results and analysis of cash flow modeling for asset-backed securities, and when appropriate, other fixed maturity securities. The focus of the analysis for asset-backed securities is on assessing the sufficiency and quality of underlying collateral and timing of cash flows based on scenario tests. If the present value of the modeled expected cash flows equals or exceeds the amortized cost of a security, no credit loss is judged to exist and the asset-backed security is deemed to be temporarily impaired. If the present value of the expected cash flows is less than amortized cost, the security is judged to be other-than-temporarily impaired for credit reasons and that shortfall, referred to as the credit component, is recognized as an OTTI loss in earnings. The difference between the adjusted amortized cost basis and fair value, referred to as the non-credit component, is recognized as OTTI in Other comprehensive income. In subsequent reporting periods, a change in intent to sell or further credit impairment on a security whose fair value has not deteriorated will cause the non-credit component originally recorded as OTTI in Other comprehensive income to be recognized as an OTTI loss in earnings.
	The Company performs the discounted cash flow analysis using stressed scenarios to determine future expectations regarding recoverability. Significant assumptions enter into these cash flow projections including delinquency rates, probable risk of default, loss severity upon a default, over collateralization and interest coverage triggers and credit support from lower level tranches.
	The Company applies the same impairment model as described above for the majority of non-redeemable preferred stock securities on the basis that these securities possess characteristics similar to debt securities and that the issuers maintain their ability to pay dividends. For all other equity securities, in determining whether the security is other-than-temporarily impaired, the Impairment Committee considers a number of factors including, but not limited to: (a) the length of time and the extent to which the fair value has been less than amortized cost, (b) the financial condition and near term prospects of the issuer, (c) the intent and ability of the Company to retain its investment for a period of time sufficient to allow for an anticipated recovery in value and (d) general market conditions and industry or sector specific outlook.
Income Taxes	Income Taxes
	The Company and its eligible subsidiaries (CNA Tax Group) are included in the consolidated federal income tax return of Loews and its eligible subsidiaries. The Company accounts for income taxes under the asset and liability method. Under the asset and liability method, deferred income taxes are recognized for temporary differences between the financial statement and tax return bases of assets and liabilities, based on enacted tax rates and other provisions of the tax law. The effect of a change in tax laws or rates on deferred tax assets and liabilities is recognized in income in the period in which such change is enacted. Future tax benefits are recognized to the extent that realization of such benefits is more likely than not, and a valuation allowance is established for any portion of a deferred tax asset that management believes will not be realized.
Pension and Postretirement Benefits	Pension and Postretirement Benefits
	The Company recognizes the overfunded or underfunded status of its defined benefit plans in Other assets or Other liabilities on the Consolidated Balance Sheets. Changes in funded status related to prior service costs and credits and actuarial gains and losses are recognized in the year in which the changes occur through Other comprehensive income. Annual service cost, interest cost, expected return on plan assets, amortization of prior service costs and credits and amortization of actuarial gains and losses are recognized in the Consolidated Statements of Operations. The vested benefit obligation for the CNA Retirement Plan is determined based on the employees’ expected date of separation or retirement.
Stock-Based Compensation	Stock-Based Compensation
	The Company records compensation expense using the fair value method for all awards it grants, modifies or cancels primarily on a straight-line basis over the requisite service period, generally three to four years.
Foreign Currency	Foreign Currency
	Foreign currency translation gains and losses are reflected in Stockholders' equity as a component of AOCI. The Company's foreign subsidiaries' balance sheet accounts are translated at the exchange rates in effect at each reporting date and income statement accounts are either translated at the exchange rate on the date of the transaction or at the average exchange rates. Foreign currency transaction gains (losses) of $(25) million, $2 million and $12 million were included in determining net income (loss) for the years ended December 31, 2014, 2013 and 2012.
Property and Equipment	Property and Equipment
	Property and equipment are carried at cost less accumulated depreciation. Depreciation is based on the estimated useful lives of the various classes of property and equipment and is determined principally on the straight-line method. Furniture and fixtures are depreciated over seven years. Office equipment is depreciated over five years. The estimated lives for data processing equipment and software range from three to five years. Leasehold improvements are depreciated over the corresponding lease terms not to exceed the underlying asset life. The Company's owned buildings, and related capital improvements, are depreciated over periods not to exceed fifty years.
Goodwill	Goodwill
	Goodwill represents the excess of purchase price over the fair value of the net assets of acquired entities and businesses. Goodwill in the International segment may change from period to period as a result of foreign currency translation.
	Goodwill is tested for impairment annually or when certain triggering events require such tests. As a result of reviews completed for the year ended December 31, 2014, the Company determined that the estimated fair value of the reporting units were in excess of their carrying value including Goodwill. Changes in future periods in assumptions about the level of economic capital, business growth, earnings projections or the weighted average cost of capital could result in a goodwill impairment
Other Intangible Assets	Other Intangible Assets
	Other intangible assets are reported within Other assets. Finite-lived intangible assets are amortized over their estimated useful lives. Indefinite-lived other intangible assets are tested for impairment annually or when certain triggering events require such tests.
Earnings (Loss) Per Share Data	Earnings (Loss) Per Share Data
	Earnings (loss) per share is based on 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 years ended December 31, 2014, 2013 and 2012, approximately 675 thousand, 552 thousand and 417 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 170 thousand, 111 thousand and 730 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.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Life Settlement Contracts) (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Life settlement contracts	The following table details the values for life settlement contracts. The determination of fair value is discussed in Note D to the Consolidated Financial Statements.
	December 31, 2014	Number of Life Settlement Contracts	Fair Value of Life Settlement Contracts		Face Amount of Life Insurance Policies
			(In millions)		(In millions)
	Estimated maturity during:
	2015	60	$	11	$	37
	2016	60	10		33
	2017	50	9		30
	2018	50	7		26
	2019	50	6		26
	Thereafter	318	39		187
	Total	588	$	82	$	339

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Investments [Abstract]
Net investment income	Net Investment Income
	Years ended December 31
	(In millions)	2014			2013			2012
	Fixed maturity securities	$	1,803		$	1,827		$	1,846
	Short term investments	3			3			5
	Limited partnership investments	263			451			251
	Equity securities	12			12			12
	Mortgage loans	31			23			17
	Trading portfolio	10			17			24
	Other	3			2			7
	Gross investment income	2,125			2,335			2,162
	Investment expense	(58		)	(53		)	(52		)
	Net investment income	$	2,067		$	2,282		$	2,110
Net realized investment gains (losses)	Net Realized Investment Gains (Losses)
	Years ended December 31
	(In millions)	2014			2013			2012
	Net realized investment gains (losses):
	Fixed maturity securities:
	Gross realized gains	$	170		$	185		$	222
	Gross realized losses	(129		)	(144		)	(145		)
	Net realized investment gains (losses) on fixed maturity securities	41			41			77
	Equity securities:
	Gross realized gains	8			13			19
	Gross realized losses	(7		)	(35		)	(42		)
	Net realized investment gains (losses) on equity securities	1			(22		)	(23		)
	Derivatives	(1		)	(9		)	(2		)
	Short term investments and other	16			10			2
	Net realized investment gains (losses)	$	57		$	20		$	54
Net change in unrealized gains (losses) on investments	Net Change in Unrealized Gains
	Years ended December 31
	(In millions)	2014			2013			2012
	Net change in unrealized gains on investments:
	Fixed maturity securities	$	1,511		$	(2,541	)	$	1,871
	Equity securities	6			(15		)	5
	Other	—			—			(1		)
	Total net change in unrealized gains on investments	$	1,517		$	(2,556	)	$	1,875
Components Of Net Other Than Temporary Impairment Losses Recognized In Earnings By Asset Type [Table Text Block]	The components of OTTI losses recognized in earnings by asset type are summarized in the following table.
	Years ended December 31
	(In millions)	2014			2013			2012
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	18		$	20		$	25
	States, municipalities and political subdivisions	46			—			34
	Asset-backed:
	Residential mortgage-backed	5			19			48
	Other asset-backed	1			2			—
	Total asset-backed	6			21			48
	U.S. Treasury and obligations of government-sponsored enterprises	—			—			1
	Total fixed maturity securities available-for-sale	70			41			108
	Equity securities available-for-sale:
	Common stock	7			8			6
	Preferred stock	—			26			36
	Total equity securities available-for-sale	7			34			42
	Short term investments	—			1			—
	OTTI losses recognized in earnings	$	77		$	76		$	150
Summary of fixed maturity and equity securities	Summary of Fixed Maturity and Equity Securities
	December 31, 2014	Cost or			Gross			Gross			Estimated		Unrealized
		Amortized			Unrealized			Unrealized			Fair		OTTI
	(In millions)	Cost			Gains			Losses			Value		Losses (Gains)
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	17,210		$	1,721		$	61		$	18,870	$	—
	States, municipalities and political subdivisions	11,285			1,463			8			12,740		—
	Asset-backed:
	Residential mortgage-backed	5,028			218			13			5,233		(53		)
	Commercial mortgage-backed	2,056			93			5			2,144		(2		)
	Other asset-backed	1,234			11			10			1,235		—
	Total asset-backed	8,318			322			28			8,612		(55		)
	U.S. Treasury and obligations of government-sponsored enterprises	26			5			—			31		—
	Foreign government	438			16			—			454		—
	Redeemable preferred stock	39			3			—			42		—
	Total fixed maturity securities available-for-sale	37,316			3,530			97			40,749		$	(55	)
	Total fixed maturity securities trading	19									19
	Equity securities available-for-sale:
	Common stock	38			9			—			47
	Preferred stock	172			5			2			175
	Total equity securities available-for-sale	210			14			2			222
	Total	$	37,545		$	3,544		$	99		$	40,990
	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
	December 31, 2014	Estimated			Gross			Estimated			Gross		Estimated			Gross
		Fair Value			Unrealized			Fair Value			Unrealized		Fair Value			Unrealized
	(In millions)				Losses						Losses					Losses
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	1,330		$	46		$	277		$	15	$	1,607		$	61
	States, municipalities and political subdivisions	335			5			127			3		462			8
	Asset-backed:
	Residential mortgage-backed	293			5			189			8		482			13
	Commercial mortgage-backed	264			2			99			3		363			5
	Other asset-backed	607			10			7			—		614			10
	Total asset-backed	1,164			17			295			11		1,459			28
	U.S. Treasury and obligations of government-sponsored enterprises	3			—			4			—		7			—
	Foreign government	3			—			3			—		6			—
	Redeemable preferred stock	3			—			—			—		3			—
	Total fixed maturity securities available-for-sale	2,838			68			706			29		3,544			97
	Equity securities available-for-sale:
	Preferred stock	17			2			1			—		18			2
	Total	$	2,855		$	70		$	707		$	29	$	3,562		$	99
		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 years ended December 31, 2014, 2013 and 2012 related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held at December 31, 2014, 2013 and 2012 for which a portion of an OTTI loss was recognized in Other comprehensive income.
	Years ended December 31
	(In millions)	2014			2013			2012
	Beginning balance of credit losses on fixed maturity securities	$	74		$	95		$	92
	Additional credit losses for securities for which an OTTI loss was previously recognized	—			2			23
	Credit losses for securities for which an OTTI loss was not previously recognized	—			—			2
	Reductions for securities sold during the period	(9		)	(23		)	(14		)
	Reductions for securities the Company intends to sell or more likely than not will be required to sell	(3		)	—			(8		)
	Ending balance of credit losses on fixed maturity securities	$	62		$	74		$	95
Contractual maturity	Contractual Maturity
	31-Dec	2014						2013
	(In millions)	Cost or			Estimated			Cost or			Estimated
		Amortized			Fair			Amortized			Fair
		Cost			Value			Cost			Value
	Due in one year or less	$	2,479		$	2,511		$	2,420		$	2,455
	Due after one year through five years	9,054			9,605			9,496			10,068
	Due after five years through ten years	12,055			12,584			11,667			11,954
	Due after ten years	13,728			16,049			15,692			16,720
	Total	$	37,316		$	40,749		$	39,275		$	41,197

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 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
	December 31, 2014	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Currency forwards	$	9	$	—	$	—
	Equity warrants	5		—		—
	Embedded derivative on funds withheld liability	184		—		(3		)
	Total			$	—	$	(3	)
	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)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Assets and liabilities measured at fair value on a recurring basis	Assets and liabilities measured at fair value on a recurring basis are summarized below.
	December 31, 2014									Total
										Assets/ (Liabilities)
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	32	$	18,695		$	162		$	18,889
	States, municipalities and political subdivisions	—		12,646			94			12,740
	Asset-backed:
	Residential mortgage-backed	—		5,044			189			5,233
	Commercial mortgage-backed	—		2,061			83			2,144
	Other asset-backed	—		580			655			1,235
	Total asset-backed	—		7,685			927			8,612
	U.S. Treasury and obligations of government-sponsored enterprises	28		3			—			31
	Foreign government	41		413			—			454
	Redeemable preferred stock	30		12			—			42
	Total fixed maturity securities	131		39,454			1,183			40,768
	Equity securities	145		61			16			222
	Other invested assets	—		41			—			41
	Short term investments	681		963			—			1,644
	Life settlement contracts, included in Other assets	—		—			82			82
	Total assets	$	957	$	40,519		$	1,281		$	42,757
	Liabilities
	Other liabilities	$	—	$	(3	)	$	—		$	(3	)
	Total liabilities	$	—	$	(3	)	$	—		$	(3	)
	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 years ended December 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 December 31, 2014 recognized in net income (loss)*
	(In millions)	January 1,																	Level 3		of Level 3			December 31,
		2014																						2014
	Fixed maturity securities:
	Corporate and other bonds	$	204	$	2		$	(1	)	$	33		$	(23	)	$	(16	)	$	18	$	(55	)	$	162	$	—
	States, municipalities and political subdivisions	71		1			4			14			(10		)	—			14		—			94		—
	Asset-backed:
	Residential mortgage-backed	331		(21		)	61			94			(174		)	(72		)	32		(62		)	189		—
	Commercial mortgage-backed	151		7			(6		)	28			(60		)	(29		)	43		(51		)	83		—
	Other asset-backed	446		2			(6		)	488			(111		)	(117		)	—		(47		)	655		(1		)
	Total asset-backed	928		(12		)	49			610			(345		)	(218		)	75		(160		)	927		(1		)
	Total fixed maturity securities	1,203		(9		)	52			657			(378		)	(234		)	107		(215		)	1,183		(1		)
	Equity securities	11		3			(6		)	16			(8		)	—			—		—			16		—
	Life settlement contracts	88		33			—			—			—			(39		)	—		—			82		8
	Separate account business	1		—			—			—			—			—			—		(1		)	—		—
	Total	$	1,303	$	27		$	46		$	673		$	(386	)	$	(273	)	$	107	$	(216	)	$	1,281	$	7
	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 December 31, 2013 recognized in net income (loss)*
	(In millions)	January 1,																	Level 3		of Level 3			December 31,
		2013																						2013
	Fixed maturity securities:
	Corporate and other bonds	$	219	$	3		$	—		$	142		$	(116	)	$	(44	)	$	51	$	(51	)	$	204	$	(2	)
	States, municipalities and political subdivisions	96		(2		)	4			122			(79		)	(61		)	18		(27		)	71		—
	Asset-backed:
	Residential mortgage-backed	413		4			(14		)	116			(10		)	(75		)	4		(107		)	331		(3		)
	Commercial mortgage-backed	129		—			11			107			(3		)	(11		)	21		(103		)	151		—
	Other asset-backed	368		5			(4		)	314			(197		)	(35		)	—		(5		)	446		(2		)
	Total asset-backed	910		9			(7		)	537			(210		)	(121		)	25		(215		)	928		(5		)
	Redeemable preferred stock	26		(1		)	—			—			—			(25		)	—		—			—		—
	Total fixed maturity securities	1,251		9			(3		)	801			(405		)	(251		)	94		(293		)	1,203		(7		)
	Equity securities	34		(27		)	3			2			—			—			—		(1		)	11		(27		)
	Other invested assets, including derivatives, net	—		—			—			—			(1		)	1			—		—			—		—
	Short term investments	6		—			—			—			(6		)	—			—		—			—		—
	Life settlement contracts	100		13			—			—			—			(25		)	—		—			88		(2		)
	Separate account business	2		—			—			1			(2		)	—			—		—			1		—
	Total	$	1,393	$	(5	)	$	—		$	804		$	(414	)	$	(275	)	$	94	$	(294	)	$	1,303	$	(36	)
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.
	31-Dec-14
	Assets	Fair Value		Valuation Technique(s)		Unobservable Input(s)	Range
	(In millions)						(Weighted Average)
	Fixed maturity securities	$	101	Discounted cash flow		Credit spread	2% - 13% (3%)
	Equity securities	16		Market approach		Private offering price	$12 - $4,391 per share ($600)
	Life settlement contracts	82		Discounted cash flow		Discount rate risk premium	9%
						Mortality assumption	55% - 1676% (163%)
	31-Dec-13
	Assets	Fair Value		Valuation Technique(s)		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 Consolidated Balance Sheets are listed in the tables below.
	December 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	$	1	$	—		$	—		$	1		$	1
	Mortgage loans	588		—			—			608			608
	Financial liabilities
	Long term debt	$	2,559	$	—		$	2,883		$	—		$	2,883
	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

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Reconcilliation between the Company's federal income tax (expense) benefit at statutory rates and the recorded income tax (expense) benefit	Tax Reconciliation
	Years ended December 31
	(In millions)	2014			2013			2012
	Income tax expense at statutory rates	$	(423	)	$	(447	)	$	(301	)
	Tax benefit from tax exempt income	119			97			84
	Foreign taxes and credits	(6		)	(1		)	(13		)
	Other tax expense	(9		)	(10		)	(9		)
	Income tax expense	$	(319	)	$	(361	)	$	(239	)
Current and deferred components of the Company's income tax (expense) benefit	Current and Deferred Taxes
	Years ended December 31
	(In millions)	2014			2013			2012
	Current tax expense	$	(318	)	$	(292	)	$	(94	)
	Deferred tax expense	(1		)	(69		)	(145		)
	Total income tax expense	$	(319	)	$	(361	)	$	(239	)
Significant components of the Company's deferred tax assets and liabilities	Components of Net Deferred Tax Asset
	31-Dec
	(In millions)	2014			2013
	Deferred Tax Assets:
	Insurance reserves:
	Property and casualty claim and claim adjustment expense reserves	$	265		$	289
	Unearned premium reserves	187			178
	Receivables	35			50
	Employee benefits	289			187
	Life settlement contracts	46			46
	Deferred retroactive reinsurance benefit	61			66
	Other assets	138			149
	Gross deferred tax assets	1,021			965
	Deferred Tax Liabilities:
	Investment valuation differences	50			68
	Deferred acquisition costs	226			232
	Net unrealized gains	489			383
	Other liabilities	65			62
	Gross deferred tax liabilities	830			745
	Net deferred tax asset	$	191		$	220

Claim_and_Claim_Adjustment_Exp1

Claim and Claim Adjustment Expense Reserves (Tables)	12 Months Ended
	Dec. 31, 2014
Claim and Claim Adjustment Expense Reserves [Abstract]
Reconciliation of claim and claim adjustment expense reserves	Reconciliation of Claim and Claim Adjustment Expense Reserves
	As of and for the years ended December 31
	(In millions)	2014			2013			2012
	Reserves, beginning of year:
	Gross	$	24,089		$	24,763		$	24,303
	Ceded	4,972			5,126			5,020
	Net reserves, beginning of year	19,117			19,637			19,283
	Change in net reserves due to acquisition (disposition) of subsidiaries	(13		)	—			291
	Net incurred claim and claim adjustment expenses:
	Provision for insured events of current year	5,043			5,114			5,273
	Decrease in provision for insured events of prior years	(36		)	(115		)	(182		)
	Amortization of discount	161			154			145
	Total net incurred (a)	5,168			5,153			5,236
	Net payments attributable to:
	Current year events	(945		)	(981		)	(988		)
	Prior year events	(4,355		)	(4,588		)	(4,280		)
	Total net payments	(5,300		)	(5,569		)	(5,268		)
	Foreign currency translation adjustment and other	(45		)	(104		)	95
	Net reserves, end of year	18,927			19,117			19,637
	Ceded reserves, end of year	4,344			4,972			5,126
	Gross reserves, end of year	$	23,271		$	24,089		$	24,763
	(a)	Total net incurred above does not agree to Insurance claims and policyholders' benefits as reflected on the Consolidated Statements of Operations due to amounts related to retroactive reinsurance deferred gain accounting, uncollectible reinsurance and loss deductible receivables, and benefit expenses related to future policy benefits and policyholders' funds, which are not reflected in the table above.
Net prior year claim and claim adjustment expense reserve development	Reserve Development
	Years ended December 31
	(In millions)	2014			2013			2012
	Property and casualty reserve development	$	(39	)	$	(115	)	$	(180	)
	Life reserve development in life company	3			—			(2		)
	Total	$	(36	)	$	(115	)	$	(182	)
Gross and net carried claim and claim adjustment expense reserves	Gross and Net Carried Claim and Claim Adjustment Expense Reserves
	December 31, 2014	Specialty			Commercial			International			Life &			Corporate			Total
	(In millions)										Group Non-Core			& Other Non-Core
	Gross Case Reserves	$	2,136		$	5,298		$	752		$	2,881		$	1,189		$	12,256
	Gross IBNR Reserves	4,093			4,216			689			302			1,715			11,015
	Total Gross Carried Claim and Claim Adjustment Expense Reserves	$	6,229		$	9,514		$	1,441		$	3,183		$	2,904		$	23,271
	Net Case Reserves	$	1,929		$	4,947		$	598		$	2,572		$	144		$	10,190
	Net IBNR Reserves	3,726			3,906			663			271			171			8,737
	Total Net Carried Claim and Claim Adjustment Expense Reserves	$	5,655		$	8,853		$	1,261		$	2,843		$	315		$	18,927
	December 31, 2013	Specialty			Commercial			International			Life &			Corporate			Total
	(In millions)										Group Non-Core			& Other Non-Core
	Gross Case Reserves	$	2,001		$	5,570		$	803		$	2,748		$	1,140		$	12,262
	Gross IBNR Reserves	4,057			4,521			772			310			2,167			11,827
	Total Gross Carried Claim and Claim Adjustment Expense Reserves	$	6,058		$	10,091		$	1,575		$	3,058		$	3,307		$	24,089
	Net Case Reserves	$	1,793		$	5,119		$	629		$	2,352		$	283		$	10,176
	Net IBNR Reserves	3,789			3,992			705			271			184			8,941
	Total Net Carried Claim and Claim Adjustment Expense Reserves	$	5,582		$	9,111		$	1,334		$	2,623		$	467		$	19,117
Net prior year development	Net Prior Year Development
	Year ended December 31, 2014
	(In millions)	Specialty			Commercial			International			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(136	)	$	176		$	(59	)	$	(2	)	$	(21	)
	Pretax (favorable) unfavorable premium development	(13		)	(20		)	2			(1		)	(32		)
	Total pretax (favorable) unfavorable net prior year development	$	(149	)	$	156		$	(57	)	$	(3	)	$	(53	)
	Year ended December 31, 2013
	(In millions)	Specialty			Commercial			International			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(196	)	$	122		$	(38	)	$	(6	)	$	(118	)
	Pretax (favorable) unfavorable premium development	(14		)	(8		)	(21		)	1			(42		)
	Total pretax (favorable) unfavorable net prior year development	$	(210	)	$	114		$	(59	)	$	(5	)	$	(160	)
	Year ended December 31, 2012
	(In millions)	Specialty			Commercial			International			Corporate			Total
											& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(93	)	$	(25	)	$	(74	)	$	(13	)	$	(205	)
	Pretax (favorable) unfavorable premium development	(14		)	(36		)	3			1			(46		)
	Total pretax (favorable) unfavorable net prior year development	$	(107	)	$	(61	)	$	(71	)	$	(12	)	$	(251	)
Net prior year claim and allocated claim adjustment expense reserve development for Specialty segment	The following table provides further detail of the net prior year claim and allocated claim adjustment expense reserve development (development) recorded for the Specialty segment for the years ended December 31, 2014, 2013 and 2012.
	Years ended December 31
	(In millions)	2014			2013			2012
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Medical Professional Liability	$	39		$	(27	)	$	(34	)
	Other Professional Liability and Management Liability	(87		)	(73		)	19
	Surety	(82		)	(74		)	(63		)
	Warranty	(2		)	(3		)	(5		)
	Other	(4		)	(19		)	(10		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(136	)	$	(196	)	$	(93	)
Net prior year claim and allocated claim adjustment expense reserve development for Commercial segment	The following table provides further detail of the development recorded for the Commercial segment for the years ended December 31, 2014, 2013 and 2012.
	Years ended December 31
	(In millions)	2014			2013			2012
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Commercial Auto	$	31		$	18		$	25
	General Liability	45			64			(66		)
	Workers' Compensation	139			91			15
	Property and Other	(39		)	(51		)	1
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	176		$	122		$	(25	)
Net prior year claim and allocated claim adjustment expense reserve development for International segment	The following table provides further detail of the development recorded for the International segment for the years ended December 31, 2014, 2013 and 2012.
	Years ended December 31
	(In millions)	2014			2013			2012
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Medical Professional Liability	$	(7	)	$	(7	)	$	1
	Other Professional Liability	(26		)	(30		)	(41		)
	Liability	(13		)	(8		)	(2		)
	Property & Marine	(14		)	13			(30		)
	Other	(9		)	(17		)	(2		)
	Commutations	10			11			—
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(59	)	$	(38	)	$	(74	)
Impact of loss portfolio transfer on the consolidated statement of operations	The following table displays the impact of the Loss Portfolio Transfer on the Consolidated Statements of Operations.
	Years ended December 31
	(In millions)	2014			2013			2012
	Net A&EP adverse development before consideration of LPT	$	—		$	363		$	261
	Provision for uncollectible third-party reinsurance on A&EP	—			140			—
	Additional amounts ceded under LPT	—			503			261
	Retroactive reinsurance benefit recognized	(13		)	(314		)	(261		)
	Pretax impact of unrecognized deferred retroactive reinsurance benefit	$	(13	)	$	189		$	—

Reinsurance_Tables

Reinsurance (Tables)	12 Months Ended
	Dec. 31, 2014
Reinsurance Disclosures [Abstract]
Components of Reinsurance Receivables	Components of Reinsurance Receivables
	31-Dec
	(In millions)	2014			2013
	Reinsurance receivables related to insurance reserves:
	Ceded claim and claim adjustment expenses	$	4,344		$	4,972
	Ceded future policy benefits	185			733
	Ceded policyholders' funds	—			35
	Reinsurance receivables related to paid losses	213			348
	Reinsurance receivables	4,742			6,088
	Allowance for uncollectible reinsurance	(48		)	(71		)
	Reinsurance receivables, net of allowance for uncollectible reinsurance	$	4,694		$	6,017
Components of Earned and Written Premiums	Components of Earned Premiums
	(In millions)	Direct			Assumed			Ceded		Net		Assumed/
												Net %
	2014 Earned Premiums
	Property and casualty	$	9,452		$	277		$	3,073	$	6,656	4.2	%
	Accident and health	508			48			—		556		8.6	%
	Total earned premiums	$	9,960		$	325		$	3,073	$	7,212	4.5	%
	2013 Earned Premiums
	Property and casualty	$	9,063		$	258		$	2,609	$	6,712	3.8	%
	Accident and health	511			48			—		559		8.6	%
	Total earned premiums	$	9,574		$	306		$	2,609	$	7,271	4.2	%
	2012 Earned Premiums
	Property and casualty	$	8,354		$	197		$	2,229	$	6,322	3.1	%
	Accident and health	512			47			—		559		8.4	%
	Total earned premiums	$	8,866		$	244		$	2,229	$	6,881	3.5	%
	Components of Written Premiums
	(In millions)	Direct			Assumed			Ceded		Net		Assumed/
												Net %
	2014 Written Premiums
	Property and casualty	$	9,283		$	276		$	3,024	$	6,535	4.2	%
	Accident and health	504			49			—		553		8.9	%
	Total written premiums	$	9,787		$	325		$	3,024	$	7,088	4.6	%
	2013 Written Premiums
	Property and casualty	$	9,103		$	249		$	2,556	$	6,796	3.7	%
	Accident and health	505			47			—		552		8.5	%
	Total written premiums	$	9,608		$	296		$	2,556	$	7,348	4	%
	2012 Written Premiums
	Property and casualty	$	8,467		$	169		$	2,225	$	6,411	2.6	%
	Accident and health	506			47			—		553		8.5	%
	Total written premiums	$	8,973		$	216		$	2,225	$	6,964	3.1	%

Debt_Tables

Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Schedule of debt instruments
	31-Dec
	(In millions)	2014			2013
	Short term debt:
	Senior notes of CNAF, 5.850%, face amount of $549, due December 15, 2014	$	—		$	549
	Long term debt:
	Senior notes of CNAF:
	6.500%, face amount of $350, due August 15, 2016	349			349
	6.950%, face amount of $150, due January 15, 2018	150			149
	7.350%, face amount of $350, due November 15, 2019	348			348
	5.875%, face amount of $500, due August 15, 2020	497			497
	5.750%, face amount of $400, due August 15, 2021	397			397
	3.950%, face amount of $550, due May 15, 2024	547			—
	Debenture of CNAF, 7.250%, face amount of $243, due November 15, 2023	241			241
	Subordinated variable rate debt of Hardy, face amount of $30, due September 15, 2036	30			30
	Total long term debt	2,559			2,011
	Total debt	$	2,559		$	2,560
Maturity of debt	Maturity of Debt
	(In millions)
	2015	$	—
	2016	350
	2017	—
	2018	150
	2019	350
	Thereafter	1,723
	Less discount	(14		)
	Total	$	2,559

Benefit_Plans_Tables

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Funded status	Funded Status
		Pension Benefits								Postretirement Benefits
	(In millions)	2014				2013				2014			2013
	Benefit obligation at January 1	$	2,943			$	3,271			$	40		$	47
	Changes in benefit obligation:
	Service cost	9				12				—			1
	Interest cost	132				121				1			1
	Participants' contributions	—				—				5			5
	Plan amendments	(3		)		—				(7		)	—
	Actuarial (gain) loss	367				(289		)		1			(3		)
	Benefits paid	(165		)		(165		)		(11		)	(12		)
	Settlements	(257		)		(8		)		—			—
	Foreign currency translation and other	(7		)		1				—			1
	Benefit obligation at December 31	3,019				2,943				29			40
	Fair value of plan assets at January 1	2,656				2,425				—			—
	Change in plan assets:
	Actual return on plan assets	216				311				—			—
	Company contributions	12				92				6			7
	Participants' contributions	—				—				5			5
	Benefits paid	(165		)		(165		)		(11		)	(12		)
	Settlements	(257		)		(8		)		—			—
	Foreign currency translation and other	(6		)		1				—			—
	Fair value of plan assets at December 31	2,456				2,656				—			—
	Funded status	$	(563	)		$	(287	)		$	(29	)	$	(40	)
	Amounts recognized on the Consolidated Balance Sheets at December 31:
	Other assets	$	9			$	9			$	—		$	—
	Other liabilities	(572		)		(296		)		(29		)	(40		)
	Net amount recognized	$	(563	)		$	(287	)		$	(29	)	$	(40	)
	Amounts recognized in Accumulated other comprehensive income, not yet recognized in net periodic cost (benefit):
	Prior service credit	$	—			$	—			$	(9	)	$	(98	)
	Net actuarial loss	974				745				8			8
	Net amount recognized	$	974			$	745			$	(1	)	$	(90	)
Components of net periodic cost (benefit)	Net Periodic Cost (Benefit)
	Years ended December 31
	(In millions)	2014				2013				2012
	Pension cost (benefit)
	Service cost	$	9			$	12			$	12
	Interest cost on projected benefit obligation	132				121				135
	Expected return on plan assets	(191		)		(181		)		(171		)
	Amortization of net actuarial loss	25				47				39
	Settlement loss	84				3				—
	Net periodic pension cost (benefit)	$	59			$	2			$	15
	Postretirement cost (benefit)
	Service cost	$	—			$	1			$	—
	Interest cost on projected benefit obligation	1				1				2
	Amortization of prior service credit	(10		)		(18		)		(18		)
	Amortization of net actuarial loss	1				2				1
	Curtailment gain	(86		)		—				—
	Net periodic postretirement cost (benefit)	$	(94	)		$	(14	)		$	(15	)
Schedule of amounts recognized in Other comprehensive income	The amounts recognized in Other comprehensive income are presented in the following table.
	Years ended December 31
	(In millions)	2014				2013				2012
	Pension and postretirement benefits
	Amounts arising during the period	$	(337	)		$	422			$	(195	)
	Curtailment and other	(81		)		—				—
	Settlement	84				—				—
	Reclassification adjustment relating to prior service credit	(10		)		(18		)		(18		)
	Reclassification adjustment relating to actuarial loss	26				49				40
	Total increase (decrease) in Other comprehensive income	$	(318	)		$	453			$	(173	)
Schedule of estimated amounts to be recognized from Accumulated other comprehensive income into net periodic cost (benefit) during next fiscal year	The table below presents the estimated amounts to be recognized from AOCI into net periodic cost (benefit) during 2015.
	(In millions)		Pension				Postretirement Benefits
			Benefits
	Amortization of prior service credit		$	—			$	(2	)
	Amortization of net actuarial loss		38				1
	Total estimated amounts to be recognized		$	38			$	(1	)
Actuarial assumptions for benefit obligations and for net cost or benefit	Actuarial assumptions used for the CNA Retirement Plan and CNA Health and Group Benefits Program to determine benefit obligations are set forth in the following table.
	Actuarial Assumptions for Benefit Obligations
	31-Dec	2014			2013
	Pension benefits
	Discount rate	3.85	%		4.65	%
	Expected long term rate of return	7.5			7.5
	Rate of compensation increases	3.92			3.99
	Postretirement benefits
	Discount rate	2.5	%		3.6	%
	Actuarial assumptions used for the CNA Retirement Plan and CNA Health and Group Benefits Program to determine net cost or benefit are set forth in the following table.
	Actuarial Assumptions for Net Cost or Benefit
	Years ended December 31	2014			2013			2012
	Pension benefits
	Discount rate	4.65	%		3.8	%		4.6	%
	Expected long term rate of return	7.5			7.75			8
	Rate of compensation increases	3.99			4.066			4.125
	Postretirement benefits
	Discount rate	3.600%/3.100%			2.8	%		3.75	%
Fair value of plan assets measured on a recurring basis	Pension plan assets measured at fair value on a recurring basis as well as cash are summarized below.
	December 31, 2014
	(In millions)		Level 1				Level 2				Level 3			Total Assets
														at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds		$	—			$	463			$	15		$	478
	States, municipalities and political subdivisions		—				80				—			80
	Asset-backed:
	Residential mortgage-backed		—				123				—			123
	Commercial mortgage-backed		—				75				—			75
	Other asset-backed		—				12				—			12
	Total asset-backed		—				210				—			210
	U.S. Treasury and obligations of government-sponsored enterprises		25				—				—			25
	Total fixed maturity securities		25				753				15			793
	Equity securities		389				118				—			507
	Derivative financial instruments		1				—				—			1
	Short term investments		33				101				—			134
	Limited partnerships:
	Hedge funds		—				562				303			865
	Private equity		—				—				113			113
	Total limited partnerships		—				562				416			978
	Other assets		—				30				—			30
	Cash		13				—				—			13
	Total assets		$	461			$	1,564			$	431		$	2,456
	December 31, 2013
	(In millions)		Level 1				Level 2				Level 3			Total Assets
														at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds		$	—			$	505			$	15		$	520
	States, municipalities and political subdivisions		—				73				—			73
	Asset-backed:
	Residential mortgage-backed		—				130				—			130
	Commercial mortgage-backed		—				106				—			106
	Other asset-backed		—				12				—			12
	Total asset-backed		—				248				—			248
	Total fixed maturity securities		—				826				15			841
	Equity securities		480				117				8			605
	Derivative financial instruments		2				—				—			2
	Short term investments		45				49				—			94
	Limited partnerships:
	Hedge funds		—				647				322			969
	Private equity		—				—				114			114
	Total limited partnerships		—				647				436			1,083
	Other assets		—				31				—			31
	Total assets		$	527			$	1,670			$	459		$	2,656
Reconciliation of level 3 plan assets	The tables below present a reconciliation for all pension plan assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the years ended December 31, 2014 and 2013.
	Level 3	Balance at January 1, 2014				Actual return on assets still held at December 31, 2014				Actual return on assets sold during the year ended December 31, 2014			Purchases, sales and settlements			Net transfers into (out of) Level 3			Balance at December 31, 2014
	(In millions)
	Fixed maturity securities:
	Corporate and other bonds	$	15			$	—			$	—		$	—		$	—		$	15
	Equity securities	8				—				—			(8		)	—			—
	Limited partnerships:
	Hedge funds	322				19				—			(38		)	—			303
	Private equity	114				19				—			(20		)	—			113
	Total limited partnerships	436				38				—			(58		)	—			416
	Total	$	459			$	38			$	—		$	(66	)	$	—		$	431
	Level 3	Balance at January 1, 2013				Actual return on assets still held at December 31, 2013				Actual return on assets sold during the year ended December 31, 2013			Purchases, sales and settlements			Net transfers into (out of) Level 3			Balance at December 31, 2013
	(In millions)
	Fixed maturity securities:
	Corporate and other bonds	$	11			$	(1	)		$	—		$	5		$	—		$	15
	Equity securities	5				3				—			—			—			8
	Limited partnerships:
	Hedge funds	359				56				—			(77		)	(16		)	322
	Private equity	62				—				—			52			—			114
	Total limited partnerships	421				56				—			(25		)	(16		)	436
	Investment contracts with insurance company	10				—				—			(10		)	—			—
	Total	$	447			$	58			$	—		$	(30	)	$	(16	)	$	459
Estimated future minimum benefit payments to participants	Estimated Future Minimum Benefit Payments to Participants
	(In millions)	Pension Benefits				Postretirement Benefits
	2015	$	179			$	5
	2016	181				4
	2017	180				4
	2018	184				4
	2019	185				3
	2020-2024	936				9

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Restricted shares, performance-based restricted share units and performance share unit activity	The following table presents activity for non-vested restricted shares, performance-based RSUs and performance share units under the Plan in 2014.
		Number of Awards		Weighted-Average Grant Date Fair Value
	Balance at January 1, 2014	847,674		$	29.61
	Awards granted	261,273		41.01
	Awards vested	(156,332	)	28.42
	Awards forfeited, canceled or expired	(91,002	)	32.09
	Performance-based adjustment	52,568		28.5
	Balance at December 31, 2014	914,181		$	32.76

Other_Intangible_Assets_Tables

Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Intangible Assets, Gross (Excluding Goodwill) [Abstract]
Schedule of Other Intangible Assets	Other intangible assets are presented in the following table.
	31-Dec		2014				2013
	(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	$	60	$	61	$	64	$	63
	Trade name	8 years	8		3		8		2
	Distribution channel	15 years	12		2		13		1
	Total finite-lived intangible assets		80		66		85		66
	Indefinite-lived intangible assets:
	Syndicate capacity		55				58
	Agency force		16				16
	Total indefinite-lived intangible assets		71				74
	Total other intangible assets		$	151	$	66	$	159	$	66

Operating_Leases_Commitments_a1

Operating Leases, Commitments and Contingencies, and Guarantees (Tables)	12 Months Ended
	Dec. 31, 2014
Operating Leases, Commitments and Contingencies, and Guarantees [Abstract]
Future minimum lease payments and sublease receipts	Future Minimum Lease Payments and Sublease Receipts
	(In millions)	Future Minimum Lease Payments		Future Minimum Sublease Receipts
	2015	$	36	$	—
	2016	35		—
	2017	30		—
	2018	25		—
	2019	21		1
	Thereafter	98		1
	Total	$	245	$	2

Stockholders_Equity_and_Statut1

Stockholders' Equity and Statutory Accounting Practices (Tables)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity and Statutory Accounting Practices [Abstract]
Combined statutory capital and surplus and net income (loss)	Statutory Information
		Statutory Capital and Surplus				Statutory Net Income (Loss)
		31-Dec				Years ended December 31
	(In millions)	2014 (a)		2013 (b)		2014 (a)		2013		2012
	Combined Continental Casualty Companies	$	11,155	$	11,137	$	914	$	913	$	391
	Life company			597		37		48		44
	________________
	(a)	Information derived from the statutory-basis financial statements to be filed with insurance regulators.
	(b)	Represents the combined statutory surplus of CCC and its subsidiaries, including the life company.

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) by Component (Tables)	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss) by Component	The table below displays the changes in Accumulated other comprehensive income (loss) by component for the years ended December 31, 2014 and 2013.
		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 December 31, 2013	$	26		$	692		$	—		$	(426	)	$	150		$	442
	Change due to sale of subsidiaries	(5		)	(17		)	22			—			—			—
	Other comprehensive income (loss) before reclassifications	15			295			12			(219		)	(95		)	8
	Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(10), $(23), $7, $0 and $(26)	—			28			34			(12		)	—			50
	Other comprehensive income (loss) after tax (expense) benefit of $(8), $(122), $15, $111, $0 and $(4)	15			267			(22		)	(207		)	(95		)	(42		)
	Balance at December 31, 2014	$	36		$	942		$	—		$	(633	)	$	55		$	400
		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 December 31, 2012	$	20		$	1,371		$	(721	)	$	161		$	831
	Other comprehensive income (loss) before reclassifications	6			(658		)	275			(11		)	(388		)
	Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit of $0, $(10), $11, $0 and $1	—			21			(20		)	—			1
	Other comprehensive income (loss) after tax (expense) benefit of $(3), $364, $(158), $0 and $203	6			(679		)	295			(11		)	(389		)
	Balance at December 31, 2013	$	26		$	692		$	(426	)	$	150		$	442

Business_Segments_Tables

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Significant components of the Company's continuing operations and selected balance sheet items
	Year ended December 31, 2014	Specialty			Commercial			International			Life &			Corporate
											Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Net written premiums	$	2,839		$	2,817		$	880		$	553		$	1		$	(2	)	$	7,088
	Operating revenues
	Net earned premiums	$	2,838		$	2,906		$	913		$	556		$	1		$	(2	)	$	7,212
	Net investment income	560			723			61			700			23			—			2,067
	Other revenues	295			38			—			16			12			(5		)	356
	Total operating revenues	3,693			3,667			974			1,272			36			(7		)	9,635
	Claims, Benefits and Expenses
	Net incurred claims and benefits	1,627			2,187			488			1,304			(29		)	—			5,577
	Policyholders’ dividends	6			8			—			—			—			—			14
	Amortization of deferred acquisition costs	592			493			204			28			—			—			1,317
	Other insurance related expenses	262			487			151			130			1			(2		)	1,029
	Other expenses	254			31			28			30			210			(5		)	548
	Total claims, benefits and expenses	2,741			3,206			871			1,492			182			(7		)	8,485
	Operating income (loss) from continuing operations before income tax	952			461			103			(220		)	(146		)	—			1,150
	Income tax (expense) benefit on operating income (loss)	(318		)	(154		)	(34		)	151			54			—			(301		)
	Net operating income (loss) from continuing operations	634			307			69			(69		)	(92		)	—			849
	Net realized investment gains (losses), pretax	15			16			(1		)	7			20			—			57
	Income tax (expense) benefit on net realized investment gains (losses)	(5		)	(6		)	1			—			(8		)	—			(18		)
	Net realized investment gains (losses)	10			10			—			7			12			—			39
	Net income (loss) from continuing operations	$	644		$	317		$	69		$	(62	)	$	(80	)	$	—		$	888
	December 31, 2014
	(In millions)
	Reinsurance receivables	$	567		$	690		$	207		$	525		$	2,753		$	—		$	4,742
	Insurance receivables	778			954			250			13			2			—			1,997
	Deferred acquisition costs	304			213			83			—			—			—			600
	Goodwill	117			—			35			—			—			—			152
	Insurance reserves
	Claim and claim adjustment expenses	6,229			9,514			1,441			3,183			2,904			—			23,271
	Unearned premiums	1,763			1,273			431			125			—			—			3,592
	Future policy benefits	—			—			—			9,490			—			—			9,490
	Policyholders’ funds	9			18			—			—			—			—			27
	Year ended December 31, 2013	Specialty			Commercial			International			Life &			Corporate
											Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Net written premiums	$	2,880		$	2,960		$	959		$	552		$	(1	)	$	(2	)	$	7,348
	Operating revenues
	Net earned premiums	$	2,795		$	3,004		$	916		$	559		$	(1	)	$	(2	)	$	7,271
	Net investment income	629			899			60			662			32			—			2,282
	Other revenues	257			96			—			(4		)	12			(2		)	359
	Total operating revenues	3,681			3,999			976			1,217			43			(4		)	9,912
	Claims, Benefits and Expenses
	Net incurred claims and benefits	1,593			2,259			489			1,261			191			—			5,793
	Policyholders’ dividends	6			7			—			—			—			—			13
	Amortization of deferred acquisition costs	585			526			223			28			—			—			1,362
	Other insurance related expenses	250			498			140			130			(3		)	(2		)	1,013
	Other expenses	237			32			12			13			183			(2		)	475
	Total claims, benefits and expenses	2,671			3,322			864			1,432			371			(4		)	8,656
	Operating income (loss) from continuing operations before income tax	1,010			677			112			(215		)	(328		)	—			1,256
	Income tax (expense) benefit on operating income (loss)	(342		)	(229		)	(43		)	141			118			—			(355		)
	Net operating income (loss) from continuing operations	668			448			69			(74		)	(210		)	—			901
	Net realized investment gains (losses), pretax	(5		)	(15		)	5			26			9			—			20
	Income tax (expense) benefit on net realized investment gains (losses)	2			5			(2		)	(8		)	(3		)	—			(6		)
	Net realized investment gains (losses)	(3		)	(10		)	3			18			6			—			14
	Net income (loss) from continuing operations	$	665		$	438		$	72		$	(56	)	$	(204	)	$	—		$	915
	December 31, 2013
	(In millions)
	Reinsurance receivables	$	500		$	1,024		$	294		$	1,203		$	3,067		$	—		$	6,088
	Insurance receivables	732			1,019			299			11			2			—			2,063
	Deferred acquisition costs	299			226			99			—			—			—			624
	Goodwill	117			—			38			—			—			—			155
Insurance reserves
Claim and claim adjustment expenses	6,058			10,091			1,575			3,058			3,307			—			24,089
Unearned premiums	1,710			1,374			506			128			—			—			3,718
Future policy benefits	—			—			—			10,471			—			—			10,471
Policyholders’ funds	9			15			—			92			—			—			116
Year ended December 31, 2012	Specialty			Commercial						Life &			Corporate
										Group			& Other
(In millions)							International(a)			Non-Core			Non-Core			Eliminations			Total
Net written premiums	$	2,733		$	3,033		$	648		$	553		$	(1	)	$	(2	)	$	6,964
Operating revenues
Net earned premiums	$	2,709		$	2,968		$	647		$	559		$	—		$	(2	)	$	6,881
Net investment income	564			826			59			629			32			—			2,110
Other revenues	231			41			(1		)	33			16			(1		)	319
Total operating revenues	3,504			3,835			705			1,221			48			(3		)	9,310
Claims, Benefits and Expenses
Net incurred claims and benefits	1,746			2,370			361			1,255			(16		)	—			5,716
Policyholders’ dividends	2			11			—			—			—			—			13
Amortization of deferred acquisition costs	574			520			152			28			—			—			1,274
Other insurance related expenses	278			532			94			142			3			(2		)	1,047
Other expenses	207			37			7			22			183			(1		)	455
Total claims, benefits and expenses	2,807			3,470			614			1,447			170			(3		)	8,505
Operating income (loss) from continuing operations before income tax	697			365			91			(226		)	(122		)	—			805
Income tax (expense) benefit on operating income (loss)	(235		)	(120		)	(40		)	134			41			—			(220		)
Net operating income (loss) from continuing operations	462			245			51			(92		)	(81		)	—			585
Net realized investment gains (losses), pretax	18			34			7			(9		)	4			—			54
Income tax (expense) benefit on net realized investment gains (losses)	(8		)	(11		)	(1		)	3			(2		)	—			(19		)
Net realized investment gains (losses)	10			23			6			(6		)	2			—			35
Net income (loss) from continuing operations	$	472		$	268		$	57		$	(98	)	$	(79	)	$	—		$	620
____________________
Revenues by line of business	Revenues by Line of Business
	Years ended December 31
	(In millions)	2014			2013			2012
	Specialty
	Management & Professional Liability	$	2,818		$	2,836		$	2,723
	Surety	509			490			485
	Warranty & Alternative Risks	381			350			314
	Specialty revenues	3,708			3,676			3,522
	Commercial
	Middle Market	1,631			1,642			1,560
	Small Business	709			754			669
	Other Commercial Insurance	1,343			1,588			1,640
	Commercial revenues	3,683			3,984			3,869
	International
	Canada	273			289			276
	CNA Europe	335			326			313
	Hardy	365			366			123
	International revenues	973			981			712
	Life & Group Non-Core revenues	1,279			1,243			1,212
	Corporate & Other Non-Core revenues	56			52			52
	Eliminations	(7		)	(4		)	(3		)
	Total revenues	$	9,692		$	9,932		$	9,364

Discontinued_Operations_Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Results of discontinued operations	The results of discontinued operations reflected in the Consolidated Statements of Operations were as follows:
	Years ended December 31
	(In millions)	2014			2013			2012
	Revenues
	Net earned premiums	$	—		$	—		$	1
	Net investment income	94			168			172
	Net realized investment gains	3			11			9
	Other revenues	—			2			1
	Total revenues	97			181			183
	Claims, Benefits and Expenses
	Insurance claims and policyholders' benefits	75			141			167
	Other operating expenses	2			3			3
	Total claims, benefits and expenses	77			144			170
	Income before income tax	20			37			13
	Income tax expense	(6		)	(15		)	(5		)
	Income from operations of discontinued operations, net of income tax	14			22			8
	Loss on sale, net of income tax benefit of $40, $0 and $0	(211		)	—			—
	(Loss) income from discontinued operations	$	(197	)	$	22		$	8

Quarterly_Financial_Data_Unaud1

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Data [Abstract]
Schedule of quarterly financial information	Quarterly Financial Data
	2014
	(In millions, except per share data)	First		Second		Third		Fourth		Full Year
	Revenues	$	2,463	$	2,440	$	2,411	$	2,378	$	9,692
	Net income (loss) (a)	$	13	$	267	$	213	$	198	$	691
	Basic earnings (loss) per share	$	0.05	$	0.99	$	0.79	$	0.73	$	2.56
	Diluted earnings (loss) per share	$	0.05	$	0.98	$	0.79	$	0.73	$	2.55
	2013
	(In millions, except per share data)	First		Second		Third		Fourth		Full Year
	Revenues	$	2,455	$	2,450	$	2,458	$	2,569	$	9,932
	Net income (loss)	$	250	$	194	$	272	$	221	$	937
	Basic earnings (loss) per share	$	0.93	$	0.72	$	1.01	$	0.82	$	3.48
	Diluted earnings (loss) per share (b)	$	0.93	$	0.72	$	1.01	$	0.82	$	3.47
	____________________
	(a)	Net income in the first quarter of 2014 includes the impairment loss on the sale of CAC.
	(b)	Due to the averaging of shares, quarterly earnings per share do not add to the total for the full year.

Schedule_V_Valuation_and_Quali1

Schedule V. Valuation and Qualifying Accounts (Tables)	12 Months Ended
	Dec. 31, 2014
Valuation and Qualifying Accounts [Abstract]
Schedule of valuation and qualifying accounts	SCHEDULE V. VALUATION AND QUALIFYING ACCOUNTS
	(In millions)	Balance at Beginning of Period		Charged to Costs and Expenses			Charged to Other Accounts (a)			Deductions			Balance at End of Period
	Year ended December 31, 2014
	Deducted from assets:
	Allowance for doubtful accounts:
	Insurance and reinsurance receivables	$	155	$	(40	)	$	(1	)	$	(5	)	$	109
	Year ended December 31, 2013
	Deducted from assets:
	Allowance for doubtful accounts:
	Insurance and reinsurance receivables	$	174	$	(6	)	$	(3	)	$	(10	)	$	155
	Year ended December 31, 2012
	Deducted from assets:
	Allowance for doubtful accounts:
	Insurance and reinsurance receivables	$	203	$	(23	)	$	5		$	(11	)	$	174
	(a)    Amount includes effects of foreign currency translation.

Schedule_VI_Supplemental_Infor1

Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations (Tables)	12 Months Ended
	Dec. 31, 2014
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]
Supplemental information concerning property and casualty insurance operations	SCHEDULE VI. SUPPLEMENTAL INFORMATION CONCERNING PROPERTY AND CASUALTY INSURANCE OPERATIONS
	As of and for the years ended December 31	Consolidated Property and Casualty Operations
	(In millions)	2014			2013			2012
	Deferred acquisition costs	$	600		$	624
	Reserves for unpaid claim and claim adjustment expenses	23,271			24,015
	Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.5% to 8.0%)	1,578			1,586
	Unearned premiums	3,592			3,718
	Net written premiums	7,088			7,348			$	6,964
	Net earned premiums	7,212			7,271			6,881
	Net investment income	2,031			2,240			2,074
	Incurred claim and claim adjustment expenses related to current year	5,043			5,113			5,266
	Incurred claim and claim adjustment expenses related to prior years	(39		)	(115		)	(180		)
	Amortization of deferred acquisition costs	1,317			1,362			1,274
	Paid claim and claim adjustment expenses	5,297			5,566			5,257

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
Share data in Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loss on reinsurance transaction	$34,000,000
Business Acquisition, Purchase Price			231,000,000
Business Combination, Acquisition Related Costs			4,000,000
Anticipated amounts due from insureds related to losses under deductible policies	1,400,000,000	1,300,000,000
Minimum interest rate used in determining present value of obligations of structured settlements not funded by annuities	5.50%	7.10%
Maximum interest rate used in determining present value of obligations of structured settlements not funded by annuities	8.00%	9.70%
Discounted reserves for unfunded structured settlements	582,000,000	580,000,000
Discounted reserves for unfunded structure settlements, discount amount	924,000,000	969,000,000
Minimum interest rate used to discount workers' compensation lifetime claim reserves and accident and health claim reserves	3.50%	3.00%
Maximum interest rate used to discount workers' compensation lifetime claim reserves and accident and health claim reserves	6.80%	6.80%
Discounted reserves for worker's compensation lifetime claim reserves and accident and health claim reserves	2,500,000,000	2,400,000,000
Discounted reserves for worker's compensation lifetime claim reserves and accident and health claim reserves, discount amount	654,000,000	617,000,000
Minimum interest rate used to calculate reserves for long term care products	4.50%	4.50%
Maximum interest rate used to calculate reserves for payout annuity contracts	7.90%	7.90%
Minimum interest rate used to calculate reserves for payout annuity contracts		5.00%
Maximum interest rate used to calculate reserves for payout annuity contracts		8.70%
Liability balance for guaranty fund	131,000,000	143,000,000
Percentage of billed receivables compared to total reinsurance receivables	5% or less
Deposit assets	3,000,000	3,000,000
Deposit liabilities	9,000,000	130,000,000
Deferred acquisition costs, net of shadow adjustment	314,000,000	342,000,000
Investments in life settlement contracts	82,000,000	88,000,000
Increase (decrease) in fair value recognized on life settlement contracts	8,000,000	-2,000,000	11,000,000
Gain recognized on matured life settlement contracts	25,000,000	15,000,000	42,000,000
Decrease in shadow adjustment, net of tax		979,000,000
Increase in shadow adjustment, net of tax	756,000,000
Reduction of net unrealized gains on investments included in AOCI due to shadow adjustments	1,288,000,000	532,000,000
Foreign currency transaction gain (loss), before tax	-25,000,000	2,000,000	12,000,000
Weighted average number diluted shares outstanding adjustment	675	552	417
Antidilutive securities excluded from computation of earnings per share, amount	170	111	730
Interest paid, net	179,000,000	164,000,000	170,000,000
Proceeds from income tax refunds			29,000,000
Income taxes paid	$313,000,000	$129,000,000
Furniture and Fixtures [Member]
Property, Plant and Equipment, Useful Life	7 years
Office Equipment [Member]
Property, Plant and Equipment, Useful Life	5 years
Building and Building Improvements [Member]
Property, Plant and Equipment, Useful Life	50 years
Minimum [Member]
Requisite service period for stock- based compensation expense	3 years
Minimum [Member] | Software [Member]
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member]
Requisite service period for stock- based compensation expense	4 years
Maximum [Member] | Software [Member]
Property, Plant and Equipment, Useful Life	5 years
Property and Casualty insurance core operations [Member]
Number of Operating Segments	3
Life and Group Non-Core & Corporate and Other Non-Core operations [Member]
Number of Operating Segments	2

Summary_of_Significant_Account4

Summary of Significant Accounting Policies (Life Settlement Contracts) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Life Settlement Contracts, Fair Value Method, Number of Contracts, Fiscal Year Maturity [Abstract]
Life settlement contracts, fair value method, number of contracts, maturing in next twelve months	60
Life settlement contracts, fair value method, number of contracts, maturing in year two	60
Life settlement contracts, fair value method, number of contracts, maturing in year three	50
Life settlement contracts, fair value method, number of contracts, maturing in year four	50
Life settlement contracts, fair value method, number of contracts, maturing in year five	50
Life settlement contracts, fair value method, number of contracts, maturing after year five	318
Life settlement contracts, fair value method, number of contracts	588
Life settlement contracts, fair value, maturing in next twelve months	$11
Life settlement contracts, fair value, maturing in year two	10
Life settlement contracts, fair value, maturing in year three	9
Life settlement contracts, fair value, maturing in year four	7
Life settlement contracts, fair value, maturing in year five	6
Life settlement contracts, fair value, maturing after year five	39
Life settlement contracts, fair value	82	88
Life settlement contracts, fair value method, face value, maturing in next twelve months	37
Life settlement contracts, fair value method, face value, maturing in year two	33
Life settlement contracts, fair value method, face value, maturing in year three	30
Life settlement contracts, fair value method, face value, maturing in year four	26
Life settlement contracts, fair value method, face value, maturing in year five	26
Life settlement contracts, fair value method, face value, maturing after year five	187
Life settlement contracts, fair value method, face value	$339

Investments_Narrative_Details

Investments (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments [Abstract]
Number of non-income producing fixed maturity securities	0	0
Number of investments that exceed ten percent of stockholders' equity	0	0
Limited partnership investments	$2,937,000,000	$2,720,000,000
Undistributed earnings of limited partnership investments	1,040,000,000	969,000,000
Percentage of limited partnerships reported on a current basis	65.00%
Percentage of limited partnerships reported on a one month lag	16.00%
Number of active limited partnership investments held	86	87
Percentage of limited partnerships employing hedge fund strategies focused on fixed income and equity investments	73.00%	74.00%
Limited partnerships invested in private debt and equity	23.00%	22.00%
Percentage of equity related limited partnership hedge fund strategies	56.00%
Percentage of multistrategy approach limited partnership hedge fund strategies	27.00%
Percentage of distressed investments limited partnership hedge fund strategies	14.00%
Percentage of fixed income limited partnership hedge fund strategies	3.00%
Carrying value of ten largest limited partnerships	1,492,000,000	1,471,000,000
Carrying value of limited partnerships as percentage of aggregate partnership equity	4.00%	4.00%
Income As Percentage Of Change In Partnership Equity For All Limited Partnerships	4.00%	4.00%	3.00%
Commercial mortgage loans past due or in non-accrual status	0	0
Valuation allowances recorded on commercial mortgage loans	0	0
Future capital call commitments for limited partnership investments	327,000,000
Mortgage loan commitments	8,000,000
Commitments to purchase or fund privately placed debt securities	75,000,000
Commitments to sell various privately placed debt securities	97,000,000
Carrying value of securities deposited under requirements of regulatory authorities	3,000,000,000	3,300,000,000
Cash and securities deposited as collateral for letters of credit	361,000,000	353,000,000
Carrying value of assets deposited to secure reinsurance and third party obligations	$302,000,000	$294,000,000

Investments_Net_investment_inc

Investments (Net investment income) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Investment Income [Line Items]
Gross investment income	$2,125	$2,335	$2,162
Investment expense	-58	-53	-52
Net investment income	2,067	2,282	2,110
Fixed maturity securities [Member]
Net Investment Income [Line Items]
Gross investment income	1,803	1,827	1,846
Short term investments [Member]
Net Investment Income [Line Items]
Gross investment income	3	3	5
Limited partnership investments [Member]
Net Investment Income [Line Items]
Gross investment income	263	451	251
Equity securities [Member]
Net Investment Income [Line Items]
Gross investment income	12	12	12
Mortgage loans [Member]
Net Investment Income [Line Items]
Gross investment income	31	23	17
Trading portfolio [Member]
Net Investment Income [Line Items]
Gross investment income	10	17	24
Other [Member]
Net Investment Income [Line Items]
Gross investment income	$3	$2	$7

Investments_Net_realized_inves

Investments (Net realized investment gains (losses)) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net realized investment gains (losses)	$57	$20	$54
Fixed maturity securities [Member]
Gross realized gains	170	185	222
Gross realized losses	-129	-144	-145
Net realized investment gains (losses)	41	41	77
Equity securities [Member]
Gross realized gains	8	13	19
Gross realized losses	-7	-35	-42
Net realized investment gains (losses)	1	-22	-23
Derivative [Member]
Net realized investment gains (losses)	-1	-9	-2
Short term Invest and other [Member]
Net realized investment gains (losses)	$16	$10	$2

Investments_Net_change_in_unre

Investments (Net change in unrealized gains (losses) on investments) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net change in unrealized gains (losses) on investments	$1,517	($2,556)	$1,875
Fixed maturity securities [Member]
Net change in unrealized gains (losses) on investments	1,511	-2,541	1,871
Equity securities [Member]
Net change in unrealized gains (losses) on investments	6	-15	5
Other [Member]
Net change in unrealized gains (losses) on investments			($1)

Investments_Components_of_othe

Investments (Components of other-than-temporary impairment losses recognized in earnings) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other-than-temporary impairment losses recognized in earnings	$77	$76	$150
Corporate and other bonds [Member]
Other-than-temporary impairment losses recognized in earnings	18	20	25
States, municipalities and political subdivisions [Member]
Other-than-temporary impairment losses recognized in earnings	46		34
Residential mortgage-backed [Member]
Other-than-temporary impairment losses recognized in earnings	5	19	48
Other asset-backed [Member]
Other-than-temporary impairment losses recognized in earnings	1	2
Total asset-backed [Member]
Other-than-temporary impairment losses recognized in earnings	6	21	48
U.S. Treasury and obligations of government-sponsored enterprises [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	70	41	108
Common stock [Member]
Other-than-temporary impairment losses recognized in earnings	7	8	6
Preferred stock [Member]
Other-than-temporary impairment losses recognized in earnings		26	36
Total equity securities available-for-sale [Member]
Other-than-temporary impairment losses recognized in earnings	7	34	42
Short term investments [Member]
Other-than-temporary impairment losses recognized in earnings		$1

Investments_Summary_of_fixed_m

Investments (Summary of fixed maturity and equity securities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Cost or Amortized Cost	$37,545	$39,490
Gross Unrealized Gain	3,544	2,460
Gross Unrealized Loss	99	532
Estimated fair value	40,990	41,418
Corporate and other bonds [Member]
Cost or Amortized Cost	17,210	19,352
Gross Unrealized Gain	1,721	1,645
Gross Unrealized Loss	61	135
Estimated fair value	18,870	20,862
Unrealized OTTI Losses (Gains)	0	0
States, municipalities and political subdivisions [Member]
Cost or Amortized Cost	11,285	11,281
Gross Unrealized Gain	1,463	548
Gross Unrealized Loss	8	272
Estimated fair value	12,740	11,557
Unrealized OTTI Losses (Gains)	0	0
Residential mortgage-backed [Member]
Cost or Amortized Cost	5,028	4,940
Gross Unrealized Gain	218	123
Gross Unrealized Loss	13	92
Estimated fair value	5,233	4,971
Unrealized OTTI Losses (Gains)	-53	-37
Commercial mortgage-backed [Member]
Cost or Amortized Cost	2,056	1,995
Gross Unrealized Gain	93	90
Gross Unrealized Loss	5	22
Estimated fair value	2,144	2,063
Unrealized OTTI Losses (Gains)	-2	-3
Other asset-backed [Member]
Cost or Amortized Cost	1,234	945
Gross Unrealized Gain	11	13
Gross Unrealized Loss	10	3
Estimated fair value	1,235	955
Unrealized OTTI Losses (Gains)	0	0
Total asset-backed [Member]
Cost or Amortized Cost	8,318	7,880
Gross Unrealized Gain	322	226
Gross Unrealized Loss	28	117
Estimated fair value	8,612	7,989
Unrealized OTTI Losses (Gains)	-55	-40
U.S. Treasury and obligations of government-sponsored enterprises [Member]
Cost or Amortized Cost	26	139
Gross Unrealized Gain	5	6
Gross Unrealized Loss	0	1
Estimated fair value	31	144
Unrealized OTTI Losses (Gains)	0	0
Foreign Government Debt Securities [Member]
Cost or Amortized Cost	438	531
Gross Unrealized Gain	16	15
Gross Unrealized Loss	0	3
Estimated fair value	454	543
Unrealized OTTI Losses (Gains)	0	0
Redeemable preferred stock [Member]
Cost or Amortized Cost	39	92
Gross Unrealized Gain	3	10
Gross Unrealized Loss	0	0
Estimated fair value	42	102
Unrealized OTTI Losses (Gains)	0	0
Total fixed maturity securities available-for-sale [Member]
Cost or Amortized Cost	37,316	39,275
Gross Unrealized Gain	3,530	2,450
Gross Unrealized Loss	97	528
Estimated fair value	40,749	41,197
Unrealized OTTI Losses (Gains)	-55	-40
Total fixed maturity securities trading [Member]
Cost or Amortized Cost, Trading Securities	19	36
Estimated Fair Value, Trading Securities	19	36
Common stock [Member]
Cost or Amortized Cost	38	36
Gross Unrealized Gain	9	9
Gross Unrealized Loss	0	0
Estimated fair value	47	45
Preferred stock [Member]
Cost or Amortized Cost	172	143
Gross Unrealized Gain	5	1
Gross Unrealized Loss	2	4
Estimated fair value	175	140
Total equity securities available-for-sale [Member]
Cost or Amortized Cost	210	179
Gross Unrealized Gain	14	10
Gross Unrealized Loss	2	4
Estimated fair value	$222	$185

Investments_Securities_in_a_gr

Investments (Securities in a gross unrealized loss position) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	$2,855	$9,256
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	70	388
Estimated Fair Value, 12 Months or Longer	707	544
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	29	144
Estimated Fair Value, Total	3,562	9,800
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	99	532
Corporate and other bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	1,330	3,592
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	46	129
Estimated Fair Value, 12 Months or Longer	277	72
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	15	6
Estimated Fair Value, Total	1,607	3,664
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	61	135
States, municipalities and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	335	3,251
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	5	197
Estimated Fair Value, 12 Months or Longer	127	129
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	3	75
Estimated Fair Value, Total	462	3,380
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	8	272
Residential mortgage-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	293	1,293
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	5	29
Estimated Fair Value, 12 Months or Longer	189	343
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	8	63
Estimated Fair Value, Total	482	1,636
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	13	92
Commercial mortgage-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	264	640
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2	22
Estimated Fair Value, 12 Months or Longer	99	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	3	0
Estimated Fair Value, Total	363	640
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	5	22
Other asset-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	607	269
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	10	3
Estimated Fair Value, 12 Months or Longer	7	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Estimated Fair Value, Total	614	269
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	10	3
Total asset-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	1,164	2,202
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	17	54
Estimated Fair Value, 12 Months or Longer	295	343
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	11	63
Estimated Fair Value, Total	1,459	2,545
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	28	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	3	13
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	1
Estimated Fair Value, 12 Months or Longer	4	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Estimated Fair Value, Total	7	13
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	1
Foreign Government Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	3	111
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	3
Estimated Fair Value, 12 Months or Longer	3	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Estimated Fair Value, Total	6	111
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	3
Redeemable preferred stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0
Estimated Fair Value, 12 Months or Longer	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Estimated Fair Value, Total	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0
Total fixed maturity securities available-for-sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	2,838	9,169
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	68	384
Estimated Fair Value, 12 Months or Longer	706	544
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	29	144
Estimated Fair Value, Total	3,544	9,713
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	97	528
Preferred stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	17	87
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2	4
Estimated Fair Value, 12 Months or Longer	1	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Estimated Fair Value, Total	18	87
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$2	$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 $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance of credit losses on fixed maturity securities	$74	$95	$92
Additional credit losses for securities for which an OTTI loss was previously recognized		2	23
Credit losses for securities for which an OTTI loss was previously recognized			2
Reductions for securities sold during the period	-9	-23	-14
Reductions for securities the Company intends to sell or more likely than not will be required to sell	-3		-8
Ending balance of credit losses on fixed maturity securities	$62	$74	$95

Investments_Contractual_maturi

Investments (Contractual maturity) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Investments [Abstract]
Due in one year or less, cost or amortized cost	$2,479	$2,420
Due after one year through five years, cost or amortized cost	9,054	9,496
Due after five years through ten years, cost or amortized cost	12,055	11,667
Due after ten years, cost or amortized cost	13,728	15,692
Total Amortized Cost Basis	37,316	39,275
Due in one year or less, estimated fair value	2,511	2,455
Due after one year through five years, estimated fair value	9,605	10,068
Due after five years through ten years, estimated fair value	12,584	11,954
Due after ten years, estimated fair value	16,049	16,720
Total Estimated Fair Value	$40,749	$41,197

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Summary of Derivative Instruments [Abstract]
Fair value of cash collateral by the Company	$0	$0
Fair value of cash collateral received from counterparties	$0	$0

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Summary of aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivative [Line Items]
Estimated fair value asset	$0
Estimated fair value (liability)	-3
Not Designated as Hedging Instrument [Member] | Currency forwards [Member]
Derivative [Line Items]
Derivative, Notional Amount	9
Estimated fair value asset	0
Estimated fair value (liability)	0
Not Designated as Hedging Instrument [Member] | Equity warrants [Member]
Derivative [Line Items]
Derivative, Notional Amount	5	5
Estimated fair value asset	0	0
Estimated fair value (liability)	0	0
Not Designated as Hedging Instrument [Member] | Embedded Derivative Financial Instruments [Member]
Derivative [Line Items]
Derivative, Notional Amount	184
Estimated fair value asset	0
Estimated fair value (liability)	($3)

Fair_Value_Assets_and_liabilit

Fair Value (Assets and liabilities measured at fair value on a recurring basis) (Details) (USD $)	Dec. 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	$42,757	$43,073
Fair value of liabilities, measured on a recurring basis	-3
Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	18,889	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	12,740	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	5,233	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	2,144	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	1,235	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	8,612	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	31	144
Foreign Government Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	454	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	42	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	40,768	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	222	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	41	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	1,644	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	82	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
Embedded Derivative Financial Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities, measured on a recurring basis	-3
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	957	1,179
Fair value of liabilities, measured on a recurring basis	0
Level 1 [Member] | Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	32	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	0	0
Level 1 [Member] | Residential mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 1 [Member] | Commercial mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 1 [Member] | Other asset-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 1 [Member] | 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	28	116
Level 1 [Member] | Foreign Government Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	41	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	30	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	131	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	145	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	0	0
Level 1 [Member] | Short term investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	681	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	0	0
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] | Embedded Derivative Financial Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities, measured on a recurring basis	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	40,519	40,591
Fair value of liabilities, measured on a recurring basis	-3
Level 2 [Member] | Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	18,695	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	12,646	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	5,044	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	2,061	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	580	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	7,685	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	3	28
Level 2 [Member] | Foreign Government Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	413	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	12	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	39,454	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	61	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	41	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	963	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	0	0
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] | Embedded Derivative Financial Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities, measured on a recurring basis	-3
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,281	1,303
Fair value of liabilities, measured on a recurring basis	0
Level 3 [Member] | Corporate and other bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	162	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	94	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	189	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	83	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	655	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	927	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	0	0
Level 3 [Member] | Foreign Government Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 3 [Member] | Redeemable preferred stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 3 [Member] | Fixed maturity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,183	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	16	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	0	0
Level 3 [Member] | Short term investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	0	0
Level 3 [Member] | Life settlement contracts, included in Other assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	82	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] | Embedded Derivative Financial Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities, measured on a recurring basis	$0

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 $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 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)	27	-5
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	46
Purchases	673	804
Sales	-386	-414
Settlements	-273	-275
Transfers into Level 3	107	94
Transfers out of Level 3	-216	-294
Balance, Ending, Assets	1,281	1,303
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	7	-36
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)	-9	9
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	52	-3
Purchases	657	801
Sales	-378	-405
Settlements	-234	-251
Transfers into Level 3	107	94
Transfers out of Level 3	-215	-293
Balance, Ending, Assets	1,183	1,203
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-1	-7
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)	2	3
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-1
Purchases	33	142
Sales	-23	-116
Settlements	-16	-44
Transfers into Level 3	18	51
Transfers out of Level 3	-55	-51
Balance, Ending, Assets	162	204
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)		-2
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)	1	-2
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	4	4
Purchases	14	122
Sales	-10	-79
Settlements		-61
Transfers into Level 3	14	18
Transfers out of Level 3		-27
Balance, Ending, Assets	94	71
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)	-21	4
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	61	-14
Purchases	94	116
Sales	-174	-10
Settlements	-72	-75
Transfers into Level 3	32	4
Transfers out of Level 3	-62	-107
Balance, Ending, Assets	189	331
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)		-3
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)	7
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-6	11
Purchases	28	107
Sales	-60	-3
Settlements	-29	-11
Transfers into Level 3	43	21
Transfers out of Level 3	-51	-103
Balance, Ending, Assets	83	151
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)	2	5
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-6	-4
Purchases	488	314
Sales	-111	-197
Settlements	-117	-35
Transfers out of Level 3	-47	-5
Balance, Ending, Assets	655	446
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-1	-2
Total asset-backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	928	910
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	-12	9
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	49	-7
Purchases	610	537
Sales	-345	-210
Settlements	-218	-121
Transfers into Level 3	75	25
Transfers out of Level 3	-160	-215
Balance, Ending, Assets	927	928
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-1	-5
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)		-1
Settlements		-25
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	-27
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-6	3
Purchases	16	2
Sales	-8
Transfers out of Level 3		-1
Balance, Ending, Assets	16	11
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)		-27
Other invested assets, including derivatives, net
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Sales		-1
Settlements		1
Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets		6
Sales		-6
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)	33	13
Settlements	-39	-25
Balance, Ending, Assets	82	88
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	8	-2
Separate account business [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning, Assets	1	2
Purchases		1
Sales		-2
Transfers out of Level 3	-1
Balance, Ending, Assets		$1

Fair_Value_Narrative_Details

Fair Value (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	$24	$0
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$1	$0

Fair_Value_Quantitative_inform

Fair Value (Quantitative information about significant unobservable inputs in the fair value measurement of level 3 assets) (Details) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	101	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	13.00%	20.00%
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Credit Spread	3.00%	4.00%
Equity securities [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure	16	10
Equity securities [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price	12	360
Equity securities [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price	4,391	4,268
Equity securities [Member] | Market Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Private offering price	600	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	82	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	55.00%	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	1676.00%	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	163.00%	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%

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 $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	$1	$23
Mortgage loans	588	508
Financial Liabilities [Abstract]
Short term debt		549
Long term debt	2,559	2,011
Carrying Amount [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	1	23
Mortgage loans	588	508
Financial Liabilities [Abstract]
Premium deposits and annuity contracts		57
Short term debt		549
Long term debt	2,559	2,011
Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	1	23
Mortgage loans	608	515
Financial Liabilities [Abstract]
Premium deposits and annuity contracts		58
Short term debt		575
Long term debt	2,883	2,328
Level 1 [Member] | Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	0	0
Mortgage loans	0	0
Financial Liabilities [Abstract]
Premium deposits and annuity contracts		0
Short term debt		0
Long term debt	0	0
Level 2 [Member] | Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	0	0
Mortgage loans	0	0
Financial Liabilities [Abstract]
Premium deposits and annuity contracts		0
Short term debt		575
Long term debt	2,883	2,328
Level 3 [Member] | Estimated Fair Value [Member]
Financial Assets [Abstract]
Notes receivable for the issuance of common stock	1	23
Mortgage loans	608	515
Financial Liabilities [Abstract]
Premium deposits and annuity contracts		58
Short term debt		0
Long term debt	$0	$0

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Federal income taxes received from (paid to) Loews	($287,000,000)	($89,000,000)	$75,000,000
Unrecognized tax benefits	0	0
Interest income (expense)	0	0	2,000,000
Unrecognized Tax Benefits, Income Tax Penalties Expense	0	0	0
Accrued interest and penalties	0	0
Deferred tax liabilities not recognized on undistributed earnings	0
Foreign tax expense (benefit) on income from continuing operations	24,000,000	24,000,000	34,000,000
Income (loss) from continuing foreign operations	66,000,000	101,000,000	88,000,000
Tax Credit Carryforward, Amount	0
Valuation allowance	$0	$0

Income_Taxes_Reconciliation_be

Income Taxes (Reconciliation between the Company's federal income tax (expense) benefit at statutory rates and the recorded income tax (expense) benefit) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax expense at statutory rates	($423)	($447)	($301)
Tax benefit from tax exempt income	119	97	84
Foreign taxes and credits	-6	-1	-13
Other tax expense	-9	-10	-9
Income tax (expense) benefit	($319)	($361)	($239)

Income_Taxes_Current_and_defer

Income Taxes (Current and deferred components of the Company's income tax (expense) benefit) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current tax (expense) benefit	($318)	($292)	($94)
Deferred income tax (expense) benefit	-1	-69	-145
Income tax (expense) benefit	($319)	($361)	($239)

Income_Taxes_Significant_compo

Income Taxes (Significant components of the Company's deferred tax assets and liabilities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Deferred Tax Assets:
Property and casualty claim and claim adjustment expense reserves	$265	$289
Unearned premium reserves	187	178
Receivables	35	50
Employee benefits	289	187
Life settlement contracts	46	46
Deferred retroactive reinsurance benefit	61	66
Other assets	138	149
Gross deferred tax assets	1,021	965
Deferred Tax Liabilities:
Investment valuation differences	50	68
Deferred acquisition costs	226	232
Net unrealized gains	489	383
Other liabilities	65	62
Deferred Tax Liabilities, Gross	830	745
Net deferred tax asset (liability)	$191	$220

Claim_and_Claim_Adjustment_Exp2

Claim and Claim Adjustment Expense Reserves (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010
Catastrophe losses net of reinsurance	$156,000,000	$169,000,000	$391,000,000
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development Life & Group	-14,000,000	-9,000,000	-11,000,000
Net Prior Year Claim and Allocated Claim Adjustment Expense Reserve Development, Workers' Compensation Reinsurance Pool	-26,000,000
Loss Portfolio Transfer [Member]
Net A&EP claim and allocated claim adjustment expense reserves ceded to NICO				1,600,000,000
Aggregate limit under A&EP Loss Portfolio Transfer				4,000,000,000
A&EP claim and allocated claim adjustment expense reserves ceded under existing third party reinsurance contracts transferred to NICO under A&EP Loss Portfolio Transfer				1,200,000,000
Reinsurance premium paid to NICO under A&EP Loss Portfolio Transfer				2,000,000,000
Net reinsurance receivables transferrred to NICO under A&EP Loss Portfolio Transfer				215,000,000
Total consideration paid to NICO under AEP Loss Portfolio Transfer				2,200,000,000
Pretax impact of unrecognized deferred retroactive reinsurance benefit	-13,000,000	189,000,000
Deferred reinsurance benefit yet to be recognized	176,000,000
Cumulative amounts ceded under AEP Loss Portfolio Transfer		2,500,000,000
Fair value of collateral trust account established by NICO under A&EP Loss Portfolio Transfer	$3,400,000,000

Claim_and_Claim_Adjustment_Exp3

Claim and Claim Adjustment Expense Reserves (Reconcilliation of claim and claim adjustment expense reserves) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Reserves, beginning of year:
Gross	$24,089		$24,763		$24,303
Ceded	4,972		5,126		5,020
Net reserves, beginning of year	19,117		19,637		19,283
Change in net reserves due to acquisition (disposition) of subsidiaries	-13				291
Net incurred claim and claim adjustment expenses:
Provision for insured events of current year	5,043		5,114		5,273
Decrease in provision for insured events of prior years	-36		-115		-182
Amortization of discount	161		154		145
Total net incurred (a)	5,168	[1]	5,153	[1]	5,236	[1]
Net payments attributable to:
Current year events	-945		-981		-988
Prior year events	-4,355		-4,588		-4,280
Total net payments	-5,300		-5,569		-5,268
Foreign currency translation adjustment and other	-45		-104		95
Net reserves, end of year	18,927		19,117		19,637
Ceded reserves, end of year	4,344		4,972		5,126
Gross reserves, end of year	$23,271		$24,089		$24,763
[1]	Total net incurred above does not agree to Insurance claims and policyholders' benefits as reflected on the Consolidated Statements of Operations due to amounts related to retroactive reinsurance deferred gain accounting, uncollectible reinsurance and loss deductible receivables, and benefit expenses related to future policy benefits and policyholders' funds, which are not reflected in the table above.

Claim_and_Claim_Adjustment_Exp4

Claim and Claim Adjustment Expense Reserves (Net prior year claim and claim adjustment expense reserve development) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Decrease in provision for insured events of prior years	($36)	($115)	($182)
Property and casualty reserve development [Member]
Decrease in provision for insured events of prior years	-39	-115	-180
Life reserve development in life company [Member]
Decrease in provision for insured events of prior years	$3		($2)

Claim_and_Claim_Adjustment_Exp5

Claim and Claim Adjustment Expense Reserves (Gross and net carried claim and claim adjustment expense reserves) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Gross Case Reserves	$12,256	$12,262
Gross IBNR Reserves	11,015	11,827
Total Gross Carried Claim and Claim Adjustment Expense Reserves	23,271	24,089	24,763	24,303
Net Case Reserves	10,190	10,176
Net IBNR Reserves	8,737	8,941
Total Net Carried Claim and Claim Adjustment Expense Reserves	18,927	19,117	19,637	19,283
Specialty [Member]
Gross Case Reserves	2,136	2,001
Gross IBNR Reserves	4,093	4,057
Total Gross Carried Claim and Claim Adjustment Expense Reserves	6,229	6,058
Net Case Reserves	1,929	1,793
Net IBNR Reserves	3,726	3,789
Total Net Carried Claim and Claim Adjustment Expense Reserves	5,655	5,582
Commercial [Member]
Gross Case Reserves	5,298	5,570
Gross IBNR Reserves	4,216	4,521
Total Gross Carried Claim and Claim Adjustment Expense Reserves	9,514	10,091
Net Case Reserves	4,947	5,119
Net IBNR Reserves	3,906	3,992
Total Net Carried Claim and Claim Adjustment Expense Reserves	8,853	9,111
International [Member]
Gross Case Reserves	752	803
Gross IBNR Reserves	689	772
Total Gross Carried Claim and Claim Adjustment Expense Reserves	1,441	1,575
Net Case Reserves	598	629
Net IBNR Reserves	663	705
Total Net Carried Claim and Claim Adjustment Expense Reserves	1,261	1,334
Life and Group Non-Core [Member]
Gross Case Reserves	2,881	2,748
Gross IBNR Reserves	302	310
Total Gross Carried Claim and Claim Adjustment Expense Reserves	3,183	3,058
Net Case Reserves	2,572	2,352
Net IBNR Reserves	271	271
Total Net Carried Claim and Claim Adjustment Expense Reserves	2,843	2,623
Corporate and Other [Member]
Gross Case Reserves	1,189	1,140
Gross IBNR Reserves	1,715	2,167
Total Gross Carried Claim and Claim Adjustment Expense Reserves	2,904	3,307
Net Case Reserves	144	283
Net IBNR Reserves	171	184
Total Net Carried Claim and Claim Adjustment Expense Reserves	$315	$467

Claim_and_Claim_Adjustment_Exp6

Claim and Claim Adjustment Expense Reserves (Net prior year development) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($21)	($118)	($205)
Pretax (favorable) unfavorable premium development, excluding Life & Group	-32	-42	-46
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-53	-160	-251
Specialty [Member]
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	-136	-196	-93
Pretax (favorable) unfavorable premium development, excluding Life & Group	-13	-14	-14
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-149	-210	-107
Commercial [Member]
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	176	122	-25
Pretax (favorable) unfavorable premium development, excluding Life & Group	-20	-8	-36
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	156	114	-61
International [Member]
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	-59	-38	-74
Pretax (favorable) unfavorable premium development, excluding Life & Group	2	-21	3
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-57	-59	-71
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	-2	-6	-13
Pretax (favorable) unfavorable premium development, excluding Life & Group	-1	1	1
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	($3)	($5)	($12)

Claim_and_Claim_Adjustment_Exp7

Claim and Claim Adjustment Expense Reserves (Net prior year claim and allocated claim adjustment expense reserve development for Specialty segment) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($21)	($118)	($205)
Specialty [Member]
Medical Professional Liability	39	-27	-34
Other Professional Liability and Management Liability	-87	-73	19
Surety	-82	-74	-63
Warranty	-2	-3	-5
Other	-4	-19	-10
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($136)	($196)	($93)

Claim_and_Claim_Adjustment_Exp8

Claim and Claim Adjustment Expense Reserves (Net prior year claim and allocated claim adjustment expense reserve development for Commercial segment) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($21)	($118)	($205)
Commercial [Member]
Commercial Auto	31	18	25
General Liability	45	64	-66
Workers' Compensation	139	91	15
Property and Other	-39	-51	1
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	$176	$122	($25)

Claim_and_Claim_Adjustment_Exp9

Claim and Claim Adjustment Expense Reserves Net prior year claim and allocated claim adjustment expense reserve development for International segment (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($21)	($118)	($205)
International [Member]
Medical Professional Liability	-7	-7	1
Other Professional Liability	-26	-30	-41
Liability	-13	-8	-2
Property & Marine	-14	13	-30
Other	-9	-17	-2
Commutations	10	11
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($59)	($38)	($74)

Recovered_Sheet1

Claim and Claim Adjustment Expense Reserves (Impact of Loss Portfolio Transfer on the Consolidated Statement of Operations) (Details) (Loss Portfolio Transfer [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loss Portfolio Transfer [Member]
Net AEP adverse development before consideration of LPT		$363	$261
Provision for uncollectible third-party reinsurance on AEP		140
Additional amounts ceded under LPT		503	261
Retroactive reinsurance benefit recognized	-13	-314	-261
Pretax impact of unrecognized deferred retroactive reinsurance benefit	($13)	$189

Reinsurance_Narrative_Details

Reinsurance (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Funds held under reinsurance agreements, liability	$3,400,000,000	$3,900,000,000
Reinsurance recoveries reported in insurance claims and policyholders' benefits reported on the Consolidated Statement of Operations	1,379,000,000	1,450,000,000	1,443,000,000
Subsidiaries of Berkshire Hathaway Group [Member]
Largest Recoverables From Single Reinsurer	2,565,000,000
Subsidiaries of Hartford Insurance Group [Member]
Largest Recoverables From Single Reinsurer	244,000,000
Subsidiaries of Wilton Re [Member]
Largest Recoverables From Single Reinsurer	185,000,000
Significant Captive Program [Member]
Direct and ceded earned premiums	2,643,000,000	2,156,000,000	1,794,000,000
Reinsurance recoveries reported in insurance claims and policyholders' benefits reported on the Consolidated Statement of Operations	$1,458,000,000	$712,000,000	$814,000,000

Reinsurance_Components_of_Rein

Reinsurance (Components of Reinsurance Receivables) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Reinsurance Disclosures [Abstract]
Ceded claim and claim adjustment expenses	$4,344	$4,972	$5,126	$5,020
Ceded future policy benefits	185	733
Ceded policyholders' funds		35
Reinsurance receivables related to paid losses	213	348
Reinsurance receivables	4,742	6,088
Allowance for uncollectible reinsurance	-48	-71
Reinsurance receivables, net of allowance for uncollectible reinsurance	$4,694	$6,017

Reinsurance_Components_of_Earn

Reinsurance (Components of Earned Premiums) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Direct premiums earned	$9,960	$9,574	$8,866
Assumed premiums earned	325	306	244
Ceded premiums earned	3,073	2,609	2,229
Net earned premiums	7,212	7,271	6,881
Property and Casualty Insurance [Member]
Direct premiums earned	9,452	9,063	8,354
Assumed premiums earned	277	258	197
Ceded premiums earned	3,073	2,609	2,229
Net earned premiums	6,656	6,712	6,322
Accident and Health Insurance [Member]
Direct premiums earned	508	511	512
Assumed premiums earned	48	48	47
Ceded premiums earned	0	0	0
Net earned premiums	$556	$559	$559
Percentage of assumed premiums earned to net premiums earned [Member]
Percentage of assumed premium earned to premium earned net	4.50%	4.20%	3.50%
Percentage of assumed premiums earned to net premiums earned [Member] | Property and Casualty Insurance [Member]
Percentage of assumed premium earned to premium earned net	4.20%	3.80%	3.10%
Percentage of assumed premiums earned to net premiums earned [Member] | Accident and Health Insurance [Member]
Percentage of assumed premium earned to premium earned net	8.60%	8.60%	8.40%

Reinsurance_Components_of_Writ

Reinsurance (Components of Written Premiums) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Direct premiums written	$9,787	$9,608	$8,973
Assumed premiums written	325	296	216
Ceded premiums written	3,024	2,556	2,225
Net written premiums	7,088	7,348	6,964
Property and Casualty Insurance [Member]
Direct premiums written	9,283	9,103	8,467
Assumed premiums written	276	249	169
Ceded premiums written	3,024	2,556	2,225
Net written premiums	6,535	6,796	6,411
Accident and Health Insurance [Member]
Direct premiums written	504	505	506
Assumed premiums written	49	47	47
Ceded premiums written	0	0	0
Net written premiums	$553	$552	$553
Percentage of assumed premiums written to net premiums written [Member]
Percentage of assumed premium written to premium written net	4.60%	4.00%	3.10%
Percentage of assumed premiums written to net premiums written [Member] | Property and Casualty Insurance [Member]
Percentage of assumed premium written to premium written net	4.20%	3.70%	2.60%
Percentage of assumed premiums written to net premiums written [Member] | Accident and Health Insurance [Member]
Percentage of assumed premium written to premium written net	8.90%	8.50%	8.50%

Debt_Narrative_Details

Debt (Narrative) (Details) (USD $)	Dec. 31, 2014
Debt Disclosure [Abstract]
Federal Home Loan Bank Stock	$16,000,000
Federal Home Loan Bank, Advances, General Debt Obligations, Maximum Amount Available	330,000,000
Line of Credit, Current borrowing capacity	250,000,000
Additional borrowing capacity available	100,000,000
Line of Credit, Minimum Net Worth Required for Compliance	$8,600,000,000

Debt_Schedule_of_debt_instrume

Debt (Schedule of debt instruments) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Long term debt	$2,559	$2,011
Total debt	2,559
Debt, Long-term and Short-term, Combined Amount		2,560
Senior notes 6.500%, face amount of $350, due August 15, 2016
Long term debt	349	349
Senior notes 6.950%, face amount $150, due January 15, 2018
Long term debt	150	149
Senior notes 7.350%, face amount $350, due November 15, 2019
Long term debt	348	348
Senior notes 5.875%, face amount $500, due August 15, 2020
Long term debt	497	497
Senior notes 5.750%, face amount $400, due August 15, 2021
Long term debt	397	397
Senior Notes, 3.950%, face amount of $550, due May 15, 2024
Long term debt	547
Debenture of CNAF, 7.250%, face amount of $243, due November 15, 2023
Long term debt	241	241
Subordinated variable rate debt of Hardy, face amount of $30, due September 15, 2036
Long term debt	30	30
Senior notes 5.850%, face amount $549, due December 15, 2014
Short term debt		$549

Debt_Maturity_of_debt_Details

Debt (Maturity of debt) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Debt Disclosure [Abstract]
Repayments of principal in year two	$350
Repayments of principal in year four	150
Repayments of principal in year five	350
Repayments of principal after year five	1,723
Less discount	-14
Total debt	$2,559

Benefit_Plans_Narrative_detail

Benefit Plans (Narrative) (details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Lump sum settlement acceptance rate by retirement plan participants	20.00%
Lump sum pension settlement payment	$253
Settlement loss	84
Curtailment gain	-86
Future capital call commitments for limited partnership investments	327
Document Period End Date	31-Dec-14
Pension Plans, Defined Benefit [Member]
Settlement loss	84	3
Defined benefit plan, accumulated benefit obligation	2,962	2,889
Future capital call commitments for limited partnership investments	107
Limited partnership equity related hedge fund strategy plan assets	57.00%
Limited partnership hedge fund multi strategy plan assets	37.00%
Limited partnership hedge fund strategy distressed investments plan assets	6.00%
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	14
Cost of Living Adjustment [Member]
Assumptions used in calculating assumed health care cost trend rate	4.00%
Employer Subsidy on Health Care Costs [Member]
Assumptions used in calculating assumed health care cost trend rate	4.00%
Other Postretirement Benefit Plan [Member]
Curtailment gain	-86
Defined benefit plan, health care cost trend rate assumed for next fiscal year	4.00%	4.00%	4.00%
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	5
Equity securities [Member]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	40.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	60.00%
Defined Contribution Pension [Member]
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	50.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	70.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%
Defined Contribution Plan, Employers Matching Contribution, Vesting Period in Years	5 years
Company Contribution of Eligible Compensation, Depending on Age, Percent	3% or 5%
Benefit expense for the Company's savings plan	$69	71	70
First Year of Employment [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	35.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%
Additional Contribution, Management Discretion [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	80.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%
Defined Contribution Plan, Employers Matching Contribution, Vesting Period in Years	5 years
Defined Contribution Plan, Employer Discretionary Contribution Amount, Percent	2.00%

Benefit_Plans_Funded_Status_De

Benefit Plans (Funded Status) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at January 1	$2,943	$3,271
Service cost	9	12	12
Interest cost	132	121	135
Participants' contributions	0	0
Plan amendments	-3	0
Actuarial (gain) loss	367	-289
Benefits paid	-165	-165
Settlements	-257	-8
Foreign currency translation and other	-7	1
Benefit obligation at December 31	3,019	2,943	3,271
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at January 1	2,656	2,425
Actual return on plan assets	216	311
Company contributions	12	92
Participants' contributions	0	0
Benefits paid	-165	-165
Settlements	-257	-8
Foreign currency translation and other	-6	1
Fair value of plan assets at December 31	2,456	2,656	2,425
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded status	-563	-287
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Other assets	9	9
Other liabilities	-572	-296
Net amount recognized on balance sheets	-563	-287
Amounts recognized in Accumulated other comprehensive income not yet recognized in net periodic cost (benefit)[Abstract]
Prior service credit	0	0
Net actuarial (gain) loss	974	745
Net amount recognized in Accumulated other comprehensive income	974	745
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at January 1	40	47
Service cost	0	1	0
Interest cost	1	1	2
Participants' contributions	5	5
Plan amendments	-7	0
Actuarial (gain) loss	1	-3
Benefits paid	-11	-12
Settlements	0	0
Foreign currency translation and other	0	1
Benefit obligation at December 31	29	40	47
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at January 1	0	0
Actual return on plan assets	0	0
Company contributions	6	7
Participants' contributions	5	5
Benefits paid	-11	-12
Settlements	0	0
Foreign currency translation and other	0	0
Fair value of plan assets at December 31	0	0	0
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded status	-29	-40
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Other assets	0	0
Other liabilities	-29	-40
Net amount recognized on balance sheets	-29	-40
Amounts recognized in Accumulated other comprehensive income not yet recognized in net periodic cost (benefit)[Abstract]
Prior service credit	-9	-98
Net actuarial (gain) loss	8	8
Net amount recognized in Accumulated other comprehensive income	($1)	($90)

Benefit_Plans_Components_of_ne

Benefit Plans (Components of net periodic cost (benefit)) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Curtailment gain	($86)
Settlement loss	84
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	9	12	12
Interest cost on projected benefit obligation	132	121	135
Expected return on plan assets	-191	-181	-171
Amortization of net actuarial (gain) loss	25	47	39
Settlement loss	84	3
Net periodic (benefit) cost	59	2	15
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	1	0
Interest cost on projected benefit obligation	1	1	2
Amortization of prior service credit	-10	-18	-18
Amortization of net actuarial (gain) loss	1	2	1
Curtailment gain	-86
Net periodic (benefit) cost	($94)	($14)	($15)

Benefit_Plans_Schedule_of_amou

Benefit Plans (Schedule of amounts recognized in Other comprehensive income) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, [Abstract]
Amounts arising during the period	($337)	$422	($195)
Curtailment and other	-81	0	0
Settlement	84	0	0
Reclassification adjustment relating to prior service cost (credit)	-10	-18	-18
Reclassification adjustment relating to actuarial (gain) loss	26	49	40
Total increase (decrease) in Other comprehensive income	($318)	$453	($173)

Benefit_Plans_Schedule_of_esti

Benefit Plans (Schedule of estimated amounts to be recognized from Accumulated other comprehensive income into net periodic cost (benefit) during next fiscal year) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2015
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost (credit)	$0
Amortization of net actuarial (gain) loss	38
Total estimated amounts to be recognized	38
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost (credit)	-2
Amortization of net actuarial (gain) loss	1
Total estimated amounts to be recognized	($1)

Benefit_Plans_Actuarial_Assump

Benefit Plans (Actuarial Assumptions for Benefit Obligations) (Details)	Dec. 31, 2014	Dec. 31, 2013
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.85%	4.65%
Expected long term rate of return	7.50%	7.50%
Rate of compensation increases	3.92%	3.99%
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.50%	3.60%

Benefit_Plans_Actuarial_Assump1

Benefit Plans (Actuarial Assumptions for Net Cost or Benefit) (Details)	12 Months Ended			6 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Jun. 30, 2014
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.65%	3.80%	4.60%
Expected long term rate of return	7.50%	7.75%	8.00%
Rate of compensation increases	3.99%	4.07%	4.13%
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate		2.80%	3.75%	3.10%	3.60%

Benefit_Plans_Fair_Value_of_Pl

Benefit Plans (Fair Value of Plan Assets Measured on a Recurring Basis) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Document Period End Date	31-Dec-14
Corporate and other bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	478	$520
Corporate and other bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Corporate and other bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	463	505
Corporate and other bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15	15	11
States, municipalities and political subdivisions [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	80	73
States, municipalities and political subdivisions [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
States, municipalities and political subdivisions [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	80	73
States, municipalities and political subdivisions [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Residential mortgage-backed [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	123	130
Residential mortgage-backed [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Residential mortgage-backed [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	123	130
Residential mortgage-backed [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Commercial Mortgage Backed Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	75	106
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	75	106
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other asset-backed [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	12
Other asset-backed [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other asset-backed [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	12
Other asset-backed [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Total asset-backed [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	210	248
Total asset-backed [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Total asset-backed [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	210	248
Total asset-backed [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. Treasury and obligations of government-sponsored enterprises [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25
U.S. Treasury and obligations of government-sponsored enterprises [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25
U.S. Treasury and obligations of government-sponsored enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
U.S. Treasury and obligations of government-sponsored enterprises [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Fixed Maturities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	793	841
Fixed Maturities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25	0
Fixed Maturities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	753	826
Fixed Maturities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15	15	11
Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	507	605
Equity securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	389	480
Equity securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	118	117
Equity securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	8	5
Derivative Financial Instruments, Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	2
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	2
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Short-term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	134	94
Short-term Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	33	45
Short-term Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	101	49
Short-term Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	865	969
Hedge Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Hedge Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	562	647
Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	303	322	359
Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	113	114
Private Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Private Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Private Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	113	114	62
Total limited partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	978	1,083
Total limited partnerships [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Total limited partnerships [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	562	647
Total limited partnerships [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	416	436	421
Other assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	30	31
Other assets [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other assets [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	30	31
Other assets [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13
Cash [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13
Cash [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Cash [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Total assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,456	2,656
Total assets [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	461	527
Total assets [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,564	1,670
Total assets [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	431	$459	$447

Benefit_Plans_Reconciliation_o

Benefit Plans (Reconciliation of Level 3 Plan Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Corporate and other bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at December 31	$478	$520
Fixed Maturities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at December 31	793	841
Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at December 31	507	605
Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at December 31	865	969
Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at December 31	113	114
Total limited partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at December 31	978	1,083
Total assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at December 31	2,456	2,656
Fair Value, Inputs, Level 3 [Member] | Corporate and other bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at January 1	15	11
Defined Benefit Plan, Actual Return on Plan Assets Still Held	0	-1
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	0
Defined Benefit Plan, Purchases, Sales, and Settlements	0	5
Defined Benefit Plan, Net transfers into (out of) Level 3	0	0
Fair value of plan assets at December 31	15	15
Fair Value, Inputs, Level 3 [Member] | Fixed Maturities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at January 1	15	11
Defined Benefit Plan, Actual Return on Plan Assets Still Held	0	-1
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	0
Defined Benefit Plan, Purchases, Sales, and Settlements	0	5
Defined Benefit Plan, Net transfers into (out of) Level 3	0	0
Fair value of plan assets at December 31	15	15
Fair Value, Inputs, Level 3 [Member] | Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at January 1	8	5
Defined Benefit Plan, Actual Return on Plan Assets Still Held	0	3
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	0
Defined Benefit Plan, Purchases, Sales, and Settlements	-8	0
Defined Benefit Plan, Net transfers into (out of) Level 3	0	0
Fair value of plan assets at December 31	0	8
Fair Value, Inputs, Level 3 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at January 1	322	359
Defined Benefit Plan, Actual Return on Plan Assets Still Held	19	56
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	0
Defined Benefit Plan, Purchases, Sales, and Settlements	-38	-77
Defined Benefit Plan, Net transfers into (out of) Level 3	0	-16
Fair value of plan assets at December 31	303	322
Fair Value, Inputs, Level 3 [Member] | Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at January 1	114	62
Defined Benefit Plan, Actual Return on Plan Assets Still Held	19	0
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	0
Defined Benefit Plan, Purchases, Sales, and Settlements	-20	52
Defined Benefit Plan, Net transfers into (out of) Level 3	0	0
Fair value of plan assets at December 31	113	114
Fair Value, Inputs, Level 3 [Member] | Total limited partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at January 1	436	421
Defined Benefit Plan, Actual Return on Plan Assets Still Held	38	56
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	0
Defined Benefit Plan, Purchases, Sales, and Settlements	-58	-25
Defined Benefit Plan, Net transfers into (out of) Level 3	0	-16
Fair value of plan assets at December 31	416	436
Fair Value, Inputs, Level 3 [Member] | Investment Contracts with Insurance Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at January 1		10
Defined Benefit Plan, Actual Return on Plan Assets Still Held		0
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period		0
Defined Benefit Plan, Purchases, Sales, and Settlements		-10
Defined Benefit Plan, Net transfers into (out of) Level 3		0
Fair value of plan assets at December 31		0
Fair Value, Inputs, Level 3 [Member] | Total assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at January 1	459	447
Defined Benefit Plan, Actual Return on Plan Assets Still Held	38	58
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	0
Defined Benefit Plan, Purchases, Sales, and Settlements	-66	-30
Defined Benefit Plan, Net transfers into (out of) Level 3	0	-16
Fair value of plan assets at December 31	$431	$459

Benefit_Plans_Estimated_Future

Benefit Plans (Estimated Future Minimum Benefit Payments to Participants) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	$179
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	181
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	180
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	184
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	185
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	936
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	5
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	4
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	4
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	4
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	3
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	$9

StockBased_Compensation_Narrat

Stock-Based Compensation (Narrative) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	6,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	1,500,000
Allocated Share-based Compensation Expense	$11	$10	$9
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	4	3	3
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	13
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 8 months 15 days
Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period Following Date of Grant, in Years	4
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period Following Date of Grant, in Years	4
Range of Shares Initially Granted Payable Based Upon Attainment of Specific Annual Performance Goals	0% to 100%
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Shares Initially Granted Payable Based Upon Attainment of Specific Annual Performance Goals	0% to 200%
Measurement Period of Specific Annual Performance Goals, in Years	3
Stock Options and SARs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period Following Date of Grant, in Years	4
Stock Options and SARs, Maximum Term Following Date of Grant, in Years	10
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0	0	10,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	1,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number	1,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	1,000,000
Fair Value of Stock Based Awards Vested	$1	$1	$1

StockBased_Compensation_Restri

Stock-Based Compensation (Restricted shares, performance-based restricted share units and performance share unit activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of nonvested awards at January 1	847,674
Weighted average grant date fair value of nonvested awards at January 1	$29.61
Number of awards granted	261,273
Weighted average grant date fair value of awards granted	$41.01
Number of awards vested	-156,332
Weighted average grant date fair value of awards vested	$28.42
Number of awards forfeited, canceled or expired	-91,002
Weighted average grant date fair value of awards forfeited, canceled or expired	$32.09
Performance-based adjustment	52,568
Weighted average grant date fair value of performance based adjustment	$28.50
Number of nonvested awards at December 31	914,181
Weighted average grant date fair value of nonvested awards at December 31	$32.76

Schedule_of_Other_Intangible_A

Schedule of Other Intangible Assets (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Amortization of deferred acquisition costs	$1,317	$1,362	$1,274
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	1
Finite-Lived Intangible Assets, Amortization Expense, Year Two	2
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
International [Member]
Amortization of deferred acquisition costs	204	223	152	[1]
Other Intangible Assets [Member] | International [Member]
Amortization of deferred acquisition costs	2	15	33
Amortization expense included in other operating expenses	$1	$5	$10
[1]	International includes Hardy from the date of acquisition.

Schedule_of_Other_Intangible_A1

Schedule of Other Intangible Assets (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Indefinite-lived intangible assets	$71	$74
Finite-Lived Intangible Assets	80	85
Intangible Assets, Gross (Excluding Goodwill)	151	159
Accumulated Amortization	66	66
Lloyds syndicate capacity [Member]
Indefinite-lived intangible assets	55	58
Agency Force [Member]
Indefinite-lived intangible assets	16	16
Value of business acquired [Member]
Finite-Lived Intangible Assets	60	64
Accumulated Amortization	61	63
Trade name [Member]
Economic useful life measured in years	8 years
Finite-Lived Intangible Assets	8	8
Accumulated Amortization	3	2
Distribution channel [Member]
Economic useful life measured in years	15 years
Finite-Lived Intangible Assets	12	13
Accumulated Amortization	$2	$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

Operating_Leases_Commitments_a2

Operating Leases, Commitments and Contingencies, and Guarantees (Narrative) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$1,900
Operating Leases, Rent Expense	55	46	52
Operating Leases, Income Statement, Sublease Revenue	1	3	2
Guarantee Obligations [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	375
Indemnification Agreement [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	324
Property Lease Guarantee [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$50

Operating_Leases_Commitments_a3

Operating Leases, Commitments and Contingencies, and Guarantees (Future Minimum Lease Payments and Sublease Receipts) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Operating Leases, Commitments and Contingencies, and Guarantees [Abstract]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$36
Operating Leases, Future Minimum Payments, Due in Two Years	35
Operating Leases, Future Minimum Payments, Due in Three Years	30
Operating Leases, Future Minimum Payments, Due in Four Years	25
Operating Leases, Future Minimum Payments, Due in Five Years	21
Operating Leases, Future Minimum Payments, Due Thereafter	98
Operating Leases, Future Minimum Payments Due	245
Operating Leases, Future Minimum Payments Receivable, in Five Years	1
Operating Leases, Future Minimum Payments Receivable, Thereafter	1
Operating Leases, Future Minimum Payments Receivable	$2

Stockholders_Equity_and_Statut2

Stockholders' Equity and Statutory Accounting Practices (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Capital Required for Capital Adequacy to Risk Weighted Assets	270.00%	265.00%
Dividends payable without prior supervisory approval	$466
Hardy [Member]
Capital provided by CCC	$105

Stockholders_Equity_and_Statut3

Stockholders' Equity and Statutory Accounting Practices Combined statutory capital and surplus and net income (loss) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Combined Continental Casualty Companies [Member]
Statutory Accounting Practices [Line Items]
Statutory capital and surplus	$11,155	$11,137
Statutory net income (loss)	914	913	391
Life Company [Member]
Statutory Accounting Practices [Line Items]
Statutory capital and surplus		597
Statutory net income (loss)	$37	$48	$44

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) by Component (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	$442	$831
Change due to sale of subsidiaries	0
Other comprehensive income (loss), before reclassifications	8	-388
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	50	1
Other comprehensive income (loss) after tax (expense) benefit	-42	-389
Accumulated other comprehensive income (loss), ending balance	400	442
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	-26	1
Tax (expense) benefit on other comprehensive income (loss)	-4	203
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
Change due to sale of subsidiaries	-5
Other comprehensive income (loss), before reclassifications	15	6
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	0	0
Other comprehensive income (loss) after tax (expense) benefit	15	6
Accumulated other comprehensive income (loss), ending balance	36	26
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	0	0
Tax (expense) benefit on other comprehensive income (loss)	-8	-3
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
Change due to sale of subsidiaries	-17
Other comprehensive income (loss), before reclassifications	295	-658
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	28	21
Other comprehensive income (loss) after tax (expense) benefit	267	-679
Accumulated other comprehensive income (loss), ending balance	942	692
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	-10	-10
Tax (expense) benefit on other comprehensive income (loss)	-122	364
Accumulated Net Unrealized Gains Losses on discontinued operations [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	0
Change due to sale of subsidiaries	22
Other comprehensive income (loss), before reclassifications	12
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	34
Other comprehensive income (loss) after tax (expense) benefit	-22
Accumulated other comprehensive income (loss), ending balance	0
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	-23
Tax (expense) benefit on other comprehensive income (loss)	15
Pension and postretirement benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	-426	-721
Change due to sale of subsidiaries	0
Other comprehensive income (loss), before reclassifications	-219	275
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	-12	-20
Other comprehensive income (loss) after tax (expense) benefit	-207	295
Accumulated other comprehensive income (loss), ending balance	-633	-426
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	7	11
Tax (expense) benefit on other comprehensive income (loss)	111	-158
Cumulative foreign currency translation adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	150	161
Change due to sale of subsidiaries	0
Other comprehensive income (loss), before reclassifications	-95	-11
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	0	0
Other comprehensive income (loss) after tax (expense) benefit	-95	-11
Accumulated other comprehensive income (loss), ending balance	55	150
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	0	0
Tax (expense) benefit on other comprehensive income (loss)	$0	$0

Business_Segments_Narrative_De

Business Segments (Narrative) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business Segments [Abstract]
Percentage of direct foreign written premiums	8.80%	9.00%	9.20%

Business_Segments_Income_State

Business Segments (Income Statement Information) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Net written premiums	$7,088	$7,348	$6,964
Operating Revenues
Net earned premiums	7,212	7,271	6,881
Net investment income	2,067	2,282	2,110
Other revenues	356	359	319
Total operating revenues	9,635	9,912	9,310
Claims, Benefits and Expenses
Net incurred claims and benefits	5,577	5,793	5,716
Policyholders' dividends	14	13	13
Amortization of deferred acquisition costs	1,317	1,362	1,274
Other insurance related expenses	1,029	1,013	1,047
Other expenses	548	475	455
Total claims, benefits and expenses	8,485	8,656	8,505
Operating income (loss) from continuing operations before income tax	1,150	1,256	805
Income tax (expense) benefit on operating income (loss)	-301	-355	-220
Net operating income (loss) from continuing operations	849	901	585
Net realized investment gains (losses), pre-tax	57	20	54
Income tax (expense) benefit on net realized investment gains (losses)	-18	-6	-19
Net realized investment gains (losses), after tax	39	14	35
Net income (loss) from continuing operations	888	915	620
Specialty [Member]
Segment Reporting Information [Line Items]
Net written premiums	2,839	2,880	2,733
Operating Revenues
Net earned premiums	2,838	2,795	2,709
Net investment income	560	629	564
Other revenues	295	257	231
Total operating revenues	3,693	3,681	3,504
Claims, Benefits and Expenses
Net incurred claims and benefits	1,627	1,593	1,746
Policyholders' dividends	6	6	2
Amortization of deferred acquisition costs	592	585	574
Other insurance related expenses	262	250	278
Other expenses	254	237	207
Total claims, benefits and expenses	2,741	2,671	2,807
Operating income (loss) from continuing operations before income tax	952	1,010	697
Income tax (expense) benefit on operating income (loss)	-318	-342	-235
Net operating income (loss) from continuing operations	634	668	462
Net realized investment gains (losses), pre-tax	15	-5	18
Income tax (expense) benefit on net realized investment gains (losses)	-5	2	-8
Net realized investment gains (losses), after tax	10	-3	10
Net income (loss) from continuing operations	644	665	472
Commercial [Member]
Segment Reporting Information [Line Items]
Net written premiums	2,817	2,960	3,033
Operating Revenues
Net earned premiums	2,906	3,004	2,968
Net investment income	723	899	826
Other revenues	38	96	41
Total operating revenues	3,667	3,999	3,835
Claims, Benefits and Expenses
Net incurred claims and benefits	2,187	2,259	2,370
Policyholders' dividends	8	7	11
Amortization of deferred acquisition costs	493	526	520
Other insurance related expenses	487	498	532
Other expenses	31	32	37
Total claims, benefits and expenses	3,206	3,322	3,470
Operating income (loss) from continuing operations before income tax	461	677	365
Income tax (expense) benefit on operating income (loss)	-154	-229	-120
Net operating income (loss) from continuing operations	307	448	245
Net realized investment gains (losses), pre-tax	16	-15	34
Income tax (expense) benefit on net realized investment gains (losses)	-6	5	-11
Net realized investment gains (losses), after tax	10	-10	23
Net income (loss) from continuing operations	317	438	268
International [Member]
Segment Reporting Information [Line Items]
Net written premiums	880	959	648	[1]
Operating Revenues
Net earned premiums	913	916	647	[1]
Net investment income	61	60	59	[1]
Other revenues	0	0	-1	[1]
Total operating revenues	974	976	705	[1]
Claims, Benefits and Expenses
Net incurred claims and benefits	488	489	361	[1]
Policyholders' dividends	0	0	0	[1]
Amortization of deferred acquisition costs	204	223	152	[1]
Other insurance related expenses	151	140	94	[1]
Other expenses	28	12	7	[1]
Total claims, benefits and expenses	871	864	614	[1]
Operating income (loss) from continuing operations before income tax	103	112	91	[1]
Income tax (expense) benefit on operating income (loss)	-34	-43	-40	[1]
Net operating income (loss) from continuing operations	69	69	51	[1]
Net realized investment gains (losses), pre-tax	-1	5	7	[1]
Income tax (expense) benefit on net realized investment gains (losses)	1	-2	-1	[1]
Net realized investment gains (losses), after tax	0	3	6	[1]
Net income (loss) from continuing operations	69	72	57	[1]
Life and Group Non-Core [Member]
Segment Reporting Information [Line Items]
Net written premiums	553	552	553
Operating Revenues
Net earned premiums	556	559	559
Net investment income	700	662	629
Other revenues	16	-4	33
Total operating revenues	1,272	1,217	1,221
Claims, Benefits and Expenses
Net incurred claims and benefits	1,304	1,261	1,255
Policyholders' dividends	0	0	0
Amortization of deferred acquisition costs	28	28	28
Other insurance related expenses	130	130	142
Other expenses	30	13	22
Total claims, benefits and expenses	1,492	1,432	1,447
Operating income (loss) from continuing operations before income tax	-220	-215	-226
Income tax (expense) benefit on operating income (loss)	151	141	134
Net operating income (loss) from continuing operations	-69	-74	-92
Net realized investment gains (losses), pre-tax	7	26	-9
Income tax (expense) benefit on net realized investment gains (losses)	0	-8	3
Net realized investment gains (losses), after tax	7	18	-6
Net income (loss) from continuing operations	-62	-56	-98
Corporate and Other Non-Core [Member]
Segment Reporting Information [Line Items]
Net written premiums	1	-1	-1
Operating Revenues
Net earned premiums	1	-1	0
Net investment income	23	32	32
Other revenues	12	12	16
Total operating revenues	36	43	48
Claims, Benefits and Expenses
Net incurred claims and benefits	-29	191	-16
Policyholders' dividends	0	0	0
Amortization of deferred acquisition costs	0	0	0
Other insurance related expenses	1	-3	3
Other expenses	210	183	183
Total claims, benefits and expenses	182	371	170
Operating income (loss) from continuing operations before income tax	-146	-328	-122
Income tax (expense) benefit on operating income (loss)	54	118	41
Net operating income (loss) from continuing operations	-92	-210	-81
Net realized investment gains (losses), pre-tax	20	9	4
Income tax (expense) benefit on net realized investment gains (losses)	-8	-3	-2
Net realized investment gains (losses), after tax	12	6	2
Net income (loss) from continuing operations	-80	-204	-79
Eliminations [Member]
Segment Reporting Information [Line Items]
Net written premiums	-2	-2	-2
Operating Revenues
Net earned premiums	-2	-2	-2
Net investment income	0	0	0
Other revenues	-5	-2	-1
Total operating revenues	-7	-4	-3
Claims, Benefits and Expenses
Net incurred claims and benefits	0	0	0
Policyholders' dividends	0	0	0
Amortization of deferred acquisition costs	0	0	0
Other insurance related expenses	-2	-2	-2
Other expenses	-5	-2	-1
Total claims, benefits and expenses	-7	-4	-3
Operating income (loss) from continuing operations before income tax	0	0	0
Income tax (expense) benefit on operating income (loss)	0	0	0
Net operating income (loss) from continuing operations		0	0
Net realized investment gains (losses), pre-tax	0	0	0
Income tax (expense) benefit on net realized investment gains (losses)	0	0	0
Net realized investment gains (losses), after tax	0	0	0
Net income (loss) from continuing operations	$0	$0	$0
[1]	International includes Hardy from the date of acquisition.

Business_Segments_Balance_Shee

Business Segments (Balance Sheet Information) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Segment Reporting Information [Line Items]
Reinsurance receivables	$4,742	$6,088
Insurance receivables	1,997	2,063
Deferred acquisition costs	600	624
Goodwill	152	155
Insurance reserves
Claim and claim adjustment expenses	23,271	24,089
Unearned premiums	3,592	3,718
Future policy benefits	9,490	10,471
Policyholders’ funds	27	116
Specialty [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	567	500
Insurance receivables	778	732
Deferred acquisition costs	304	299
Goodwill	117	117
Insurance reserves
Claim and claim adjustment expenses	6,229	6,058
Unearned premiums	1,763	1,710
Future policy benefits	0	0
Policyholders’ funds	9	9
Commercial [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	690	1,024
Insurance receivables	954	1,019
Deferred acquisition costs	213	226
Goodwill	0	0
Insurance reserves
Claim and claim adjustment expenses	9,514	10,091
Unearned premiums	1,273	1,374
Future policy benefits	0	0
Policyholders’ funds	18	15
International [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	207	294
Insurance receivables	250	299
Deferred acquisition costs	83	99
Goodwill	35	38
Insurance reserves
Claim and claim adjustment expenses	1,441	1,575
Unearned premiums	431	506
Future policy benefits	0	0
Policyholders’ funds	0	0
Life and Group Non-Core [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	525	1,203
Insurance receivables	13	11
Deferred acquisition costs	0	0
Goodwill	0	0
Insurance reserves
Claim and claim adjustment expenses	3,183	3,058
Unearned premiums	125	128
Future policy benefits	9,490	10,471
Policyholders’ funds	0	92
Corporate and Other Non-Core [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	2,753	3,067
Insurance receivables	2	2
Deferred acquisition costs	0	0
Goodwill	0	0
Insurance reserves
Claim and claim adjustment expenses	2,904	3,307
Unearned premiums	0	0
Future policy benefits	0	0
Policyholders’ funds	0	0
Eliminations [Member]
Segment Reporting Information [Line Items]
Reinsurance receivables	0	0
Insurance receivables	0	0
Deferred acquisition costs	0	0
Goodwill	0	0
Insurance reserves
Claim and claim adjustment expenses	0	0
Unearned premiums	0	0
Future policy benefits	0	0
Policyholders’ funds	$0	$0

Business_Segments_Revenues_by_

Business Segments (Revenues by Line of Business) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues	$2,378	$2,411	$2,440	$2,463	$2,569	$2,458	$2,450	$2,455	$9,692	$9,932	$9,364
Specialty [Domain]
Revenues									3,708	3,676	3,522
Management & Professional Liability [Member]
Revenues									2,818	2,836	2,723
Surety [Member]
Revenues									509	490	485
Warranty & Alternative Risks [Member]
Revenues									381	350	314
Commercial [Domain]
Revenues									3,683	3,984	3,869
Middle Markets [Member]
Revenues									1,631	1,642	1,560
Small Business [Member]
Revenues									709	754	669
Other Commercial Insurance [Member]
Revenues									1,343	1,588	1,640
International [Domain]
Revenues									973	981	712
Canada [Member]
Revenues									273	289	276
CNA Europe [Member]
Revenues									335	326	313
Hardy [Member]
Revenues									365	366	123
Life and Group Non-Core [Member]
Revenues									1,279	1,243	1,212
Corporate and Other Non-Core [Member]
Revenues									56	52	52
Eliminations [Member]
Revenues									($7)	($4)	($3)

Discontinued_Operations_Income

Discontinued Operations Income Statement Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues
Net Earned Premium			$1
Net Investment Income	94	168	172
Net Realized Investment Gains (Losses)	3	11	9
Other Revenues		2	1
Total Revenues	97	181	183
Claims, Benefits and Expenses
Insurance Claims and Policyholders' Benefits	75	141	167
Other Operating Expenses	2	3	3
Total Claims, Benefits and Expenses	77	144	170
Income before Income Tax	20	37	13
Income tax (expense) benefit	-6	-15	-5
Income from operations of discontinued operations, net of income tax	14	22	8
Loss on sale, net of income tax (expense) benefit of $40, - and -	-211
Income (Loss) from Discontinued Operations	-197	22	8
Income tax benefit (expense) on impairment	$40

Discontinued_Operations_Narrat

Discontinued Operations (Narrative) (Details) (USD $)	Aug. 01, 2014
In Millions, unless otherwise specified
Discontinued Operations and Disposal Groups [Abstract]
Disposal Group, Including Discontinued Operation, Assets	$3,550
Disposal Group, Including Discontinued Operation, Liabilities	$3,297

Quarterly_Financial_Data_Unaud2

Quarterly Financial Data (Unaudited) (Details) (USD $)	3 Months Ended																12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Quarterly Financial Data [Abstract]
Revenues	$2,378		$2,411		$2,440		$2,463		$2,569		$2,458		$2,450		$2,455		$9,692		$9,932		$9,364
Net income (loss)	$198	[1]	$213	[1]	$267	[1]	$13	[1]	$221		$272		$194		$250		$691	[1]	$937		$628
Basic earnings (loss) per share	$0.73		$0.79		$0.99		$0.05		$0.82		$1.01		$0.72		$0.93		$2.56		$3.48		$2.33
Diluted earnings (loss) per share	$0.73		$0.79		$0.98		$0.05		$0.82	[2]	$1.01	[2]	$0.72	[2]	$0.93	[2]	$2.55		$3.47	[2]	$2.33
[1]	Net income in the first quarter of 2014 includes the impairment loss on the sale of CAC.
[2]	Due to the averaging of shares, quarterly earnings per share do not add to the total for the full year.

Related_Party_Transactions_Nar

Related Party Transactions Narrative (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Due to Related Parties	$153	$197
Fees and expenses of investment facilities and services [Member]
Amounts reimbursed to Loews for services provided to the Company	39	37	36
Due to Related Parties	21	19
Loews [Member]
Amounts earned from Loews for insurance premiums	2	2	2
Corporate Services and Related Travel Expenses [Member]
Amounts reimbursed to Loews for services provided to the Company		4	4
Taxes paid [Member]
Due to Related Parties	$132	$178

Schedule_II_Condensed_Financia1

Schedule II. Condensed Financial Information of Registrant (Parent Company) (Schedule of Condensed Financial Information of Registrant, Statements of Operations and Comprehensive Income) (Details) (USD $)	3 Months Ended												12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Revenues
Net realized investment gains (losses)													$57		$20	$54
Other revenues													356		359	319
Total revenues	2,378		2,411		2,440		2,463		2,569	2,458	2,450	2,455	9,692		9,932	9,364
Claims, Benefits and Expenses
Interest													183		166	170
Income tax expense (benefit)													-319		-361	-239
Net income (loss)	198	[1]	213	[1]	267	[1]	13	[1]	221	272	194	250	691	[1]	937	628
Total comprehensive income (loss)													649		548	979
Parent Company [Member]
Revenues
Net investment income													1		1	1
Net realized investment gains (losses)													4		4	4
Other revenues																9
Total revenues													5		5	14
Claims, Benefits and Expenses
Administrative and general													5		-7	1
Interest													182		165	164
Total expenses													187		158	165
Income (loss) from operations before income taxes and equity in net income of subsidiaries													-182		-153	-151
Income tax expense (benefit)													35		22	144
Income (loss) before equity in net income (loss) of subsidiaries													-147		-131	-7
Equity in net income of subsidiaries													838		1,068	635
Net income (loss)													691		937	628
Equity in other comprehensive income of subsidiaries													-42		-389	351
Total comprehensive income (loss)													$649		$548	$979
[1]	Net income in the first quarter of 2014 includes the impairment loss on the sale of CAC.

Schedule_II_Condensed_Financia2

Schedule II. Condensed Financial Information of Registrant (Parent Company) (Schedule of Condensed Financial Information of Registrant, Balance Sheets) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, except Share data, unless otherwise specified
Assets
Cash	$190	$195	$156	$75
Fixed maturity securities available-for-sale, at fair value (amortized cost of $1 and $1)	40,749	41,197
Short term investments	1,706	1,407
Other assets	841	969
Total assets	55,566	57,194
Liabilities
Short term debt		549
Long term debt	2,559	2,011
Other liabilities	3,833	3,408
Total liabilities	42,772	44,543
Stockholders' Equity
Common stock ($2.50 par value; 500,000,000 shares authorized; 273,040,243 shares issued; 269,980,202 and 269,717,583 shares outstanding)	683	683
Additional paid-in capital	2,151	2,145
Retained earnings	9,645	9,495
Accumulated other comprehensive income (loss)	400	442	831
Treasury stock (3,060,041 and 3,322,660 shares), at cost	-84	-91
Notes receivable for the issuance of common stock	-1	-23
Total stockholders’ equity	12,794	12,651	12,314
Total liabilities and stockholders' equity	55,566	57,194
Balance Sheet Parenthetical
Marketable securities fixed maturities available-for-sale at amortized cost basis	37,316	39,275
Common stock, par value	$0	$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	269,980,202	269,717,583
Treasury stock, shares	3,060,041	3,322,660
Parent Company [Member]
Assets
Investment in subsidiaries	14,867	14,708
Cash	1	1
Fixed maturity securities available-for-sale, at fair value (amortized cost of $1 and $1)	1	1
Short term investments	499	505
Amounts due from subsidiaries		3
Other assets	3	3
Total assets	15,371	15,221
Liabilities
Short term debt		549
Long term debt	2,529	1,981
Other liabilities	48	40
Total liabilities	2,577	2,570
Stockholders' Equity
Common stock ($2.50 par value; 500,000,000 shares authorized; 273,040,243 shares issued; 269,980,202 and 269,717,583 shares outstanding)	683	683
Additional paid-in capital	2,151	2,145
Retained earnings	9,645	9,495
Accumulated other comprehensive income (loss)	400	442
Treasury stock (3,060,041 and 3,322,660 shares), at cost	-84	-91
Notes receivable for the issuance of common stock	-1	-23
Total stockholders’ equity	12,794	12,651
Total liabilities and stockholders' equity	15,371	15,221
Balance Sheet Parenthetical
Marketable securities fixed maturities available-for-sale at amortized cost basis	$1	$1
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	269,980,202	269,717,583
Treasury stock, shares	3,060,041	3,322,660

Schedule_II_Condensed_Financia3

Schedule II. Condensed Financial Information of Registrant (Parent Company) (Schedule of Condensed Financial Information of Registrant, Statements of Cash Flows) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Cash Flows from Operating Activities
Net income (loss)	$691	[1]	$937	$628
Adjustments to reconcile net income (loss) to net cash flows provided (used) by operating activities:
Net realized investment (gains) losses	-57		-20	-54
Other, net	54		10	18
Total adjustments	749		267	622
Net cash flows provided (used) by operating activities	1,440		1,204	1,250
Cash Flows from Investing Activities
Change in short term investments	-388		425	-7
Other, net	16		11	16
Net cash flows provided (used) by investing activities	-918		-898	-934
Cash Flows from Financing Activities
Dividends paid to common stockholders	-541		-216	-162
Proceeds from the issuance of debt	546
Repayment of debt	-549		-13	-70
Other, net	25		-35	-7
Net cash flows provided (used) by financing activities	-519		-264	-239
Net change in cash	-5		39	81
Cash, beginning of year	195		156	75
Cash, end of year	190		195	156
Parent Company [Member]
Cash Flows from Operating Activities
Net income (loss)	691		937	628
Adjustments to reconcile net income (loss) to net cash flows provided (used) by operating activities:
Equity in net income (loss) of subsidiaries	-838		-1,068	-635
Dividends received from subsidiaries	650		400	450
Net realized investment (gains) losses	-4		-4	-4
Other, net	14		8	19
Total adjustments	-178		-664	-170
Net cash flows provided (used) by operating activities	513		273	458
Cash Flows from Investing Activities
Proceeds from fixed maturity securities			1	1
Change in short term investments	6		-57	-156
Capital contributions to subsidiaries	-10		-12	-399
Repayment of surplus note by subsidiary				250
Other, net	5		4	4
Net cash flows provided (used) by investing activities	1		-64	-300
Cash Flows from Financing Activities
Dividends paid to common stockholders	-541		-216	-162
Proceeds from the issuance of debt	546
Repayment of debt	-549		-3
Stock options exercised	5		2	1
Other, net	25		9	3
Net cash flows provided (used) by financing activities	-514		-208	-158
Net change in cash			1
Cash, beginning of year	1
Cash, end of year	$1		$1
[1]	Net income in the first quarter of 2014 includes the impairment loss on the sale of CAC.

Schedule_II_Condensed_Financia4

Schedule II. Condensed Financial Information of Registrant (Parent Company) (Schedule II. Condensed Financial Information of Registrant (Narrative)) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Guarantor Obligations, Maximum Exposure, Undiscounted	$1,900
Guarantor Obligations, Current Carrying Value	5	7
Parent Company [Member]
Guarantor Obligations, Maximum Exposure, Undiscounted	1,900
Guarantor Obligations, Current Carrying Value	5	0
Indemnification Agreement [Member] | Parent Company [Member]
Guarantor Obligations, Maximum Exposure, Undiscounted	$625

Schedule_V_Valuation_and_Quali2

Schedule V. Valuation and Qualifying Accounts (Schedule of valuation and qualifying accounts) (Details) (Allowance for doubtful accounts, insurance and reinsurance receivables [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Allowance for doubtful accounts, insurance and reinsurance receivables [Member]
Movement in valuation allowances and reserves [Roll Forward]
Balance at beginning of period	$155		$174		$203
Charged to costs and expenses	-40		-6		-23
Charged to other accounts	-1	[1]	-3	[1]	5	[1]
Deductions	-5		-10		-11
Balance at end of period	$109		$155		$174
[1]	Amount includes effects of foreign currency translation.

Schedule_VI_Supplemental_Infor2

Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Incurred claim and claim adjustment expenses related to current year	$5,043	$5,114	$5,273
Incurred claim and claim adjustment expenses related to prior years	-36	-115	-182
Consolidated Property and Casualty Insurance Entity [Member]
Deferred acquisition costs	600	624
Reserves for unpaid claim and claim adjustment expenses	23,271	24,015
Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.5% to 8.0%)	1,578	1,586
Unearned Premiums	3,592	3,718
Net written premiums	7,088	7,348	6,964
Net earned premiums	7,212	7,271	6,881
Net investment income	2,031	2,240	2,074
Incurred claim and claim adjustment expenses related to current year	5,043	5,113	5,266
Incurred claim and claim adjustment expenses related to prior years	-39	-115	-180
Amortization of deferred acquisition costs	1,317	1,362	1,274
Paid claim and claim adjustment expenses	$5,297	$5,566	$5,257
Supplemental Information Parenthetical
Minimum interest rate in discount range	3.50%
Maximum interest rate in discount range	8.00%