CNA Financial (CNA) 10-K 19 Feb 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document (USD $)	12 Months Ended
	Dec. 31, 2013
Document and Entity Information [Abstract]	'
Entity Registrant Name	'CNA FINANCIAL CORP
Entity Central Index Key	'0000021175
Current Fiscal Year End Date	'--12-31
Entity Filer Category	'Large Accelerated Filer
Document Type	'10-K
Document Period End Date	31-Dec-13
Document Fiscal Year Focus	'2013
Document Fiscal Period Focus	'FY
Amendment Flag	'false
Entity Common Stock, Shares Outstanding	269,824,832
Entity Well-known Seasoned Issuer	'Yes
Entity Voluntary Filers	'No
Entity Current Reporting Status	'Yes
Entity Public Float	$870

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues	'	'	'
Net earned premiums	$7,271	$6,882	$6,603
Net investment income	2,450	2,282	2,054
Net realized investment gains (losses):	'	'	'
Other-than-temporary impairment losses	-76	-129	-175
Portion of other-than-temporary impairments recognized in Other comprehensive income (loss)	-2	-25	-41
Net other-than-temporary impairment losses recognized in earnings	-78	-154	-216
Other net realized investment gains (loss)	109	217	214
Net realized investment gains (losses)	31	63	-2
Other revenues	361	320	294
Total revenues	10,113	9,547	8,949
Claims, Benefits and Expenses	'	'	'
Insurance claims and policyholders’ benefits	5,947	5,896	5,489
Amortization of deferred acquisition costs	1,362	1,274	1,176
Other operating expenses	1,325	1,335	1,238
Interest	166	170	175
Total claims, benefits and expenses	8,800	8,675	8,078
Income (loss) from continuing operations before income tax	1,313	872	871
Income tax (expense) benefit	-376	-244	-242
Income (loss) from continuing operations	937	628	629
Income (loss) from discontinued operations, net of income tax (expense) benefit of -,- and $0	'	'	-1
Net income (loss)	937	628	628
Net (income) loss attributable to noncontrolling interests	'	'	-16
Net income (loss) attributable to CNA	$937	$628	$612
Basic Earnings (Loss) Per Share Attributable to CNA	'	'	'
Income (loss) from continuing operations attributable to CNA	$3.48	$2.33	$2.27
Income (loss) from discontinued operations attributable to CNA	'	'	'
Basic earnings (loss) per share attributable to CNA common stockholders	$3.48	$2.33	$2.27
Diluted Earnings (Loss) Per Share Attributable to CNA	'	'	'
Income (loss) from continuing operations attributable to CNA	$3.47	$2.33	$2.27
Income (loss) from discontinued operations attributable to CNA	'	'	'
Diluted earnings (loss) per share attributable to CNA common stockholders	$3.47	$2.33	$2.27
Dividends per share	$0.80	$0.60	$0.40
Weighted Average Outstanding Common Stock and Common Stock Equivalents	'	'	'
Basic	269.7	269.4	269.3
Diluted	270.2	269.8	269.6

Consolidated_Statements_of_Ope1

Consolidated Statements of Operations Parenthetical (Parentheticals) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statements of Operations [Abstract]	'	'	'
Income tax (expense) benefit on discontinued operations	'	'	'

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Other Comprehensive Income, Net of Tax, Changes In:	'	'	'
Net unrealized gains (losses) on investments with other-than-temporary impairments	$6	$84	$10
Net unrealized gains (losses) on other investments	-679	339	365
Net unrealized gains (losses) on investments	-673	423	375
Net unrealized gains (losses) on discontinued operations and other	'	'	-1
Foreign currency translation adjustment	-11	40	-15
Pension and postretirement benefits	295	-112	-208
Other comprehensive income (loss), net of tax	-389	351	151
Net income (loss)	937	628	628
Comprehensive income (loss)	548	979	779
Net unrealized (gains) losses on investments attributable to noncontrolling interests	'	'	-8
Other comprehensive (income) loss attributable to noncontrolling interests	'	'	-8
Net (income) loss attributable to noncontrolling interests	'	'	-16
Comprehensive (income) loss attributable to noncontrolling interests	'	'	-24
Total comprehensive income (loss) attributable to CNA	$548	$979	$755

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Assets	'	'
Fixed maturity securities at fair value (amortized cost of $39,311 and $38,170)	$41,233	$42,633
Equity securities at fair value (cost of $179 and $228)	185	249
Limited partnership investments	2,720	2,462
Other invested assets	54	59
Mortgage loans	508	401
Short term investments	1,407	1,832
Total investments	46,107	47,636
Cash	195	156
Reinsurance receivables (less allowance for uncollectible receivables of $71 and $73)	6,017	6,158
Insurance receivables (less allowance for uncollectible receivables of $84 and $101)	1,979	1,882
Accrued investment income	443	434
Deferred acquisition costs	624	598
Deferred income taxes	220	93
Property and equipment at cost (less accumulated depreciation of $365 and $404)	304	326
Goodwill	155	154
Other assets (includes $0 and $4 due from Loews Corporation)	969	773
Separate account business	181	312
Total assets	57,194	58,522
Liabilities	'	'
Claim and claim adjustment expenses	24,089	24,763
Unearned premiums	3,718	3,610
Future policy benefits	10,471	11,475
Policyholders’ funds	116	157
Short term debt	549	13
Long term debt	2,011	2,557
Other liabilities (includes $178 and $0 due to Loews Corporation)	3,408	3,321
Separate account business	181	312
Total liabilities	44,543	46,208
Commitments and contingencies (Notes B, G and L)	'	'
Stockholders' Equity	'	'
Common stock ($2.50 par value; 500,000,000 shares authorized; 273,040,243 shares issued; 269,717,583 and 269,399,390 shares outstanding)	683	683
Additional paid-in capital	2,145	2,146
Retained earnings	9,495	8,774
Accumulated other comprehensive income (loss)	442	831
Treasury stock (3,322,660 and 3,640,853 shares), at cost	-91	-99
Notes receivable for the issuance of common stock	-23	-21
Total stockholders’ equity	12,651	12,314
Total liabilities and stockholders' equity	$57,194	$58,522

Consolidated_Balance_Sheet_Par

Consolidated Balance Sheet Parentheticals (Parentheticals) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Fixed maturities securities at amortized cost	$39,311	$38,170
Equity securities at cost	179	228
Allowance for uncollectible reinsurance receivables	71	73
Allowance for uncollectible insurance receivables	84	101
Accumulated depreciation on property and equipment	365	404
Other assets receivable from Loews Corporation	'	4
Other liabilities payable to Loews Corporation	$178	'
Common stock, par value	$2.50	$2.50
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	273,040,243	273,040,243
Common stock, shares outstanding	269,717,583	269,399,390
Treasury stock, shares	3,322,660	3,640,853

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flows from Operating Activities	'	'	'
Net income (loss)	$937	$628	$628
Adjustments to reconcile net income (loss) to net cash flows provided (used) by operating activities:	'	'	'
(Income) loss from discontinued operations	'	'	1
(Gain) loss on disposal of property and equipment	'	4	9
Deferred income tax expense (benefit)	77	147	188
Trading portfolio activity	-10	-23	1
Net realized investment (gains) losses	-31	-63	2
Equity method investees	-323	-89	97
Amortization of investments	-24	-55	-64
Depreciation and amortization	101	125	79
Changes in:	'	'	'
Receivables, net	44	49	1,020
Accrued investment income	-9	4	-17
Deferred acquisition costs	2	-16	-1
Insurance reserves	-68	430	-237
Other assets	-27	144	175
Other liabilities	525	-49	-187
Other, net	10	14	10
Total adjustments	267	622	1,076
Net cash flows provided (used) by operating activities-continuing operations	1,204	1,250	1,704
Net cash flows provided (used) by operating activities-discontinued operations	'	'	-2
Net cash flows provided (used) by operating activities-total	1,204	1,250	1,702
Dispositions:	'	'	'
Fixed maturity securities - sales	6,869	6,123	7,579
Fixed maturity securities - maturities, calls and redemptions	3,271	3,699	3,055
Equity securities	103	86	178
Limited partnerships	108	165	57
Mortgage loans	22	7	2
Purchases:	'	'	'
Fixed maturity securities	-11,197	-10,299	-12,168
Equity securities	-77	-54	-72
Limited partnerships	-223	-228	-215
Mortgage loans	-129	-174	-149
Change in other investments	-22	22	17
Change in short term investments	425	-7	566
Purchase of Hardy	'	-197	'
Purchases of property and equipment	-91	-94	-84
Other dispositions	32	1	171
Other, net	11	16	1
Net cash flows provided (used) by investing activities-continuing operations	-898	-934	-1,062
Net cash flows provided (used) by investing activities-discontinued operations	'	'	2
Net cash flows provided (used) by investing activities-total	-898	-934	-1,060
Cash Flows from Financing Activities	'	'	'
Acquisition of CNA Surety noncontrolling interest	'	'	-475
Dividends paid to common stockholders	-216	-162	-108
Proceeds from the issuance of debt	'	'	396
Repayment of debt	-13	-70	-451
Stock options exercised	2	1	2
Other, net	-37	-8	-8
Net cash flows provided (used) by financing activities-continuing operations	-264	-239	-644
Net cash flows provided (used) by financing activities-discontinued operations	'	'	'
Net cash flows provided (used) by financing activities-total	-264	-239	-644
Effect of foreign exchange rate changes on cash	-3	4	'
Net change in cash	39	81	-2
Cash, beginning of year	156	75	77
Cash, end of year	$195	$156	$75

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]	Parent [Member]	Noncontrolling interest [Member]
In Millions, unless otherwise specified
Balance at Dec. 31, 2010	'	$683	$2,200	$7,804	$326	($105)	($26)	'	$563
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'	'
Net income (loss)	628	'	'	612	'	'	'	'	16
Other comprehensive income (loss)	151	'	'	'	143	'	'	'	8
Dividends paid to common stockholders	'	'	'	-108	'	'	'	'	'
Stock-based compensation	'	'	4	'	'	3	'	'	'
(Increase) Decrease in notes receivable from the issuance of common stock	'	'	'	'	'	'	4	'	'
Other	'	'	2	'	'	'	'	'	-11
Acquisition of CNA Surety noncontrolling interest	'	'	-65	'	19	'	'	'	-429
Disposition of FICOH ownership interest	'	'	'	'	-8	'	'	'	-147
Balance at Dec. 31, 2011	11,488	683	2,141	8,308	480	-102	-22	11,488	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'	'
Net income (loss)	628	'	'	628	'	'	'	'	'
Other comprehensive income (loss)	351	'	'	'	351	'	'	'	'
Dividends paid to common stockholders	'	'	'	-162	'	'	'	'	'
Stock-based compensation	'	'	5	'	'	3	'	'	'
(Increase) Decrease in notes receivable from the issuance of common stock	'	'	'	'	'	'	1	'	'
Other	'	'	'	'	'	'	'	'	'
Acquisition of CNA Surety noncontrolling interest	'	'	'	'	'	'	'	'	'
Disposition of FICOH ownership interest	'	'	'	'	'	'	'	'	'
Balance at Dec. 31, 2012	12,314	683	2,146	8,774	831	-99	-21	12,314	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'	'
Net income (loss)	937	'	'	937	'	'	'	'	'
Other comprehensive income (loss)	-389	'	'	'	-389	'	'	'	'
Dividends paid to common stockholders	'	'	'	-216	'	'	'	'	'
Stock-based compensation	'	'	-1	'	'	8	'	'	'
(Increase) Decrease in notes receivable from the issuance of common stock	'	'	'	'	'	'	-2	'	'
Other	'	'	'	'	'	'	'	'	'
Acquisition of CNA Surety noncontrolling interest	'	'	'	'	'	'	'	'	'
Disposition of FICOH ownership interest	'	'	'	'	'	'	'	'	'
Balance at Dec. 31, 2013	$12,651	$683	$2,145	$9,495	$442	($91)	($23)	$12,651	'

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
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, 2013.
	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.
	The Company has historically reported certain run-off insurance operations acquired in its merger with The Continental Corporation in 1995 as discontinued operations. Due to the immateriality of the remaining liabilities, effective in the third quarter of 2011, the Company is no longer reporting these run-off operations as discontinued operations.
	Business
	The Company's core property and casualty insurance operations are reported in three business segments: CNA Specialty, CNA Commercial and Hardy. The Company's non-core operations are managed in two segments: Life & Group Non-Core and Corporate & Other Non-Core.
	The Company serves a wide variety of customers, including small, medium and large businesses; insurance companies; associations; professionals; groups; and individuals with a broad range of insurance and risk management products and services.
	Core insurance products include commercial property and casualty coverages, including surety. Non-core insurance products, which primarily have been placed in run-off, include life, long term care and retirement products and annuities. 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.
	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 Lloyd's 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 July 2, 2012 are included in the results of our core property and casualty insurance operations as a separate 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 and Other Non-Core segment.
	Noncontrolling Interests
	Net income attributable to noncontrolling interests for the year ended December 31, 2011 represented the noncontrolling interests in CNA Surety Corporation (Surety) and First Insurance Company of Hawaii (FICOH). On June 10, 2011, CNA completed the acquisition of the noncontrolling interest of Surety and on November 29, 2011, CNA completed the sale of its 50% ownership interest in FICOH.
	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 $1.3 billion as of December 31, 2013 and 2012. 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. Certain structured settlements are funded by annuities purchased from Continental Assurance Company (CAC) for which the related annuity obligations are reported in Future policy benefits reserves. 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 7.1% to 9.7% at December 31, 2013 and 2012. At December 31, 2013 and 2012, the discounted reserves for unfunded structured settlements were $580 million and $602 million, net of discount of $969 million and $1.0 billion.
	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 3.0% to 6.8% at December 31, 2013 and 3.0% to 6.5% at December 31, 2012. At December 31, 2013 and 2012, such discounted reserves totaled $2.4 billion and $2.2 billion, net of discount of $617 million and $837 million.
	Future policy benefits reserves: Reserves for long term care products and payout annuity contracts are computed using the net level premium method, which incorporates actuarial assumptions as to morbidity, mortality, persistency, discount rate and expenses. Expense assumptions include the estimated effects of expenses to be incurred beyond the premium paying period. 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, 2013 and from 5.0% to 7.4% at December 31, 2012. Interest rates for payout annuity contracts range from 5.0% to 8.7% at December 31, 2013 and 2012. In 2012, the Company unlocked assumptions related to its payout annuity contracts due to anticipated adverse changes in discount rates, which reflected the then current low interest rate environment and our view of expected investment yields, resulting in loss recognition which increased insurance liabilities by $33 million.
	Policyholders' funds reserves: Policyholders' funds reserves primarily include 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, 2013 and 2012, the liability balances were $143 million. As of December 31, 2013 and 2012, included in Other assets on the Consolidated Balance Sheets were $1 million and $2 million of related assets for premium tax offsets. This asset is limited to the amount that is able to be offset against premium tax on future premium collections from business written or committed to be written.
	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, 2013 and 2012, and $130 million and $125 million recorded as deposit liabilities at December 31, 2013 and 2012. 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.
	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, 2013 and 2012, Deferred acquisition costs were presented net of Shadow Adjustments, as defined later in this note, of $342 million and $369 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 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 $88 million and $100 million at December 31, 2013 and 2012, 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.
	December 31, 2013	Number of Life Settlement Contracts	Fair Value of Life Settlement Contracts		Face Amount of Life Insurance Policies
			(In millions)		(In millions)
	Estimated maturity during:
	2014	60	$	13	$	39
	2015	60	11		35
	2016	50	9		32
	2017	50	8		29
	2018	40	7		26
	Thereafter	364	40		217
	Total	624	$	88	$	378
	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, 2013, 2012 and 2011 on contracts still being held was $(2) million, $11 million and $5 million. The gains recognized during the years ended December 31, 2013, 2012 and 2011 on contracts that settled were $15 million, $42 million and $28 million.
	Separate Account Business: Separate account assets and liabilities represent contract holder funds related to investment and annuity products for which the policyholder assumes substantially all the risk and reward. The assets are segregated into accounts with specific underlying investment objectives and are legally segregated from the Company. All assets of the separate account business are carried at fair value with an equal amount recorded for separate account liabilities. Fee income accruing to the Company related to separate accounts is primarily included within Other revenues on the Consolidated Statements of Operations.
	A number of separate account pension deposit contracts guarantee principal and an annual minimum rate of interest. If aggregate contract value in the separate account exceeds the fair value of the related assets, an additional Policyholders' funds liability is established. Certain of these contracts are subject to a fair value adjustment if terminated by the policyholder.
	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, decreased $979 million and increased $789 million for the years ended December 31, 2013 and 2012. At December 31, 2013 and 2012, net unrealized gains on investments included in Accumulated other comprehensive income (AOCI) were correspondingly reduced by $532 million and $1,511 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 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 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. For asset-backed securities, 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.
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 Accumulated other comprehensive income. 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 of $2 million, $12 million and $4 million were included in determining net income (loss) for the years ended December 31, 2013, 2012 and 2011.
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 related to Hardy 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, 2013, 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.
Intangible Assets
Intangible assets are reported within Other assets. Finite-lived intangible assets are amortized over their estimated useful lives. Indefinite-lived intangible assets are tested for impairment annually or when certain triggering events require such tests.
Earnings (Loss) Per Share Data
Earnings (loss) per share attributable to the Company's common stockholders 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) attributable to CNA 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, 2013, 2012 and 2011, approximately 552 thousand, 417 thousand and 290 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 111 thousand, 730 thousand and 1.1 million 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 $164 million, $170 million and $175 million for the years ended December 31, 2013, 2012 and 2011. Cash payments made for income taxes were $129 million and $61 million for the years ended December 31, 2013 and 2011. Cash refunds received for income taxes were $29 million for the year ended December 31, 2012.

Investments

Investments	12 Months Ended
	Dec. 31, 2013
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)	2013			2012			2011
	Fixed maturity securities	$	1,998		$	2,022		$	2,011
	Short term investments	3			5			8
	Limited partnership investments	451			251			48
	Equity securities	12			12			20
	Mortgage loans	23			17			9
	Trading portfolio	17			24			9
	Other	2			7			7
	Gross investment income	2,506			2,338			2,112
	Investment expense	(56		)	(56		)	(58		)
	Net investment income	$	2,450		$	2,282		$	2,054
	As of December 31, 2013, the Company held no non-income producing fixed maturity securities. As of December 31, 2012, the Company held nine non-income producing fixed maturity securities aggregating $1 million of fair value. As of December 31, 2013 and 2012, 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)	2013			2012			2011
	Net realized investment gains (losses):
	Fixed maturity securities:
	Gross realized gains	$	201		$	232		$	289
	Gross realized losses	(146		)	(149		)	(311		)
	Net realized investment gains (losses) on fixed maturity securities	55			83			(22		)
	Equity securities:
	Gross realized gains	13			19			10
	Gross realized losses	(35		)	(42		)	(11		)
	Net realized investment gains (losses) on equity securities	(22		)	(23		)	(1		)
	Derivatives	(9		)	(2		)	—
	Short term investments and other	7			5			21
	Net realized investment gains (losses)	$	31		$	63		$	(2	)
	Net change in unrealized gains on investments is presented in the following table.
	Net Change in Unrealized Gains
	Years ended December 31
	(In millions)	2013			2012			2011
	Net change in unrealized gains on investments:
	Fixed maturity securities	$	(2,541	)	$	1,871		$	1,442
	Equity securities	(15		)	5			(2		)
	Other	—			(1		)	(3		)
	Total net change in unrealized gains on investments	$	(2,556	)	$	1,875		$	1,437
	The components of OTTI losses recognized in earnings by asset type are summarized in the following table.
	Years ended December 31
	(In millions)	2013			2012			2011
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	22		$	27		$	95
	States, municipalities and political subdivisions	—			34			—
	Asset-backed:
	Residential mortgage-backed	19			50			105
	Other asset-backed	2			—			6
	Total asset-backed	21			50			111
	U.S. Treasury and obligations of government-sponsored enterprises	—			1			—
	Total fixed maturity securities available-for-sale	43			112			206
	Equity securities available-for-sale:
	Common stock	8			6			8
	Preferred stock	26			36			1
	Total equity securities available-for-sale	34			42			9
	Short term investments	1			—			1
	OTTI losses recognized in earnings	$	78		$	154		$	216
	The following tables provide a summary of fixed maturity and equity securities.
	Summary of Fixed Maturity and Equity Securities
	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
December 31, 2012	Cost or			Gross			Gross			Estimated		Unrealized
	Amortized			Unrealized			Unrealized			Fair		OTTI
(In millions)	Cost			Gains			Losses			Value		Losses (Gains)
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	19,530		$	2,698		$	21		$	22,207	$	—
States, municipalities and political subdivisions	9,372			1,455			44			10,783		—
Asset-backed:
Residential mortgage-backed	5,745			246			71			5,920		(28		)
Commercial mortgage-backed	1,692			147			17			1,822		(3		)
Other asset-backed	929			23			—			952		—
Total asset-backed	8,366			416			88			8,694		(31		)
U.S. Treasury and obligations of government-sponsored enterprises	172			11			1			182		—
Foreign government	588			25			—			613		—
Redeemable preferred stock	113			13			1			125		—
Total fixed maturity securities available-for-sale	38,141			4,618			155			42,604		$	(31	)
Total fixed maturity securities trading	29			—			—			29
Equity securities available-for-sale:
Common stock	38			14			—			52
Preferred stock	190			7			—			197
Total equity securities available-for-sale	228			21			—			249
Total	$	38,398		$	4,639		$	155		$	42,882
The 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, 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
	Less than 12 Months						12 Months or Longer					Total
December 31, 2012	Estimated			Gross			Estimated			Gross		Estimated			Gross
	Fair Value			Unrealized			Fair Value			Unrealized		Fair Value			Unrealized
(In millions)				Losses						Losses					Losses
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	846		$	13		$	108		$	8	$	954		$	21
States, municipalities and political subdivisions	254			5			165			39		419			44
Asset-backed:
Residential mortgage-backed	583			5			452			66		1,035			71
Commercial mortgage-backed	85			2			141			15		226			17
Total asset-backed	668			7			593			81		1,261			88
U.S. Treasury and obligations of government-sponsored enterprises	23			1			—			—		23			1
Redeemable preferred stock	28			1			—			—		28			1
Total	$	1,819		$	27		$	866		$	128	$	2,685		$	155
Based on current facts and circumstances, the Company believes the unrealized losses presented in the December 31, 2013 Securities in a Gross Unrealized Loss Position table above, are primarily attributable to broader economic conditions, changes in interest rates and credit spreads, market illiquidity and other market factors, but are not indicative of the ultimate collectibility of the current amortized cost of the securities. The investments with longer duration, primarily included within the states, municipalities and political subdivision asset category, were more significantly impacted by changes in market interest rates. The Company has no current intent to sell these securities, nor is it more likely than not that it will be required to sell prior to recovery of amortized cost; accordingly, the Company has determined that there are no additional OTTI losses to be recorded at December 31, 2013.
The following table summarizes the activity for the years ended December 31, 2013, 2012 and 2011 related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held at December 31, 2013, 2012 and 2011 for which a portion of an OTTI loss was recognized in Other comprehensive income.
Years ended December 31
(In millions)	2013			2012			2011
Beginning balance of credit losses on fixed maturity securities	$	95		$	92		$	141
Additional credit losses for securities for which an OTTI loss was previously recognized	2			23			39
Credit losses for securities for which an OTTI loss was not previously recognized	—			2			11
Reductions for securities sold during the period	(23		)	(14		)	(67		)
Reductions for securities the Company intends to sell or more likely than not will be required to sell	—			(8		)	(32		)
Ending balance of credit losses on fixed maturity securities	$	74		$	95		$	92
Contractual Maturity
The following table summarizes available-for-sale fixed maturity securities by contractual maturity at December 31, 2013 and 2012. Actual maturities may differ from contractual maturities because certain securities may be called or prepaid with or without call or prepayment penalties. Securities not due at a single date are allocated based on weighted average life.
Contractual Maturity
	December 31, 2013						December 31, 2012
(In millions)	Cost or			Estimated			Cost or			Estimated
	Amortized			Fair			Amortized			Fair
	Cost			Value			Cost			Value
Due in one year or less	$	2,420		$	2,455		$	1,648		$	1,665
Due after one year through five years	9,496			10,068			13,603			14,442
Due after five years through ten years	11,667			11,954			8,726			9,555
Due after ten years	15,692			16,720			14,164			16,942
Total	$	39,275		$	41,197		$	38,141		$	42,604
Limited Partnerships
The carrying value of limited partnerships as of December 31, 2013 and 2012 was $2,720 million and $2,462 million, which includes undistributed earnings of $969 million and $768 million. Limited partnerships comprising 67% of the total carrying value are reported on a current basis through December 31, 2013 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, 2013 and 2012, the Company had 87 and 79 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, 74% and 80% at December 31, 2013 and 2012 employ hedge fund strategies that generate returns through investing in securities that are marketable while engaging in various management techniques primarily in public fixed income and equity markets. These hedge fund strategies include both long and short positions in fixed income, equity and derivative instruments. The 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 51% were equity related, 28% pursued a multi-strategy approach, 17% were focused on distressed investments and 4% were fixed income related at December 31, 2013.
Limited partnerships representing 22% and 16% at December 31, 2013 and 2012 were invested in private debt and equity. The remaining were invested in various other partnerships including real estate. The ten largest limited partnership positions held totaled $1,471 million and $1,309 million as of December 31, 2013 and 2012. 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, 2013 and 2012, and the related income reflected on the Consolidated Statements of Operations represents approximately 4%, 3%, and 4% of the changes in total partnership equity for the years ended December 31, 2013, 2012 and 2011.
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, 2013 and 2012, there were no loans past due or in non-accrual status, and no valuation allowance was recorded.
Investment Commitments
As of December 31, 2013, the Company had committed approximately $381 million to future capital calls from various third-party limited partnership investments in exchange for an ownership interest in the related partnerships.
The Company invests in various privately placed debt securities, including bank loans, as part of its overall investment strategy and has committed to additional future purchases, sales and funding. As of December 31, 2013, the Company had commitments to purchase or fund additional amounts of $151 million and sell $145 million under the terms of such securities.
Investments on Deposit
Securities with carrying values of approximately $3.3 billion and $3.6 billion were deposited by the Company’s insurance subsidiaries under requirements of regulatory authorities and others as of December 31, 2013 and 2012.
Cash and securities with carrying values of approximately $353 million and $4 million were deposited with financial institutions as collateral for letters of credit as of December 31, 2013 and 2012. 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 $294 million and $277 million as of December 31, 2013 and 2012.

Derivative_Financial_Instrumen

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2013
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. Credit derivatives such as credit default swaps (CDS) are entered into to modify the credit risk inherent in certain investments. 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, 2013 and 2012. There was no cash collateral provided by the Company at December 31, 2013. The fair value of cash collateral provided by the Company was $1 million at December 31, 2012. There was no cash collateral received from counterparties held at December 31, 2013 or 2012.
	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, 2013	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Equity warrants	$	5	$	—	$	—
	December 31, 2012	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Credit default swaps - purchased protection	$	20	$	—	$	(1	)
	Currency forwards	59		—		(2		)
	Equity warrants	5		—		—
	Total	$	84	$	—	$	(3	)
	During the year ended December 31, 2013, new derivative transactions entered into totaled $2,743 million in notional value while derivative termination activity totaled $2,822 million. This activity was primarily attributable to forward commitments for mortgage-backed securities, options, interest rate futures, and foreign currency forwards. During the year ended December 31, 2012, new derivative transactions entered into totaled $1,581 million in notional value while derivative termination activity totaled $1,543 million. This activity was primarily attributable to interest rate futures, forward commitments for mortgage-backed securities and foreign currency forwards.

Fair_Value

Fair Value	12 Months Ended
	Dec. 31, 2013
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, 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
	Liabilities
	Derivative financial instruments, included in Other liabilities	$	—	$	—		$	—		$	—
	Total liabilities	$	—	$	—		$	—		$	—
	December 31, 2012									Total
										Assets/(Liabilities)
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	6	$	22,011		$	219		$	22,236
	States, municipalities and political subdivisions	—		10,687			96			10,783
	Asset-backed:
	Residential mortgage-backed	—		5,507			413			5,920
	Commercial mortgage-backed	—		1,693			129			1,822
	Other asset-backed	—		584			368			952
	Total asset-backed	—		7,784			910			8,694
	U.S. Treasury and obligations of government-sponsored enterprises	158		24			—			182
	Foreign government	140		473			—			613
	Redeemable preferred stock	40		59			26			125
	Total fixed maturity securities	344		41,038			1,251			42,633
	Equity securities	117		98			34			249
	Other invested assets	—		58			1			59
	Short term investments	987		799			6			1,792
	Life settlement contracts, included in Other assets	—		—			100			100
	Separate account business	4		306			2			312
	Total assets	$	1,452	$	42,299		$	1,394		$	45,145
	Liabilities
	Derivative financial instruments, included in Other liabilities	$	—	$	(2	)	$	(1	)	$	(3	)
	Total liabilities	$	—	$	(2	)	$	(1	)	$	(3	)
	The tables below present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the years ended December 31, 2013 and 2012.
	Level 3	Balance at		Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at		Unrealized gains (losses) on Level 3 assets and liabilities held at 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	)
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, 2012 recognized in net income (loss)*
(In millions)	January 1,																	Level 3		of Level 3			December 31,
	2012																						2012
Fixed maturity securities:
Corporate and other bonds	$	482	$	6		$	4		$	231		$	(136	)	$	(88	)	$	45	$	(325	)	$	219	$	(3	)
States, municipalities and political subdivisions	171		—			—			14			—			(89		)	—		—			96		—
Asset-backed:
Residential mortgage-backed	452		(14		)	2			97			—			(40		)	—		(84		)	413		(18		)
Commercial mortgage-backed	59		8			14			165			(12		)	(28		)	13		(90		)	129		—
Other asset-backed	343		11			8			615			(365		)	(128		)	—		(116		)	368		—
Total asset-backed	854		5			24			877			(377		)	(196		)	13		(290		)	910		(18		)
Redeemable preferred stock	—		—			(1		)	53			(26		)	—			—		—			26		—
Total fixed maturity securities	1,507		11			27			1,175			(539		)	(373		)	58		(615		)	1,251		(21		)
Equity securities	67		(36		)	6			27			(16		)	—			—		(14		)	34		(38		)
Other invested assets, including derivatives, net	10		—			—			—			—			(10		)	—		—			—		—
Short term investments	27		—			—			23			(4		)	(41		)	1		—			6		—
Life settlement contracts	117		53			—			—			—			(70		)	—		—			100		11
Separate account business	23		—			—			—			(21		)	—			—		—			2		—
Total	$	1,751	$	28		$	33		$	1,225		$	(580	)	$	(494	)	$	59	$	(629	)	$	1,393	$	(48	)
* 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
Securities shown in the Level 3 tables on the previous pages may be transferred in or out of Level 3 based on the availability of observable market information used to determine the fair value of the security. The availability of observable market information varies based on market conditions and trading volume and may cause securities to move in and out of Level 3 from reporting period to reporting period. There were no transfers between Level 1 and Level 2 during the year ended December 31, 2013. There were $106 million of transfers from Level 2 to Level 1 and $72 million of transfers from Level 1 to Level 2 during the year ended December 31, 2012. The Company's policy is to recognize transfers between levels at the beginning of quarterly reporting periods.
Valuation Methodologies and Inputs
The following section describes the valuation methodologies and relevant inputs used to measure different financial instruments at fair value, including an indication of the level in the fair value hierarchy in which the instruments are generally classified.
Fixed Maturity Securities
Fixed maturity securities are valued using methodologies that model information generated by market transactions involving identical or comparable assets, as well as discounted cash flow methodologies. Common inputs include: prices from recently executed transactions of similar securities, broker/dealer quotes, benchmark yields, spreads off benchmark yields, interest rates, and U.S. Treasury or swap curves. Specifically for asset-backed securities, key inputs include prepayment and default projections based on past performance of the underlying collateral and current market data.
Level 1 securities include exchange traded bonds, highly liquid U.S. and foreign government bonds, and redeemable preferred stock, valued using quoted market prices. Level 2 securities include most other fixed maturity securities as the significant inputs are observable in the marketplace. Securities are generally assigned to Level 3 in cases where broker/dealer quotes are significant inputs to the valuation and there is a lack of transparency as to whether these quotes are based on information that is observable in the marketplace. Level 3 securities also include tax-exempt auction rate certificates and private placement debt securities. Fair value of auction rate securities is determined utilizing a pricing model with three primary inputs. The interest rate and spread inputs are observable from like instruments while the expected call date assumption is unobservable due to the uncertain nature of principal prepayments prior to maturity and the credit spread adjustment that is security specific. Fair value of certain private placement debt securities is determined using internal models with inputs that are not market observable.
Equity Securities
Level 1 equity securities include publicly traded securities valued using quoted market prices. Level 2 securities are primarily non-redeemable preferred stocks and common stocks valued using pricing for similar securities, recently executed transactions, broker/dealer quotes and other pricing models utilizing market observable inputs. Level 3 securities are priced using internal models with inputs that are not market observable.
Other Invested Assets
Level 1 securities include exchange traded derivatives, primarily futures, valued using quoted market prices. Level 2 securities include overseas deposits, which can be redeemed at net asset value in 90 days or less, and derivatives, primarily currency forwards valued using observable market forward rates. Over-the-counter derivatives, principally interest rate swaps, total return swaps, credit default swaps, equity warrants and options, are valued using inputs including broker/dealer quotes and are classified within Level 3 of the valuation hierarchy due to a lack of transparency as to whether these quotes are based on information that is observable in the marketplace.
Short Term Investments
Securities that are actively traded or have quoted prices are classified as Level 1. These securities include money market funds and treasury bills. Level 2 primarily includes commercial paper, for which all inputs are market observable. Fixed maturity securities purchased within one year of maturity are classified consistent with fixed maturity securities discussed above. Short term investments as presented in the tables above differ from the amounts presented on the Consolidated Balance Sheets because certain short term investments, such as time deposits, are not measured at fair value.
Life Settlement Contracts
The fair values of life settlement contracts are determined as the present value of the anticipated death benefits less anticipated premium payments based on contract terms that are distinct for each insured, as well as the Company's own assumptions for mortality, premium expense, and the rate of return that a buyer would require on the contracts, as no comparable market pricing data is available.
Separate Account Business
Separate account business includes fixed maturity securities, equities and short term investments. The valuation methodologies and inputs for these asset types have been described above.
Significant Unobservable Inputs
The table below presents quantitative information about the significant unobservable inputs utilized by the Company in the fair value measurements of Level 3 assets. Valuations for assets and liabilities not presented in the table below are primarily based on broker/dealer quotes for which there is a lack of transparency as to inputs used to develop the valuations. The quantitative detail of these unobservable inputs is neither provided nor reasonably available to the Company.
Assets	Fair Value at December 31, 2013		Valuation Technique(s)		Unobservable Input(s)	Range
(In millions)						(Weighted Average)
Fixed maturity securities	$	142	Discounted cash flow		Credit spread	1.74% - 19.90% (3.98%)
Equity securities	$	10	Market approach		Private offering price	$360.12 - $4,267.66 per share ($1,147.95)
Life settlement contracts	$	88	Discounted cash flow		Discount rate risk premium	9%
					Mortality assumption	70% - 743% (191.6%)
Assets	Fair Value at December 31, 2012		Valuation Technique(s)		Unobservable Input(s)	Range
(In millions)						(Weighted Average)
Fixed maturity securities	$	121	Discounted cash flow		Expected call date	3.3 - 5.3 years (4.3 years)
					Credit spread adjustment	0.02% - 0.48% (0.17%)
	$	72	Market approach		Private offering price	$42.39 - $102.32 ($100.11)
Equity securities	$	34	Market approach		Private offering price	$4.54 - $3,842.00 per share
						($571.17 per share)
Life settlement contracts	$	100	Discounted cash flow		Discount rate risk premium	9%
					Mortality assumption	69% - 883% (208.9%)
For fixed maturity securities, an increase to the expected call date and credit spread assumptions would result in a lower fair value measurement. For equity securities, an increase in the private offering price would result in a higher fair value measurement. For life settlement contracts, an increase in the discount rate risk premium or decrease in the mortality assumption would result in a lower fair value measurement.
Financial Assets and Liabilities Not Measured at Fair Value
The carrying amount and estimated fair value of the Company's financial instrument assets and liabilities which are not measured at fair value on the Consolidated Balance Sheets are listed in the tables below.
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
31-Dec-12	Carrying		Estimated Fair Value
(In millions)	Amount		Level 1			Level 2			Level 3			Total
Financial assets
Notes receivable for the issuance of common stock	$	21	$	—		$	—		$	21		$	21
Mortgage loans	401		—			—			418			418
Financial liabilities
Premium deposits and annuity contracts	$	100	$	—		$	—		$	104		$	104
Short term debt	13		—			13			—			13
Long term debt	2,557		—			3,016			—			3,016
The following methods and assumptions were used to estimate the fair value of these financial assets and liabilities.
The fair values of Notes receivable for the issuance of common stock were estimated using discounted cash flows utilizing interest rates currently offered for obligations securitized with similar collateral, adjusted for specific note receivable risk.
The fair values of Mortgage loans were based on the present value of the expected future cash flows discounted at the current interest rate for origination of similar quality loans, adjusted for specific loan risk.
Premium deposits and annuity contracts were valued based on cash surrender values or estimated fair values of policyholder liabilities, net of amounts ceded related to sold business.
The Company's senior notes and debentures were valued based on observable market prices. The fair value for other debt was estimated using discounted cash flows based on current incremental borrowing rates for similar borrowing arrangements.
The carrying amounts reported on the 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, 2013
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 year ended December 31, 2013, the Company paid $89 million to Loews related to federal income taxes. For the years ended December 31, 2012 and 2011, the Company received from Loews $75 million and $10 million related to federal income taxes.
	For 2011 through 2013, 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, 2013 and 2012, 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 2013, the Company did not recognize any interest or penalties. During 2012, the Company recognized $2 million of interest income and no penalties. During 2011, the Company did not recognize any interest or penalties. There were no amounts accrued for interest or penalties at December 31, 2013 or 2012.
	The following table provides a reconciliation 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)	2013			2012			2011
	Income tax expense at statutory rates	$	(460	)	$	(305	)	$	(305	)
	Tax benefit from tax exempt income	97			84			74
	Foreign taxes and credits	(1		)	(13		)	(3		)
	Taxes related to domestic affiliate	—			—			(21		)
	Prior year tax adjustment	—			—			20
	Other tax expense	(12		)	(10		)	(7		)
	Income tax expense	$	(376	)	$	(244	)	$	(242	)
	At December 31, 2013, 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) benefit.
	Current and Deferred Taxes
	Years ended December 31
	(In millions)	2013			2012			2011
	Current tax expense	$	(299	)	$	(97	)	$	(54	)
	Deferred tax expense	(77		)	(147		)	(188		)
	Total income tax expense	$	(376	)	$	(244	)	$	(242	)
	Total income tax presented above includes foreign tax expense of approximately $24 million, $34 million and $27 million related to income from continuing foreign operations of approximately $101 million, $88 million and $75 million for the years ended December 31, 2013, 2012 and 2011.
	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)	2013			2012
	Deferred Tax Assets:
	Insurance reserves:
	Property and casualty claim and claim adjustment expense reserves	$	289		$	352
	Unearned premium reserves	178			162
	Receivables	50			60
	Employee benefits	187			384
	Life settlement contracts	46			45
	Deferred retroactive reinsurance benefit	66			—
	Other assets	149			160
	Gross deferred tax assets	965			1,163
	Deferred Tax Liabilities:
	Investment valuation differences	68			38
	Deferred acquisition costs	232			238
	Net unrealized gains	383			737
	Other liabilities	62			57
	Gross deferred tax liabilities	745			1,070
	Net deferred tax asset	$	220		$	93
	At December 31, 2013, 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, 2013 or 2012.

Claim_and_Claim_Adjustment_Exp

Claim and Claim Adjustment Expense Reserves	12 Months Ended
	Dec. 31, 2013
Insurance Loss Reserves [Abstract]	'
Claim and Claim Adjustment Expense Reserves	'
	Note F. Claim and Claim Adjustment Expense Reserves
	The Company's property and casualty insurance claim and claim adjustment expense reserves represent the estimated amounts necessary to resolve all outstanding claims, including IBNR claims as of the reporting date. The Company's reserve projections are based primarily on detailed analysis of the facts in each case, the Company's experience with similar cases and various historical development patterns. Consideration is given to such historical patterns as field reserving trends and claims settlement practices, loss payments, pending levels of unpaid claims and product mix, as well as court decisions, economic conditions including inflation, and public attitudes. All of these factors can affect the estimation of claim and claim adjustment expense reserves.
	Establishing claim and claim adjustment expense reserves, including claim and claim adjustment expense reserves for catastrophic events that have occurred, is an estimation process. Many factors can ultimately affect the final settlement of a claim and, therefore, the necessary reserve. Changes in the law, results of litigation, medical costs, the cost of repair materials and labor rates can all affect ultimate claim costs. In addition, time can be a critical part of reserving determinations since the longer the span between the incidence of a loss and the payment or settlement of the claim, the more variable the ultimate settlement amount can be. Accordingly, short-tail claims, such as property damage claims, tend to be more reasonably estimable than long-tail claims, such as workers' compensation, general liability and professional liability claims. Adjustments to prior year reserve estimates, if necessary, are reflected in the results of operations in the period that the need for such adjustments is determined. There can be no assurance that the Company's ultimate cost for insurance losses will not exceed current estimates.
	Catastrophes are an inherent risk of the property and casualty insurance business and have contributed to material period-to-period fluctuations in the Company's results of operations and/or equity. The Company reported catastrophe losses, net of reinsurance, of $169 million, $391 million and $222 million for the years ended December 31, 2013, 2012 and 2011. 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.
	Reconciliation of Claim and Claim Adjustment Expense Reserves
	As of and for the years ended December 31
	(In millions)	2013			2012			2011
	Reserves, beginning of year:
	Gross	$	24,763		$	24,303		$	25,496
	Ceded	5,126			5,020			6,122
	Net reserves, beginning of year	19,637			19,283			19,374
	Change in net reserves due to acquisition (disposition) of subsidiaries	—			291			(277		)
	Net incurred claim and claim adjustment expenses:
	Provision for insured events of current year	5,114			5,273			4,904
	Decrease in provision for insured events of prior years	(115		)	(182		)	(429		)
	Amortization of discount	154			145			135
	Total net incurred (a)	5,153			5,236			4,610
	Net payments attributable to:
	Current year events	(981		)	(988		)	(1,029		)
	Prior year events	(4,588		)	(4,280		)	(3,473		)
	Total net payments	(5,569		)	(5,268		)	(4,502		)
	Foreign currency translation adjustment and other	(104		)	95			78
	Net reserves, end of year	19,117			19,637			19,283
	Ceded reserves, end of year	4,972			5,126			5,020
	Gross reserves, end of year	$	24,089		$	24,763		$	24,303
	(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) were as follows.
	Reserve Development
	Years ended December 31
	(In millions)	2013			2012			2011
	Property and casualty reserve development	$	(115	)	$	(180	)	$	(429	)
	Life reserve development in life company	—			(2		)	—
	Total	$	(115	)	$	(182	)	$	(429	)
	The following tables summarize the gross and net carried reserves as of December 31, 2013 and 2012.
	Gross and Net Carried Claim and Claim Adjustment Expense Reserves
	December 31, 2013	CNA Specialty			CNA Commercial			Hardy			Life &			Corporate			Total
	(In millions)										Group Non-Core			& Other Non-Core
	Gross Case Reserves	$	2,270		$	5,829		$	275		$	2,748		$	1,140		$	12,262
	Gross IBNR Reserves	4,419			4,820			111			310			2,167			11,827
	Total Gross Carried Claim and Claim Adjustment Expense Reserves	$	6,689		$	10,649		$	386		$	3,058		$	3,307		$	24,089
	Net Case Reserves	$	2,024		$	5,358		$	159		$	2,352		$	283		$	10,176
	Net IBNR Reserves	4,142			4,269			75			271			184			8,941
	Total Net Carried Claim and Claim Adjustment Expense Reserves	$	6,166		$	9,627		$	234		$	2,623		$	467		$	19,117
	December 31, 2012	CNA Specialty			CNA Commercial			Hardy			Life &			Corporate			Total
	(In millions)										Group Non-Core			& Other Non-Core
	Gross Case Reserves	$	2,292		$	6,146		$	333		$	2,690		$	1,207		$	12,668
	Gross IBNR Reserves	4,456			5,180			188			316			1,955			12,095
	Total Gross Carried Claim and Claim Adjustment Expense Reserves	$	6,748		$	11,326		$	521		$	3,006		$	3,162		$	24,763
	Net Case Reserves	$	2,008		$	5,611		$	192		$	2,253		$	292		$	10,356
	Net IBNR Reserves	4,104			4,600			82			275			220			9,281
	Total Net Carried Claim and Claim Adjustment Expense Reserves	$	6,112		$	10,211		$	274		$	2,528		$	512		$	19,637
	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 CNA Specialty, CNA Commercial, Hardy and Corporate & Other Non-Core segments for the years ended December 31, 2013, 2012 and 2011.
	Favorable net prior year development of $9 million, $11 million and $29 million was recorded in the Life & Group Non-Core segment for the years ended December 31, 2013, 2012 and 2011.
	Net Prior Year Development
	Year ended December 31, 2013
	(In millions)	CNA			CNA Commercial			Hardy			Corporate			Total
		Specialty									& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(230	)	$	104		$	14		$	(6	)	$	(118	)
	Pretax (favorable) unfavorable premium development	(17		)	(9		)	(17		)	1			(42		)
	Total pretax (favorable) unfavorable net prior year development	$	(247	)	$	95		$	(3	)	$	(5	)	$	(160	)
Year ended December 31, 2012
(In millions)	CNA			CNA Commercial			Hardy			Corporate			Total
	Specialty									& Other
										Non-Core
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(135	)	$	(46	)	$	(11	)	$	(13	)	$	(205	)
Pretax (favorable) unfavorable premium development	(15		)	(35		)	3			1			(46		)
Total pretax (favorable) unfavorable net prior year development	$	(150	)	$	(81	)	$	(8	)	$	(12	)	$	(251	)
Year ended December 31, 2011
(In millions)	CNA			CNA Commercial			Corporate			Total
	Specialty						& Other
							Non-Core
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(217	)	$	(204	)	$	(2	)	$	(423	)
Pretax (favorable) unfavorable premium development	(28		)	21			(1		)	(8		)
Total pretax (favorable) unfavorable net prior year development	$	(245	)	$	(183	)	$	(3	)	$	(431	)
For the year ended December 31, 2013, favorable premium development for Hardy was recorded related to a commutation as discussed later in this note.
For the year ended December 31, 2012, favorable premium development was recorded for CNA Commercial primarily due to premium adjustments on auditable policies arising from increased exposures.
For the year ended December 31, 2011, favorable premium development was recorded for CNA Specialty primarily due to changes in estimates of exposures in medical professional liability tail coverages. Unfavorable premium development for CNA Commercial was recorded due to a reduction of ultimate premium estimates relating to retrospectively rated policies, partially offset by premium adjustments on auditable policies due to increased exposures.
CNA Specialty
The following table provides further detail of the net prior year claim and allocated claim adjustment expense reserve development (development) recorded for the CNA Specialty segment for the years ended December 31, 2013, 2012 and 2011.
Years ended December 31
(In millions)	2013			2012			2011
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
Medical Professional Liability	$	(35	)	$	(32	)	$	(92	)
Other Professional Liability and Management Liability	(101		)	(22		)	(78		)
Surety	(74		)	(63		)	(47		)
Warranty	(3		)	(5		)	(13		)
Other	(17		)	(13		)	13
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(230	)	$	(135	)	$	(217	)
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 CNA 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, favorable development for other professional liability and management liability was primarily due to better than expected loss emergence in accident years 2003 through 2007. Unfavorable development was recorded in our lawyer coverages in accident years 2010 and 2011 primarily due to increased frequency and severity.
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.
2011
Favorable development for medical professional liability was primarily due to favorable case incurred emergence in nurses, physicians, excess institutions and primary institutions in accident years 2008 and prior.
Favorable development for other professional liability and management liability was driven by better than expected loss emergence in the life agents, accountants, and architects & engineers business in accident years 2008 and prior. In addition, favorable development in the Company's European book of business was primarily due to favorable outcomes on several large losses in financial directors and officers and errors and omissions coverages in accident years 2003 and prior.
Favorable development for surety coverages was primarily due to a decrease in the estimated loss on a large national contractor in accident year 2005 and better than expected loss emergence in accident years 2009 and prior.
Favorable development in warranty was driven by favorable policy year experience on an aggregate stop loss policy covering the Company's non-insurance warranty subsidiary.
Unfavorable development for other coverages was primarily due to increased frequency of large claims in auto and workers' compensation coverages in accident years 2009 and 2010.
CNA Commercial
The following table provides further detail of the development recorded for the CNA Commercial segment for the years ended December 31, 2013, 2012 and 2011.
Years ended December 31
(In millions)	2013			2012			2011
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
Commercial Auto	$	15		$	27		$	(98	)
General Liability	59			(64		)	(39		)
Workers' Compensation	92			15			36
Property and Other	(62		)	(24		)	(103		)
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	104		$	(46	)	$	(204	)
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 Defense Base Act 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.
Overall, favorable development for property and other coverages was due to a favorable outcome on an individual claim in accident year 2005 and favorable loss emergence in non-catastrophe losses in accident years 2009 and 2010. Unfavorable development was recorded in accident year 2011 related to several large losses.
2011
Favorable development for commercial auto coverages was due to lower than expected severity on bodily injury claims and favorable claim emergence on umbrella policies in accident years 2006 and prior.
Favorable development in the general liability coverages was primarily due to favorable claim emergence in accident years 2007 and prior related to both primary and umbrella liability coverages.
Unfavorable development for workers' compensation was related to increased medical severity in accident year 2010.
Overall, favorable development for property and other coverages was due to decreased frequency of large losses in commercial multi-peril coverages primarily in accident year 2010, favorable loss emergence related to catastrophe claims in accident year 2008 and favorable loss emergence related to non-catastrophe claims in accident years 2010 and prior. This development amount also included unfavorable development related to unallocated claim adjustment expenses.
Hardy
The following table provides further detail of the development recorded for the Hardy segment for the years ended December 31, 2013 and 2012.
Years ended December 31
(In millions)	2013			2012
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
Marine and Aviation	$	2		$	—
Non-Marine Property	12			(7		)
Property Treaty	(5		)	(3		)
Specialty	(6		)	(1		)
Commutation	11			—
Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	14		$	(11	)
2013
Unfavorable development for non-marine property 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 for property treaty was due to favorable emergence of losses from catastrophe and non-catastrophe claims in 2011 and 2012.
Favorable development for specialty was primarily due to favorable outcomes on several large losses and favorable claim emergence.
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.
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)	2013			2012			2011
Net A&EP adverse development before consideration of LPT	$	363		$	261		$	84
Provision for uncollectible third-party reinsurance on A&EP	140			—			—
Additional amounts ceded under LPT	503			261			84
Retroactive reinsurance benefit recognized	(314		)	(261		)	(84		)
Pretax impact of unrecognized deferred retroactive reinsurance benefit	$	189		$	—		$	—
During 2013, 2012, and 2011, 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 Loss Portfolio Transfer is a retroactive reinsurance contract. In the event that the cumulative claim and allocated claim adjustment expenses ceded under the Loss Portfolio Transfer exceed the consideration paid, the resulting gain from such excess is deferred. A portion of the deferred gain is cumulatively recognized in earnings in the period such excess arises as if the revised estimate was available at the inception date of the Loss Portfolio Transfer.
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 will be recognized in earnings in future periods 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.
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, 2013 was $3.1 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, 2013
Legal Proceedings and Contingent Liabilities [Abstract]	'
Legal Proceedings and Contingent Liabilities	'
	Note G. Legal Proceedings and Contingent Liabilities
	The Company is a party to routine litigation incidental to its business, which, based on the facts and circumstances currently known, is not material to the Consolidated Financial Statements.

Reinsurance

Reinsurance	12 Months Ended
	Dec. 31, 2013
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, 2013 and 2012.
	Components of Reinsurance Receivables
	31-Dec
	(In millions)	2013			2012
	Reinsurance receivables related to insurance reserves:
	Ceded claim and claim adjustment expenses	$	4,972		$	5,126
	Ceded future policy benefits	733			759
	Ceded policyholders' funds	35			35
	Reinsurance receivables related to paid losses	348			311
	Reinsurance receivables	6,088			6,231
	Allowance for uncollectible reinsurance	(71		)	(73		)
	Reinsurance receivables, net of allowance for uncollectible reinsurance	$	6,017		$	6,158
	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 $3.9 billion and $3.7 billion at December 31, 2013 and 2012.
	The Company's largest recoverables from a single reinsurer at December 31, 2013, including prepaid reinsurance premiums, were approximately $2.9 billion from subsidiaries of Berkshire Hathaway Group, $850 million from subsidiaries of Swiss Re Group, and $350 million from subsidiaries of the Hartford Insurance Group. 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.
	The effects of reinsurance on earned premiums and written premiums for the years ended December 31, 2013, 2012 and 2011 are shown in the following tables.
	Components of Earned Premiums
	(In millions)	Direct			Assumed			Ceded		Net		Assumed/
												Net %
	2013 Earned Premiums
	Property and casualty	$	9,063		$	258		$	2,609	$	6,712	3.8	%
	Accident and health	512			48			1		559		8.6	%
	Life	49			—			49		—		—
	Total earned premiums	$	9,624		$	306		$	2,659	$	7,271	4.2	%
	2012 Earned Premiums
	Property and casualty	$	8,354		$	197		$	2,229	$	6,322	3.1	%
	Accident and health	514			47			1		560		8.4	%
	Life	51			—			51		—		—
	Total earned premiums	$	8,919		$	244		$	2,281	$	6,882	3.5	%
	2011 Earned Premiums
	Property and casualty	$	7,858		$	95		$	1,919	$	6,034	1.6	%
	Accident and health	521			50			2		569		8.8	%
	Life	55			—			55		—		—
	Total earned premiums	$	8,434		$	145		$	1,976	$	6,603	2.2	%
	Components of Written Premiums
	(In millions)	Direct			Assumed			Ceded		Net		Assumed/
												Net %
	2013 Written Premiums
	Property and casualty	$	9,103		$	249		$	2,556	$	6,796	3.7	%
	Accident and health	506			47			1		552		8.5	%
	Life	49			—			49		—		—
	Total written premiums	$	9,658		$	296		$	2,606	$	7,348	4	%
	2012 Written Premiums
	Property and casualty	$	8,467		$	169		$	2,225	$	6,411	2.6	%
	Accident and health	507			47			1		553		8.5	%
	Life	51			—			51		—		—
	Total written premiums	$	9,025		$	216		$	2,277	$	6,964	3.1	%
	2011 Written Premiums
	Property and casualty	$	7,976		$	102		$	1,857	$	6,221	1.6	%
	Accident and health	529			50			2		577		8.7	%
	Life	55			—			55		—		—
	Total written premiums	$	8,560		$	152		$	1,914	$	6,798	2.2	%
	Included in the direct and ceded earned premiums for the years ended December 31, 2013, 2012 and 2011 are $2,156 million, $1,794 million and $1,500 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.
	Life and accident and health premiums are primarily from long duration contracts; property and casualty premiums are primarily from short duration contracts.
	Insurance claims and policyholders' benefits reported on the Consolidated Statements of Operations are net of reinsurance recoveries of $1,527 million, $1,514 million and $1,285 million for the years ended December 31, 2013, 2012 and 2011, including $712 million, $814 million and $790 million related to the significant third-party captive program discussed above.
	The impact of reinsurance on life insurance inforce at December 31, 2013, 2012 and 2011 is shown in the following table.
	Components of Life Insurance Inforce
	(In millions)	Direct			Assumed			Ceded		Net
	2013	$	5,127		$	—		$	5,118	$	9
	2012	5,713			—			5,702		11
	2011	6,528			—			6,515		13
As of December 31, 2013 and 2012, the Company has ceded $1,066 million and $1,131 million of claim and claim adjustment expense reserves, future policy benefits and policyholders' funds as a result of business operations sold in prior years. Subject to certain exceptions, the purchasers assumed the third-party reinsurance credit risk of the sold business.

Debt

Debt	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Debt Disclosure [Text Block]	'
	Note I. Debt
	Debt is composed of the following obligations.
	Debt
	31-Dec
	(In millions)	2013			2012
	Short term debt:
	Senior notes of CNAF, 5.850%, face amount of $549, due December 15, 2014	$	549		$	—
	Other debt	—			13
	Total short term debt	549			13
	Long term debt:
	Senior notes of CNAF:
	5.850%, face amount of $549, due December 15, 2014	—			548
	6.500%, face amount of $350, due August 15, 2016	349			348
	6.950%, face amount of $150, due January 15, 2018	149			149
	7.350%, face amount of $350, due November 15, 2019	348			348
	5.875%, face amount of $500, due August 15, 2020	497			496
	5.750%, face amount of $400, due August 15, 2021	397			397
	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	2,011			2,557
	Total debt	$	2,560		$	2,570
	In 2013, CCC became 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 acquired $16 million of FHLBC stock giving it access to approximately $330 million of additional liquidity. As of December 31, 2013, CCC has no outstanding borrowings from the FHLBC.
	In 2012, the Company entered into a credit agreement with a syndicate of banks. The credit agreement established a four-year $250 million senior unsecured revolving credit facility 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, and there is an option to extend the facility for an additional year prior to the second anniversary of the closing date subject to applicable consents. 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, 2013, was $8.2 billion. As of December 31, 2013, we had no outstanding borrowings under the credit agreement.
	The Company's remaining debt obligations contain customary covenants for investment grade issuers. The Company is in compliance with all covenants as of and for the year ended December 31, 2013.
	The combined aggregate maturities for debt at December 31, 2013 are presented in the following table.
	Maturity of Debt
	(In millions)
	2014	$	549
	2015	—
	2016	350
	2017	—
	2018	150
	Thereafter	1,523
	Less discount	(12		)
	Total	$	2,560

Benefit_Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
Benefit Plans	'
	Note J. Benefit Plans
	Pension and Postretirement Health Care Benefit Plans
	CNA sponsors noncontributory pension plans, primarily through the CNA Retirement Plan, typically covering full-time employees age 21 and over that have completed at least one year or 1,000 hours of service.
	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.
	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 benefits have largely been eliminated for active employees.
	The following table provides a reconciliation of benefit obligations and plan assets for the years ended December 31, 2013 and 2012.
	Funded Status
		Pension Benefits								Postretirement Benefits
	(In millions)	2013				2012				2013			2012
	Benefit obligation at January 1	$	3,271			$	3,003			$	47		$	49
	Changes in benefit obligation:
	Service cost	12				12				1			—
	Interest cost	121				135				1			2
	Participants' contributions	—				—				5			5
	Actuarial (gain) loss	(289		)		266				(3		)	3
	Benefits paid	(165		)		(164		)		(12		)	(12		)
	Settlements	(8		)		—				—			—
	Foreign currency translation and other	1				19				1			—
	Benefit obligation at December 31	2,943				3,271				40			47
	Fair value of plan assets at January 1	2,425				2,212				—			—
	Change in plan assets:
	Actual return on plan assets	311				245				—			—
	Company contributions	92				115				7			7
	Participants' contributions	—				—				5			5
	Benefits paid	(165		)		(164		)		(12		)	(12		)
	Settlements	(8		)		—				—			—
	Foreign currency translation and other	1				17				—			—
	Fair value of plan assets at December 31	2,656				2,425				—			—
	Funded status	$	(287	)		$	(846	)		$	(40	)	$	(47	)
	Amounts recognized on the Consolidated Balance Sheets at December 31:
	Other assets	$	9			$	—			$	—		$	—
	Other liabilities	(296		)		(846		)		(40		)	(47		)
	Net amount recognized	$	(287	)		$	(846	)		$	(40	)	$	(47	)
	Amounts recognized in Accumulated other comprehensive income, not yet recognized in net periodic cost (benefit):
	Prior service credit	$	—			$	—			$	(98	)	$	(116	)
	Net actuarial loss	745				1,213				8			11
	Net amount recognized	$	745			$	1,213			$	(90	)	$	(105	)
	The accumulated benefit obligation for all defined benefit pension plans was $2,889 million and $3,187 million at December 31, 2013 and 2012.
	The components of net periodic cost (benefit) are presented in the following table.
	Net Periodic Cost (Benefit)
	Years ended December 31
	(In millions)	2013				2012				2011
	Pension cost (benefit)
	Service cost	$	12			$	12			$	13
	Interest cost on projected benefit obligation	121				135				146
	Expected return on plan assets	(181		)		(171		)		(172		)
	Amortization of net actuarial (gain) loss	47				39				25
	Settlement loss	3				—				—
	Net periodic pension cost (benefit)	$	2			$	15			$	12
	Postretirement cost (benefit)
	Service cost	$	1			$	—			$	1
	Interest cost on projected benefit obligation	1				2				3
	Amortization of prior service credit	(18		)		(18		)		(19		)
	Amortization of net actuarial (gain) loss	2				1				—
	Net periodic postretirement cost (benefit)	$	(14	)		$	(15	)		$	(15	)
	The amounts recognized in Other comprehensive income are presented in the following table.
	Years ended December 31
	(In millions)	2013				2012				2011
	Pension and postretirement benefits
	Amounts arising during the period	$	422			$	(195	)		$	(325	)
	Reclassification adjustment relating to prior service credit	(18		)		(18		)		(19		)
	Reclassification adjustment relating to actuarial loss	49				40				25
Total increase (decrease) in Other comprehensive income	$	453			$	(173	)		$	(319	)
The table below presents the estimated amounts to be recognized from Accumulated other comprehensive income into net periodic cost (benefit) during 2014.
(In millions)		Pension				Postretirement Benefits
		Benefits
Amortization of prior service credit		$	—			$	(18	)
Amortization of net actuarial loss		25				—
Total estimated amounts to be recognized		$	25			$	(18	)
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	2013			2012
Pension benefits
Discount rate	4.65	%		3.8	%
Expected long term rate of return	7.5			7.75
Rate of compensation increases	3.99			4.066
Postretirement benefits
Discount rate	3.6	%		2.8	%
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	2013			2012			2011
Pension benefits
Discount rate	3.8	%		4.6	%		5.375	%
Expected long term rate of return	7.75			8			8
Rate of compensation increases	4.066			4.125			5.03
Postretirement benefits
Discount rate	2.8	%		3.75	%		4.375	%
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 2013, 2012 and 2011.
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 plan assets for a prudent level of risk and to manage cash flows according to plan requirements. The intent of this strategy is to minimize the Company's expense related to funding the plan by outperforming 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, 2013, the plan had committed approximately $102 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 are summarized below.
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
December 31, 2012
(In millions)		Level 1				Level 2				Level 3			Total Assets
													at Fair Value
Assets
Fixed maturity securities:
Corporate and other bonds		$	—			$	436			$	11		$	447
States, municipalities and political subdivisions		—				91				—			91
Asset-backed:
Residential mortgage-backed		—				161				—			161
Commercial mortgage-backed		—				105				—			105
Total asset-backed		—				266				—			266
Total fixed maturity securities		—				793				11			804
Equity securities		386				102				5			493
Derivative financial instruments		1				—				—			1
Short term investments		37				82				—			119
Limited partnerships:
Hedge funds		—				537				359			896
Private equity		—				—				62			62
Total limited partnerships		—				537				421			958
Other assets		—				40				—			40
Investment contracts with insurance company		—				—				10			10
Total assets		$	424			$	1,554			$	447		$	2,425
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 58% are equity related, 37% pursue a multi-strategy approach and 5% are focused on distressed investments at December 31, 2013.
The fair value of the insurance company guaranteed investment contracts is an estimate of the amount that would be received in an orderly sale to a market participant at the measurement date. The amount the plan would receive from the contract holder if the contracts were terminated is the primary input and is unobservable. The guaranteed investment contracts are therefore classified as Level 3 investments.
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.
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, 2013 and 2012.
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
Level 3	Balance at January 1, 2012				Actual return on assets still held at December 31, 2012				Actual return on assets sold during the year ended December 31, 2012			Purchases, sales, and settlements			Net transfers into (out of) Level 3			Balance at December 31, 2012
(In millions)
Fixed maturity securities:
Corporate and other bonds	$	10			$	1			$	—		$	—		$	—		$	11
Equity securities	5				—				—			—			—			5
Limited partnerships:
Hedge funds	330				41				3			(15		)	—			359
Private equity	65				8				—			(11		)	—			62
Total limited partnerships	395				49				3			(26		)	—			421
Investment contracts with insurance company	10				—				—			—			—			10
Total	$	420			$	50			$	3		$	(26	)	$	—		$	447
The table below presents the estimated future minimum benefit payments to participants at December 31, 2013.
Estimated Future Minimum Benefit Payments to Participants
(In millions)	Pension Benefits				Postretirement Benefits
2014	$	189			$	5
2015	191				4
2016	194				5
2017	199				4
2018	203				4
2019-2023	1,013				14
In 2014, CNA expects to contribute $56 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 20% 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.
The CNA Savings and Capital Accumulation Plan allows employees to make contributions to an investment fund that is supported in part by an investment contract purchased from CAC. CAC will not accept any further deposits under this contract. The liability to the CNA Savings and Capital Accumulation Plan is included in Separate account liabilities on the Consolidated Balance Sheets, and was $129 million and $256 million at December 31, 2013 and 2012.
As noted above, during 2000, CCC employees were required to make a choice regarding their continued participation in CNA's defined benefit pension plan. Employees who elected to forgo earning additional benefits in the defined benefit pension plan and all employees hired by CCC 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 $71 million, $70 million and $60 million for the years ended December 31, 2013, 2012 and 2011.
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, 2013 was approximately 1.5 million.
The Company recorded stock-based compensation expense related to the Plan of $10 million, $9 million and $6 million for the years ended December 31, 2013, 2012 and 2011. The related income tax benefit recognized was $3 million, $3 million and $2 million. The compensation cost related to nonvested awards not yet recognized was $14 million, and the weighted average period over which it is expected to be recognized is 1.7 years at December 31, 2013.
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.
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 year ended December 31, 2013. The following table presents the significant assumptions used to estimate the fair value of granted stock options and SARs for the years ended December 31, 2012 and 2011.
Years ended December 31	2012			2011
Weighted average expected life of the securities granted (in years)	5.68			5.61
Estimate of the underlying common stock's volatility	40.39	%		39.88	%
Expected dividend yield	2.1	%		1.5	%
Risk free interest rate	1	%		2.2	%
The following table presents activity for stock options and SARs under the Plan in 2013.
		Number of Awards			Weighted-Average Exercise Price per Award				Aggregate Intrinsic Value			Weighted-Average Remaining Contractual Term (in years)
Outstanding at January 1, 2013		1,158,700			$	25.93
Awards granted		—			—
Awards exercised		(117,950	)		21.19
Awards forfeited, canceled or expired		(4,100	)		30.66
Outstanding at December 31, 2013		1,036,650			$	26.45			$	17	million	4.16
Outstanding, fully vested and expected to vest		1,032,849			$	26.45			$	17	million	4.15
Outstanding, exercisable		936,650			$	26.42			$	15	million	3.87
The following table presents weighted-average grant date fair value for awards granted, total intrinsic value for awards exercised and total fair value for awards vested for the years ended December 31, 2013, 2012 and 2011.
Years ended December 31	2013				2012				2011
Weighted-average grant date fair value					$	8.81			$	9.38
Total intrinsic value of awards exercised	$	1,495	thousand		$	548	thousand		$	481	thousand
Fair value of awards vested	$	1	million		$	1	million		$	2	million
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 restricted shares, performance-based RSUs and performance share units under the Plan in 2013.
	Number of Awards			Weighted-Average Grant Date Fair Value
Balance at January 1, 2013	882,321			$	26.15
Awards granted	351,364			31.8
Awards vested	(417,955	)		24.04
Awards forfeited, canceled or expired	(13,770	)		28.72
Performance-based adjustment	45,714			28.39
Balance at December 31, 2013	847,674			$	29.61

Other_Intangible_Assets

Other Intangible Assets	12 Months Ended
	Dec. 31, 2013
Intangible Assets, Gross (Excluding Goodwill) [Abstract]	'
Other Intangible Assets	'
	Note K. Other Intangible Assets
	Other intangible assets are presented in the following table.
			31-Dec-13				31-Dec-12
	(In millions)	Economic Useful Life	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
	Finite-lived intangible assets:
	Value of business acquired	1 - 4 years	$	64	$	63	$	62	$	43
	Trade name	8 years	8		2		8		—
	Distribution channel	15 years	13		1		13		—
	Total finite-lived intangible assets		85		66		83		43
	Indefinite-lived intangible assets:
	Syndicate capacity		58				57
	Agency force		16				16
	Total indefinite-lived intangible assets		74				73
	Total other intangible assets		$	159	$	66	$	156	$	43
	For the years ended December 31, 2013 and 2012, amortization expense of $15 million and $33 million was included in Amortization of deferred acquisition costs and $5 million and $10 million was included in Other operating expenses in the Statement of Operations for the Hardy segment. The gross carrying amounts and accumulated amortization in the table above may change from period to period as a result of foreign currency translation. Estimated future amortization expense for intangible assets is $4 million in 2014, $1 million in 2015 and $2 million in years 2016, 2017 and 2018.

Operating_Leases_Commitments_a

Operating Leases, Commitments and Contingencies, and Guarantees	12 Months Ended
	Dec. 31, 2013
Operating Leases, Commitments and Contingencies, and Guarantees [Abstract]	'
Operating Leases, Commitments and Contingencies, and Guarantees	'
	Note L. 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, 2013, 2012 and 2011 were $46 million, $52 million and $50 million. Sublease revenues for the years ended December 31, 2013, 2012 and 2011 were $3 million, $2 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, 2013.
	Future Minimum Lease Payments and Sublease Receipts
	(In millions)	Future Minimum Lease Payments		Future Minimum Sublease Receipts
	2014	$	37	$	2
	2015	32		—
	2016	29		—
	2017	23		—
	2018	17		—
	Thereafter	70		—
	Total	$	208	$	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, 2013 that the Company could be required to pay under this guarantee, in excess of amounts already recorded, were approximately $84 million. If the Company were required to assume the entire lease obligation, the Company would have the right to pursue reimbursement from the other shareholders and the right to all sublease revenues.
	Guarantees
	In the course of selling business entities and assets to third parties, the Company has agreed to indemnify purchasers for losses arising out of breaches of representation and warranties with respect to the business entities or assets being sold, including, in certain cases, losses arising from undisclosed liabilities or certain named litigation. Such indemnification agreements may include provisions that survive indefinitely. As of December 31, 2013, the aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third-party loans was $702 million.
	In addition, the Company has agreed to provide indemnification to third-party purchasers for certain losses associated with sold business entities or assets that are not limited by a contractual monetary amount. As of December 31, 2013, the Company had outstanding unlimited indemnifications in connection with the sales of certain of its business entities or assets that included tax liabilities arising prior to a purchaser's ownership of an entity or asset, defects in title at the time of sale, employee claims arising prior to closing and in some cases losses arising from certain litigation and undisclosed liabilities. These indemnification agreements survive until the applicable statutes of limitation expire or until the agreed upon contract terms expire.
	As of December 31, 2013 and 2012, the Company had recorded liabilities of approximately $7 million related to indemnification agreements and management believes that it is not likely that any future indemnity claims will be significantly greater than the amounts recorded.

Stockholders_Equity_and_Statut

Stockholders' Equity and Statutory Accounting Practices	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity and Statutory Accounting Practices [Abstract]	'
Stockholders' Equity And Statutory Accounting Practices	'
	Note M. 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 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, may be paid only from earned surplus, which is calculated by removing unrealized gains from unassigned surplus. As of December 31, 2013, CCC is in a positive earned surplus position, enabling CCC to pay approximately $715 million of dividend payments during 2014 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)	2013 (b)		2012		2013 (b)		2012		2011
	Combined Continental Casualty Companies (a)	$	11,137	$	9,998	$	913	$	391	$	954
	Life company	597		556		48		44		29
	________________
	(a)	Represents the combined statutory surplus of CCC and its subsidiaries, including the life company.
	(b)	Information derived from the statutory-basis financial statements to be filed with insurance regulators.
	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 265% and 240% of company action level RBC at December 31, 2013 and 2012. 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 insurance 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, 2013, Hardy's portion of Syndicate 382's capital requirement included $148 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, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Accumulated Other Comprehensive Income (Loss) by Component	'
	Note N. Accumulated Other Comprehensive Income (Loss) by Component
	The table below displays the changes in Accumulated other comprehensive income (loss) by component for the year ended December 31, 2013.
		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 of $0, $(10), $11, $0, and $1	—			21			(20		)	—			1
	Other comprehensive income (loss) after tax of $(3), $364, $(158), $0, and $203	6			(679		)	295			(11		)	(389		)
	Balance at December 31, 2013	$	26		$	692		$	(426	)	$	150		$	442
	The following table displays the components of AOCI included on the Consolidated Balance Sheet for the year ended December 31, 2012.
	31-Dec	2012
	(In millions)	Tax			After-tax
	Cumulative foreign currency translation adjustment	$	—		$	161
	Pension and postretirement benefits	387			(721		)
	Net unrealized gains (losses) on investments with OTTI losses	(11		)	20
	Net unrealized gains (losses) on other investments	(721		)	1,371
	Accumulated other comprehensive income (loss)	$	(345	)	$	831
	The amount of pretax net unrealized gains (losses) on available-for-sale securities with OTTI losses reclassified out of AOCI into earnings was $(28) million and $(83) million for the years ended December 31, 2012 and 2011, with related tax benefit of $10 million and $29 million. The amount of pretax net unrealized gains (losses) on other available-for-sale securities reclassified out of AOCI into earnings was $89 million and $60 million for the years ended December 31, 2012 and 2011, with related tax (expense) benefit of $(31) million and $(21) million.
	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)
	Pension and postretirement benefits		Other operating expenses

Business_Segments

Business Segments	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Business Segments	'
	Note O. Business Segments
	The Company's core property and casualty commercial insurance operations are reported in three business segments: CNA Specialty, CNA Commercial and Hardy. CNA Specialty provides a broad array of professional, financial and specialty property and casualty products and services, primarily through insurance brokers and managing general underwriters. CNA Commercial includes property and casualty coverages sold to small businesses and middle market entities and organizations primarily through an independent agency distribution system. CNA Commercial also includes commercial insurance and risk management products sold to large corporations primarily through insurance brokers. Hardy, a specialized Lloyd's underwriter, underwrites primarily short-tail exposures in marine and aviation, non-marine property, specialty lines and property treaty reinsurance.
	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 the life and group lines of business 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. The Company manages most of its assets on a legal entity basis, while segment operations are generally conducted across legal entities. As such, only insurance and reinsurance receivables, insurance reserves, deferred acquisition costs and goodwill are readily identifiable for all individual segments. Distinct investment portfolios are not maintained for every individual segment; accordingly, allocation of assets to each segment is not performed. Therefore, a significant portion of net investment income and realized investment gains or losses are allocated primarily based on each segment's net carried insurance reserves, as adjusted. All significant intersegment income and expense has been eliminated. Income taxes have been allocated on the basis of the taxable income of the segments.
	Approximately 8.9%, 9.2% and 8.8% of the Company's direct written premiums were derived from outside the United States for the years ended December 31, 2013, 2012 and 2011.
	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) attributable to CNA 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, 2013	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Net written premiums (a)	$	3,091		$	3,312		$	396		$	552		$	(1	)	$	(2	)	$	7,348
	Operating revenues
	Net earned premiums	$	3,004		$	3,350		$	361		$	559		$	(1	)	$	(2	)	$	7,271
	Net investment income	657			927			4			830			32			—			2,450
	Other revenues	257			96			—			(2		)	12			(2		)	361
	Total operating revenues	3,918			4,373			365			1,387			43			(4		)	10,082
	Claims, Benefits and Expenses
	Net incurred claims and benefits	1,704			2,475			162			1,395			191			—			5,927
	Policyholders’ dividends	6			7			—			7			—			—			20
	Amortization of deferred acquisition costs	628			600			106			28			—			—			1,362
	Other insurance related expenses	272			547			69			134			(3		)	(2		)	1,017
	Other expenses	236			26			19			12			183			(2		)	474
	Total claims, benefits and expenses	2,846			3,655			356			1,576			371			(4		)	8,800
	Operating income (loss) from continuing operations before income tax	1,072			718			9			(189		)	(328		)	—			1,282
	Income tax (expense) benefit on operating income (loss)	(365		)	(250		)	1			131			118			—			(365		)
	Net operating income (loss) from continuing operations attributable to CNA	707			468			10			(58		)	(210		)	—			917
	Net realized investment gains (losses), pretax	(3		)	(13		)	1			37			9			—			31
	Income tax (expense) benefit on net realized investment gains (losses)	1			4			—			(13		)	(3		)	—			(11		)
	Net realized investment gains (losses)	(2		)	(9		)	1			24			6			—			20
	Net income (loss) from continuing operations attributable to CNA	$	705		$	459		$	11		$	(34	)	$	(204	)	$	—		$	937
	____________________
	(a)	Related to business in property and casualty companies only.
	December 31, 2013
	(In millions)
	Reinsurance receivables	$	546		$	1,075		$	197		$	1,203		$	3,067		$	—		$	6,088
	Insurance receivables	$	775		$	1,099		$	176		$	11		$	2		$	—		$	2,063
	Deferred acquisition costs	$	318		$	257		$	49		$	—		$	—		$	—		$	624
	Goodwill	$	117		$	—		$	38		$	—		$	—		$	—		$	155
	Insurance reserves
	Claim and claim adjustment expenses	$	6,689		$	10,649		$	386		$	3,058		$	3,307		$	—		$	24,089
	Unearned premiums	1,805			1,536			249			128			—			—			3,718
	Future policy benefits	—			—			—			10,471			—			—			10,471
	Policyholders’ funds	9			15			—			92			—			—			116
	Year ended December 31, 2012	CNA			CNA			Hardy(b)			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Net written premiums (a)	$	2,924		$	3,373		$	117		$	553		$	(1	)	$	(2	)	$	6,964
	Operating revenues
	Net earned premiums	$	2,898		$	3,306		$	120		$	560		$	—		$	(2	)	$	6,882
	Net investment income	592			854			3			801			32			—			2,282
	Other revenues	230			40			1			34			16			(1		)	320
	Total operating revenues	3,720			4,200			124			1,395			48			(3		)	9,484
	Claims, Benefits and Expenses
	Net incurred claims and benefits	1,831			2,574			72			1,406			(16		)	—			5,867
	Policyholders’ dividends	2			11			—			16			—			—			29
	Amortization of deferred acquisition costs	614			588			44			28			—			—			1,274
	Other insurance related expenses	301			578			25			144			3			(2		)	1,049
	Other expenses	206			36			9			23			183			(1		)	456
	Total claims, benefits and expenses	2,954			3,787			150			1,617			170			(3		)	8,675
	Operating income (loss) from continuing operations before income tax	766			413			(26		)	(222		)	(122		)	—			809
	Income tax (expense) benefit on operating income (loss)	(262		)	(136		)	3			132			41			—			(222		)
	Net operating income (loss) from continuing operations attributable to CNA	504			277			(23		)	(90		)	(81		)	—			587
Net realized investment gains (losses), pretax	22			38			(1		)	—			4			—			63
Income tax (expense) benefit on net realized investment gains (losses)	(9		)	(11		)	—			—			(2		)	—			(22		)
Net realized investment gains (losses)	13			27			(1		)	—			2			—			41
Net income (loss) from continuing operations attributable to CNA	$	517		$	304		$	(24	)	$	(90	)	$	(79	)	$	—		$	628
____________________
(a)	Related to business in property and casualty companies only.
(b)	Included from date of acquisition.
December 31, 2012
(In millions)
Reinsurance receivables	$	665		$	1,155		$	294		$	1,273		$	2,844		$	—		$	6,231
Insurance receivables	$	673		$	1,116		$	181		$	9		$	4		$	—		$	1,983
Deferred acquisition costs	$	300		$	269		$	29		$	—		$	—		$	—		$	598
Goodwill	$	117		$	—		$	37		$	—		$	—		$	—		$	154
Insurance reserves
Claim and claim adjustment expenses	$	6,748		$	11,326		$	521		$	3,006		$	3,162		$	—		$	24,763
Unearned premiums	1,685			1,569			222			134			—			—			3,610
Future policy benefits	—			—			—			11,475			—			—			11,475
Policyholders’ funds	8			15			—			134			—			—			157
Year ended December 31, 2011	CNA			CNA			Life &			Corporate
	Specialty			Commercial			Group			& Other
(In millions)							Non-Core			Non-Core			Eliminations			Total
Net written premiums (a)	$	2,872		$	3,350		$	577		$	2		$	(3	)	$	6,798
Operating revenues
Net earned premiums	$	2,796		$	3,240		$	569		$	1		$	(3	)	$	6,603
Net investment income	500			763			759			32			—			2,054
Other revenues	221			54			13			6			—			294
Total operating revenues	3,517			4,057			1,341			39			(3		)	8,951
Claims, Benefits and Expenses
Net incurred claims and benefits	1,657			2,296			1,526			(3		)	—			5,476
Policyholders’ dividends	(3		)	8			8			—			—			13
Amortization of deferred acquisition costs	568			585			23			—			—			1,176
Other insurance related expenses	294			540			143			6			(3		)	980
Other expenses	191			53			19			170			—			433
Total claims, benefits and expenses	2,707			3,482			1,719			173			(3		)	8,078
Operating income (loss) from continuing operations before income tax	810			575			(378		)	(134		)	—			873
Income tax (expense) benefit on operating income (loss)	(281		)	(204		)	170			68			—			(247		)
Net operating (income) loss, after-tax, attributable to noncontrolling interests	(12		)	(4		)	—			—			—			(16		)
Net operating income (loss) from continuing operations attributable to CNA	517			367			(208		)	(66		)	—			610
Net realized investment gains (losses), pretax	(5		)	16			(7		)	(6		)	—			(2		)
Income tax (expense) benefit on net realized investment gains (losses)	2			(2		)	2			3			—			5
Net realized investment gains (losses)	(3		)	14			(5		)	(3		)	—			3
Net income (loss) from continuing operations attributable to CNA	$	514		$	381		$	(213	)	$	(69	)	$	—		$	613
____________________
(a)	Related to business in property and casualty companies only.
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)	2013			2012			2011
CNA Specialty
International	$	239		$	220		$	210
Management & Professional Liability	2,836			2,723			2,541
Surety	490			485			472
Warranty & Alternative Risks	350			314			289
CNA Specialty revenues	3,915			3,742			3,512
CNA Commercial
Commercial Insurance	3,230			3,200			2,953
International	376			369			539
Small Business	754			669			581
CNA Commercial revenues	4,360			4,238			4,073
Hardy revenues	366			123
Life & Group Non-Core
Health	1,192			1,120			1,093
Life & Annuity	232			239			229
Other	—			36			12
Life & Group Non-Core revenues	1,424			1,395			1,334
Corporate & Other Non-Core revenues	52			52			33
Eliminations	(4		)	(3		)	(3		)
Total revenues	$	10,113		$	9,547		$	8,949

Quarterly_Financial_Data_Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Data [Abstract]	'
Quarterly Financial Data (Unaudited)	'
	Note P. Quarterly Financial Data (Unaudited)
	The following tables set forth unaudited quarterly financial data for the years ended December 31, 2013 and 2012.
	Quarterly Financial Data
	2013
	(In millions, except per share data)	First		Second		Third		Fourth			Full Year
	Revenues	$	2,503	$	2,493	$	2,504	$	2,613		$	10,113
	Net income (loss) attributable to CNA	$	250	$	194	$	272	$	221		$	937
	Basic earnings (loss) per share attributable to CNA common stockholders	$	0.93	$	0.72	$	1.01	$	0.82		$	3.48
	Diluted earnings (loss) per share attributable to CNA common stockholders (a)	$	0.93	$	0.72	$	1.01	$	0.82		$	3.47
	2012
	(In millions, except per share data)	First		Second		Third		Fourth			Full Year
	Revenues	$	2,401	$	2,246	$	2,466	$	2,434		$	9,547
	Net income (loss) attributable to CNA	$	250	$	166	$	221	$	(9	)	$	628
	Basic and diluted earnings (loss) per share attributable to CNA common stockholders (a)	$	0.93	$	0.62	$	0.82	$	(0.03	)	$	2.33
	____________________
	(a)	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, 2013
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	Note Q. Related Party Transactions
	The Company reimburses Loews, or pays directly, for management fees, travel and related expenses, software fees, and expenses of investment facilities and services provided to the Company. The amounts reimbursed or paid by the Company were $39 million for the years ended December 31, 2013 and 2012, and $38 million for the year ended December 31, 2011. The CNA Tax Group is included in the consolidated federal income tax return of Loews and its eligible subsidiaries. See Note E for a detailed description of the income tax agreement with Loews. 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, 2013, 2012 and 2011 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, compounded semi-annually, in effect on the disbursement date of the loan. Loans made pursuant to the plan are generally full recourse and are secured by the stock purchased. The loans were originally issued with a ten-year maturity date, and the majority of the remaining loans have been extended with current terms maturing through May 2016.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2013
Subsequent Events [Abstract]	'
Subsequent Events [Text Block]	'
	Note R. Subsequent Event
	On February 10, 2014, the Company entered into a definitive agreement to sell the majority of its run-off annuity and pension deposit business, through the sale of the common stock of CAC, and a 100% coinsurance agreement on a separate small block of annuity business outside of CAC.
	The business being sold is currently reported within the Life & Group Non-Core segment. As of December 31, 2013, gross insurance reserves for this business were approximately $3.4 billion. Results for this business were net income of approximately $31 million and $8 million for the years ended December 31, 2013 and 2012, and a net loss of approximately $124 million for the year ended December 31, 2011.
	The sale is subject to regulatory approvals and other customary closing conditions and is expected to close in the first half of 2014. An impairment loss of approximately $220 million, after-tax, will be recorded in the first quarter of 2014.  This business will be reported as discontinued operations in the first quarter of 2014.

Schedule_I_Summary_of_Investme

Schedule I. Summary of Investments - Other Than Investments in Related Parties	12 Months Ended
	Dec. 31, 2013
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, 2013
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)	2013			2012			2011
	Revenues
	Net investment income	$	1		$	1		$	1
	Net realized investment gains (losses)	4			4			(9		)
	Other income	—			9			40
	Total revenues	5			14			32
	Expenses
	Administrative and general	(7		)	1			3
	Interest	165			164			167
	Total expenses	158			165			170
	Loss from operations before income taxes and equity in net income of subsidiaries	(153		)	(151		)	(138		)
	Income tax benefit	22			144			46
	Loss before equity in net income of subsidiaries	(131		)	(7		)	(92		)
	Equity in net income of subsidiaries	1,068			635			704
	Net income	937			628			612
	Equity in other comprehensive income of subsidiaries	(389		)	351			143
	Total Comprehensive Income	$	548		$	979		$	755
	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)	2013			2012
	Assets
	Investment in subsidiaries	$	14,708		$	14,427
	Cash	1			—
	Fixed maturity securities available-for-sale, at fair value (amortized cost of $1 and $2)	1			2
	Short term investments	505			448
	Amounts due from subsidiaries	3			2
	Other assets	3			5
	Total assets	$	15,221		$	14,884
	Liabilities
	Short term debt	$	549		$	3
	Long term debt	1,981			2,527
	Other liabilities	40			40
	Total liabilities	2,570			2,570
	Stockholders' Equity
	Common stock ($2.50 par value; 500,000,000 shares authorized; 273,040,243 shares issued; 269,717,583 and 269,399,390 shares outstanding)	683			683
	Additional paid-in capital	2,145			2,146
	Retained earnings	9,495			8,774
	Accumulated other comprehensive income	442			831
	Treasury stock (3,322,660 and 3,640,853 shares), at cost	(91		)	(99		)
	Notes receivable for the issuance of common stock	(23		)	(21		)
	Total stockholders' equity	12,651			12,314
	Total liabilities and stockholders' equity	$	15,221		$	14,884
	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)	2013			2012			2011
	Cash Flows from Operating Activities
	Net income	$	937		$	628		$	612
	Adjustments to reconcile net income to net cash flows provided (used) by operating activities:
	Equity in net income of subsidiaries	(1,068		)	(635		)	(704		)
	Dividends received from subsidiaries	400			450			—
	Net realized investment (gains) losses	(4		)	(4		)	9
	Other, net	8			19			55
	Total adjustments	(664		)	(170		)	(640		)
	Net cash flows provided (used) by operating activities	$	273		$	458		$	(28	)
	Cash Flows from Investing Activities
Proceeds from fixed maturity securities	$	1		$	1		$	1
Change in short term investments	(57		)	(156		)	(77		)
Capital contributions to subsidiaries	(12		)	(399		)	(38		)
Return of capital from subsidiaries	—			—			6
Repayment of surplus note by subsidiary	—			250			250
Other, net	4			4			1
Net cash flows provided (used) by investing activities	$	(64	)	$	(300	)	$	143
Cash Flows from Financing Activities
Dividends paid to common stockholders	$	(216	)	$	(162	)	$	(108	)
Proceeds from the issuance of debt	—			—			396
Repayment of debt	(3		)	—			(409		)
Stock options exercised	2			1			5
Other, net	9			3			1
Net cash flows used by financing activities	$	(208	)	$	(158	)	$	(115	)
Net change in cash	$	1		$	—		$	—
Cash, beginning of year	—			—			—
Cash, end of year	$	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, 2013.
B. Commitments, Contingencies and Guarantees
In the course of selling business entities and assets to third parties, CNAF has agreed to indemnify purchasers for losses arising out of breaches of representation and warranties with respect to the business entities or assets being sold, including, in certain cases, losses arising from undisclosed liabilities or certain named litigation. Such indemnification agreements may include provisions that survive indefinitely. As of December 31, 2013, the aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third-party loans was $255 million.
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, 2013, 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. As of December 31, 2013, CNAF has no recorded liabilities related to indemnification agreements. The Parent Company does not believe that any indemnity claim payments are likely.
In the normal course of business, CNAF has provided guarantees to holders of structured settlement annuities (SSA) provided by certain of its subsidiaries, which expire through 2120. CNAF would be required to remit SSA payments due to claimants if the primary obligor failed to perform on these contracts. The potential amount of future payments that CNAF could be required to pay under these guarantees are approximately $2 billion at December 31, 2013. The Parent Company does not believe that a payable is likely under these guarantees.

Schedule_III_Supplementary_Ins

Schedule III. Supplementary Insurance Information	12 Months Ended
	Dec. 31, 2013
Supplementary Insurance Information [Abstract]	'
Schedule III. Supplementary Insurance Information	'
	SCHEDULE III. SUPPLEMENTARY INSURANCE INFORMATION
	Incorporated herein by reference to Note O to the Consolidated Financial Statements included under Item 8.

Schedule_IV_Reinsurance

Schedule IV. Reinsurance	12 Months Ended
	Dec. 31, 2013
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, 2013
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, 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
	Year ended December 31, 2011
	Deducted from assets:
	Allowance for doubtful accounts:
	Insurance and reinsurance receivables	$	285	$	(55	)	$	—		$	(27	)	$	203
	(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, 2013
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)	2013			2012			2011
	Deferred acquisition costs	$	624		$	598
	Reserves for unpaid claim and claim adjustment expenses	24,015			24,696
	Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.0% to 9.7%)	1,586			1,850
	Unearned premiums	3,718			3,610
	Net written premiums	7,348			6,964			$	6,798
	Net earned premiums	7,271			6,881			6,603
	Net investment income	2,240			2,074			1,845
	Incurred claim and claim adjustment expenses related to current year	5,113			5,266			4,901
	Incurred claim and claim adjustment expenses related to prior years	(115		)	(180		)	(429		)
	Amortization of deferred acquisition costs	1,362			1,274			1,176
	Paid claim and claim adjustment expenses	5,566			5,257			4,499

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	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.
Discontinued Operations	'
	The Company has historically reported certain run-off insurance operations acquired in its merger with The Continental Corporation in 1995 as discontinued operations. Due to the immateriality of the remaining liabilities, effective in the third quarter of 2011, the Company is no longer reporting these run-off operations as discontinued operations.
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 $1.3 billion as of December 31, 2013 and 2012. 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. Certain structured settlements are funded by annuities purchased from Continental Assurance Company (CAC) for which the related annuity obligations are reported in Future policy benefits reserves. 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 7.1% to 9.7% at December 31, 2013 and 2012. At December 31, 2013 and 2012, the discounted reserves for unfunded structured settlements were $580 million and $602 million, net of discount of $969 million and $1.0 billion.
	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 3.0% to 6.8% at December 31, 2013 and 3.0% to 6.5% at December 31, 2012. At December 31, 2013 and 2012, such discounted reserves totaled $2.4 billion and $2.2 billion, net of discount of $617 million and $837 million.
Future policy benefits reserves	'
	Future policy benefits reserves: Reserves for long term care products and payout annuity contracts are computed using the net level premium method, which incorporates actuarial assumptions as to morbidity, mortality, persistency, discount rate and expenses. Expense assumptions include the estimated effects of expenses to be incurred beyond the premium paying period. 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, 2013 and from 5.0% to 7.4% at December 31, 2012. Interest rates for payout annuity contracts range from 5.0% to 8.7% at December 31, 2013 and 2012. In 2012, the Company unlocked assumptions related to its payout annuity contracts due to anticipated adverse changes in discount rates, which reflected the then current low interest rate environment and our view of expected investment yields, resulting in loss recognition which increased insurance liabilities by $33 million.
Policyholders' funds reserves	'
	Policyholders' funds reserves: Policyholders' funds reserves primarily include 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, 2013 and 2012, the liability balances were $143 million. As of December 31, 2013 and 2012, included in Other assets on the Consolidated Balance Sheets were $1 million and $2 million of related assets for premium tax offsets. This asset is limited to the amount that is able to be offset against premium tax on future premium collections from business written or committed to be written.
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, 2013 and 2012, and $130 million and $125 million recorded as deposit liabilities at December 31, 2013 and 2012. 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.
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, 2013 and 2012, Deferred acquisition costs were presented net of Shadow Adjustments, as defined later in this note, of $342 million and $369 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 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 $88 million and $100 million at December 31, 2013 and 2012, 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.
	December 31, 2013	Number of Life Settlement Contracts	Fair Value of Life Settlement Contracts		Face Amount of Life Insurance Policies
			(In millions)		(In millions)
	Estimated maturity during:
	2014	60	$	13	$	39
	2015	60	11		35
	2016	50	9		32
	2017	50	8		29
	2018	40	7		26
	Thereafter	364	40		217
	Total	624	$	88	$	378
	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, 2013, 2012 and 2011 on contracts still being held was $(2) million, $11 million and $5 million. The gains recognized during the years ended December 31, 2013, 2012 and 2011 on contracts that settled were $15 million, $42 million and $28 million.
Separate Account Business	'
	Separate Account Business: Separate account assets and liabilities represent contract holder funds related to investment and annuity products for which the policyholder assumes substantially all the risk and reward. The assets are segregated into accounts with specific underlying investment objectives and are legally segregated from the Company. All assets of the separate account business are carried at fair value with an equal amount recorded for separate account liabilities. Fee income accruing to the Company related to separate accounts is primarily included within Other revenues on the Consolidated Statements of Operations.
	A number of separate account pension deposit contracts guarantee principal and an annual minimum rate of interest. If aggregate contract value in the separate account exceeds the fair value of the related assets, an additional Policyholders' funds liability is established. Certain of these contracts are subject to a fair value adjustment if terminated by the policyholder.
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, decreased $979 million and increased $789 million for the years ended December 31, 2013 and 2012. At December 31, 2013 and 2012, net unrealized gains on investments included in Accumulated other comprehensive income (AOCI) were correspondingly reduced by $532 million and $1,511 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 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 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. For asset-backed securities, 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.
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 Accumulated other comprehensive income. 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 of $2 million, $12 million and $4 million were included in determining net income (loss) for the years ended December 31, 2013, 2012 and 2011.
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 related to Hardy 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, 2013, 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
Intangible Assets	'
	Intangible Assets
	Intangible assets are reported within Other assets. Finite-lived intangible assets are amortized over their estimated useful lives. Indefinite-lived 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 attributable to the Company's common stockholders 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) attributable to CNA 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, 2013, 2012 and 2011, approximately 552 thousand, 417 thousand and 290 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 111 thousand, 730 thousand and 1.1 million 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, 2013
Accounting Policies [Abstract]	'
Life settlement contracts	'
	December 31, 2013	Number of Life Settlement Contracts	Fair Value of Life Settlement Contracts		Face Amount of Life Insurance Policies
			(In millions)		(In millions)
	Estimated maturity during:
	2014	60	$	13	$	39
	2015	60	11		35
	2016	50	9		32
	2017	50	8		29
	2018	40	7		26
	Thereafter	364	40		217
	Total	624	$	88	$	378

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2013
Investments [Abstract]	'
Net investment income	'
	Net Investment Income
	Years ended December 31
	(In millions)	2013			2012			2011
	Fixed maturity securities	$	1,998		$	2,022		$	2,011
	Short term investments	3			5			8
	Limited partnership investments	451			251			48
	Equity securities	12			12			20
	Mortgage loans	23			17			9
	Trading portfolio	17			24			9
	Other	2			7			7
	Gross investment income	2,506			2,338			2,112
	Investment expense	(56		)	(56		)	(58		)
	Net investment income	$	2,450		$	2,282		$	2,054
Net realized investment gains (losses)	'
	Net Realized Investment Gains (Losses)
	Years ended December 31
	(In millions)	2013			2012			2011
	Net realized investment gains (losses):
	Fixed maturity securities:
	Gross realized gains	$	201		$	232		$	289
	Gross realized losses	(146		)	(149		)	(311		)
	Net realized investment gains (losses) on fixed maturity securities	55			83			(22		)
	Equity securities:
	Gross realized gains	13			19			10
	Gross realized losses	(35		)	(42		)	(11		)
	Net realized investment gains (losses) on equity securities	(22		)	(23		)	(1		)
	Derivatives	(9		)	(2		)	—
	Short term investments and other	7			5			21
	Net realized investment gains (losses)	$	31		$	63		$	(2	)
Net change in unrealized gains (losses) on investments	'
	Net Change in Unrealized Gains
	Years ended December 31
	(In millions)	2013			2012			2011
	Net change in unrealized gains on investments:
	Fixed maturity securities	$	(2,541	)	$	1,871		$	1,442
	Equity securities	(15		)	5			(2		)
	Other	—			(1		)	(3		)
	Total net change in unrealized gains on investments	$	(2,556	)	$	1,875		$	1,437
Components of net other-than-temporary impairment losses recognized in earnings	'
	The components of OTTI losses recognized in earnings by asset type are summarized in the following table.
	Years ended December 31
	(In millions)	2013			2012			2011
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	22		$	27		$	95
	States, municipalities and political subdivisions	—			34			—
	Asset-backed:
	Residential mortgage-backed	19			50			105
	Other asset-backed	2			—			6
	Total asset-backed	21			50			111
	U.S. Treasury and obligations of government-sponsored enterprises	—			1			—
	Total fixed maturity securities available-for-sale	43			112			206
	Equity securities available-for-sale:
	Common stock	8			6			8
	Preferred stock	26			36			1
	Total equity securities available-for-sale	34			42			9
	Short term investments	1			—			1
	OTTI losses recognized in earnings	$	78		$	154		$	216
Summary of fixed maturity and equity securities	'
	Summary of Fixed Maturity and Equity Securities
	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
	December 31, 2012	Cost or			Gross			Gross			Estimated		Unrealized
		Amortized			Unrealized			Unrealized			Fair		OTTI
	(In millions)	Cost			Gains			Losses			Value		Losses (Gains)
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	19,530		$	2,698		$	21		$	22,207	$	—
	States, municipalities and political subdivisions	9,372			1,455			44			10,783		—
	Asset-backed:
	Residential mortgage-backed	5,745			246			71			5,920		(28		)
	Commercial mortgage-backed	1,692			147			17			1,822		(3		)
	Other asset-backed	929			23			—			952		—
	Total asset-backed	8,366			416			88			8,694		(31		)
	U.S. Treasury and obligations of government-sponsored enterprises	172			11			1			182		—
	Foreign government	588			25			—			613		—
	Redeemable preferred stock	113			13			1			125		—
	Total fixed maturity securities available-for-sale	38,141			4,618			155			42,604		$	(31	)
	Total fixed maturity securities trading	29			—			—			29
	Equity securities available-for-sale:
	Common stock	38			14			—			52
	Preferred stock	190			7			—			197
	Total equity securities available-for-sale	228			21			—			249
	Total	$	38,398		$	4,639		$	155		$	42,882
Securities in a gross unrealized loss position	'
	Securities in a Gross Unrealized Loss Position
		Less than 12 Months						12 Months or Longer					Total
	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
		Less than 12 Months						12 Months or Longer					Total
	December 31, 2012	Estimated			Gross			Estimated			Gross		Estimated			Gross
		Fair Value			Unrealized			Fair Value			Unrealized		Fair Value			Unrealized
	(In millions)				Losses						Losses					Losses
	Fixed maturity securities available-for-sale:
	Corporate and other bonds	$	846		$	13		$	108		$	8	$	954		$	21
	States, municipalities and political subdivisions	254			5			165			39		419			44
	Asset-backed:
	Residential mortgage-backed	583			5			452			66		1,035			71
	Commercial mortgage-backed	85			2			141			15		226			17
	Total asset-backed	668			7			593			81		1,261			88
	U.S. Treasury and obligations of government-sponsored enterprises	23			1			—			—		23			1
	Redeemable preferred stock	28			1			—			—		28			1
	Total	$	1,819		$	27		$	866		$	128	$	2,685		$	155
Activity related to the pretax fixed maturity credit loss component reflected within retained earnings for securities still held for which a portion of an OTTI loss was recognized in OCI	'
	The following table summarizes the activity for the years ended December 31, 2013, 2012 and 2011 related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held at December 31, 2013, 2012 and 2011 for which a portion of an OTTI loss was recognized in Other comprehensive income.
	Years ended December 31
	(In millions)	2013			2012			2011
	Beginning balance of credit losses on fixed maturity securities	$	95		$	92		$	141
	Additional credit losses for securities for which an OTTI loss was previously recognized	2			23			39
	Credit losses for securities for which an OTTI loss was not previously recognized	—			2			11
	Reductions for securities sold during the period	(23		)	(14		)	(67		)
	Reductions for securities the Company intends to sell or more likely than not will be required to sell	—			(8		)	(32		)
	Ending balance of credit losses on fixed maturity securities	$	74		$	95		$	92
Contractual maturity	'
	Contractual Maturity
		December 31, 2013						December 31, 2012
	(In millions)	Cost or			Estimated			Cost or			Estimated
		Amortized			Fair			Amortized			Fair
		Cost			Value			Cost			Value
	Due in one year or less	$	2,420		$	2,455		$	1,648		$	1,665
	Due after one year through five years	9,496			10,068			13,603			14,442
	Due after five years through ten years	11,667			11,954			8,726			9,555
	Due after ten years	15,692			16,720			14,164			16,942
	Total	$	39,275		$	41,197		$	38,141		$	42,604

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Summary of Derivative Instruments [Abstract]	'
Summary of aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments	'
	Derivative Financial Instruments
	December 31, 2013	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Equity warrants	$	5	$	—	$	—
	December 31, 2012	Contractual/		Estimated Fair Value
		Notional
	(In millions)	Amount		Asset		(Liability)
	Without hedge designation
	Credit default swaps - purchased protection	$	20	$	—	$	(1	)
	Currency forwards	59		—		(2		)
	Equity warrants	5		—		—
	Total	$	84	$	—	$	(3	)

Fair_Value_Tables

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Assets and liabilities measured at fair value on a recurring basis	'
	Assets and liabilities measured at fair value on a recurring basis are summarized below.
	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
	Liabilities
	Derivative financial instruments, included in Other liabilities	$	—	$	—		$	—		$	—
	Total liabilities	$	—	$	—		$	—		$	—
	December 31, 2012									Total
										Assets/(Liabilities)
	(In millions)	Level 1		Level 2			Level 3			at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds	$	6	$	22,011		$	219		$	22,236
	States, municipalities and political subdivisions	—		10,687			96			10,783
	Asset-backed:
	Residential mortgage-backed	—		5,507			413			5,920
	Commercial mortgage-backed	—		1,693			129			1,822
	Other asset-backed	—		584			368			952
	Total asset-backed	—		7,784			910			8,694
	U.S. Treasury and obligations of government-sponsored enterprises	158		24			—			182
	Foreign government	140		473			—			613
	Redeemable preferred stock	40		59			26			125
	Total fixed maturity securities	344		41,038			1,251			42,633
	Equity securities	117		98			34			249
	Other invested assets	—		58			1			59
	Short term investments	987		799			6			1,792
	Life settlement contracts, included in Other assets	—		—			100			100
	Separate account business	4		306			2			312
	Total assets	$	1,452	$	42,299		$	1,394		$	45,145
	Liabilities
	Derivative financial instruments, included in Other liabilities	$	—	$	(2	)	$	(1	)	$	(3	)
	Total liabilities	$	—	$	(2	)	$	(1	)	$	(3	)
Table of reconciliation for assets and liablities measured at fair value on a recurring basis using significant unobservable inputs	'
	The tables below present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the years ended December 31, 2013 and 2012.
	Level 3	Balance at		Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)*			Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)			Purchases			Sales			Settlements			Transfers into		Transfers out			Balance at		Unrealized gains (losses) on Level 3 assets and liabilities held at 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	)
	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, 2012 recognized in net income (loss)*
	(In millions)	January 1,																	Level 3		of Level 3			December 31,
		2012																						2012
	Fixed maturity securities:
	Corporate and other bonds	$	482	$	6		$	4		$	231		$	(136	)	$	(88	)	$	45	$	(325	)	$	219	$	(3	)
	States, municipalities and political subdivisions	171		—			—			14			—			(89		)	—		—			96		—
	Asset-backed:
	Residential mortgage-backed	452		(14		)	2			97			—			(40		)	—		(84		)	413		(18		)
	Commercial mortgage-backed	59		8			14			165			(12		)	(28		)	13		(90		)	129		—
	Other asset-backed	343		11			8			615			(365		)	(128		)	—		(116		)	368		—
	Total asset-backed	854		5			24			877			(377		)	(196		)	13		(290		)	910		(18		)
	Redeemable preferred stock	—		—			(1		)	53			(26		)	—			—		—			26		—
	Total fixed maturity securities	1,507		11			27			1,175			(539		)	(373		)	58		(615		)	1,251		(21		)
	Equity securities	67		(36		)	6			27			(16		)	—			—		(14		)	34		(38		)
	Other invested assets, including derivatives, net	10		—			—			—			—			(10		)	—		—			—		—
	Short term investments	27		—			—			23			(4		)	(41		)	1		—			6		—
	Life settlement contracts	117		53			—			—			—			(70		)	—		—			100		11
	Separate account business	23		—			—			—			(21		)	—			—		—			2		—
	Total	$	1,751	$	28		$	33		$	1,225		$	(580	)	$	(494	)	$	59	$	(629	)	$	1,393	$	(48	)
Quantitative information about significant unobservable inputs in the fair value measurement of level 3 assets	'
	The table below presents quantitative information about the significant unobservable inputs utilized by the Company in the fair value measurements of Level 3 assets. Valuations for assets and liabilities not presented in the table below are primarily based on broker/dealer quotes for which there is a lack of transparency as to inputs used to develop the valuations. The quantitative detail of these unobservable inputs is neither provided nor reasonably available to the Company.
	Assets	Fair Value at December 31, 2013		Valuation Technique(s)		Unobservable Input(s)	Range
	(In millions)						(Weighted Average)
	Fixed maturity securities	$	142	Discounted cash flow		Credit spread	1.74% - 19.90% (3.98%)
	Equity securities	$	10	Market approach		Private offering price	$360.12 - $4,267.66 per share ($1,147.95)
	Life settlement contracts	$	88	Discounted cash flow		Discount rate risk premium	9%
						Mortality assumption	70% - 743% (191.6%)
	Assets	Fair Value at December 31, 2012		Valuation Technique(s)		Unobservable Input(s)	Range
	(In millions)						(Weighted Average)
	Fixed maturity securities	$	121	Discounted cash flow		Expected call date	3.3 - 5.3 years (4.3 years)
						Credit spread adjustment	0.02% - 0.48% (0.17%)
		$	72	Market approach		Private offering price	$42.39 - $102.32 ($100.11)
	Equity securities	$	34	Market approach		Private offering price	$4.54 - $3,842.00 per share
							($571.17 per share)
	Life settlement contracts	$	100	Discounted cash flow		Discount rate risk premium	9%
						Mortality assumption	69% - 883% (208.9%)
Carrying amount and estimated fair value of financial instrument assets and liabilities not measured at fair value	'
	The carrying amount and estimated fair value of the Company's financial instrument assets and liabilities which are not measured at fair value on the Consolidated Balance Sheets are listed in the tables below.
	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
	31-Dec-12	Carrying		Estimated Fair Value
	(In millions)	Amount		Level 1			Level 2			Level 3			Total
	Financial assets
	Notes receivable for the issuance of common stock	$	21	$	—		$	—		$	21		$	21
	Mortgage loans	401		—			—			418			418
	Financial liabilities
	Premium deposits and annuity contracts	$	100	$	—		$	—		$	104		$	104
	Short term debt	13		—			13			—			13
	Long term debt	2,557		—			3,016			—			3,016

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
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)	2013			2012			2011
	Income tax expense at statutory rates	$	(460	)	$	(305	)	$	(305	)
	Tax benefit from tax exempt income	97			84			74
	Foreign taxes and credits	(1		)	(13		)	(3		)
	Taxes related to domestic affiliate	—			—			(21		)
	Prior year tax adjustment	—			—			20
	Other tax expense	(12		)	(10		)	(7		)
	Income tax expense	$	(376	)	$	(244	)	$	(242	)
Current and deferred components of the Company's income tax (expense) benefit	'
	Current and Deferred Taxes
	Years ended December 31
	(In millions)	2013			2012			2011
	Current tax expense	$	(299	)	$	(97	)	$	(54	)
	Deferred tax expense	(77		)	(147		)	(188		)
	Total income tax expense	$	(376	)	$	(244	)	$	(242	)
Significant components of the Company's deferred tax assets and liabilities	'
	Components of Net Deferred Tax Asset
	31-Dec
	(In millions)	2013			2012
	Deferred Tax Assets:
	Insurance reserves:
	Property and casualty claim and claim adjustment expense reserves	$	289		$	352
	Unearned premium reserves	178			162
	Receivables	50			60
	Employee benefits	187			384
	Life settlement contracts	46			45
	Deferred retroactive reinsurance benefit	66			—
	Other assets	149			160
	Gross deferred tax assets	965			1,163
	Deferred Tax Liabilities:
	Investment valuation differences	68			38
	Deferred acquisition costs	232			238
	Net unrealized gains	383			737
	Other liabilities	62			57
	Gross deferred tax liabilities	745			1,070
	Net deferred tax asset	$	220		$	93

Claim_and_Claim_Adjustment_Exp1

Claim and Claim Adjustment Expense Reserves (Tables)	12 Months Ended
	Dec. 31, 2013
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)	2013			2012			2011
	Reserves, beginning of year:
	Gross	$	24,763		$	24,303		$	25,496
	Ceded	5,126			5,020			6,122
	Net reserves, beginning of year	19,637			19,283			19,374
	Change in net reserves due to acquisition (disposition) of subsidiaries	—			291			(277		)
	Net incurred claim and claim adjustment expenses:
	Provision for insured events of current year	5,114			5,273			4,904
	Decrease in provision for insured events of prior years	(115		)	(182		)	(429		)
	Amortization of discount	154			145			135
	Total net incurred (a)	5,153			5,236			4,610
	Net payments attributable to:
	Current year events	(981		)	(988		)	(1,029		)
	Prior year events	(4,588		)	(4,280		)	(3,473		)
	Total net payments	(5,569		)	(5,268		)	(4,502		)
	Foreign currency translation adjustment and other	(104		)	95			78
	Net reserves, end of year	19,117			19,637			19,283
	Ceded reserves, end of year	4,972			5,126			5,020
	Gross reserves, end of year	$	24,089		$	24,763		$	24,303
	(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)	2013			2012			2011
	Property and casualty reserve development	$	(115	)	$	(180	)	$	(429	)
	Life reserve development in life company	—			(2		)	—
	Total	$	(115	)	$	(182	)	$	(429	)
Gross and net carried claim and claim adjustment expense reserves	'
	Gross and Net Carried Claim and Claim Adjustment Expense Reserves
	December 31, 2013	CNA Specialty			CNA Commercial			Hardy			Life &			Corporate			Total
	(In millions)										Group Non-Core			& Other Non-Core
	Gross Case Reserves	$	2,270		$	5,829		$	275		$	2,748		$	1,140		$	12,262
	Gross IBNR Reserves	4,419			4,820			111			310			2,167			11,827
	Total Gross Carried Claim and Claim Adjustment Expense Reserves	$	6,689		$	10,649		$	386		$	3,058		$	3,307		$	24,089
	Net Case Reserves	$	2,024		$	5,358		$	159		$	2,352		$	283		$	10,176
	Net IBNR Reserves	4,142			4,269			75			271			184			8,941
	Total Net Carried Claim and Claim Adjustment Expense Reserves	$	6,166		$	9,627		$	234		$	2,623		$	467		$	19,117
	December 31, 2012	CNA Specialty			CNA Commercial			Hardy			Life &			Corporate			Total
	(In millions)										Group Non-Core			& Other Non-Core
	Gross Case Reserves	$	2,292		$	6,146		$	333		$	2,690		$	1,207		$	12,668
	Gross IBNR Reserves	4,456			5,180			188			316			1,955			12,095
	Total Gross Carried Claim and Claim Adjustment Expense Reserves	$	6,748		$	11,326		$	521		$	3,006		$	3,162		$	24,763
	Net Case Reserves	$	2,008		$	5,611		$	192		$	2,253		$	292		$	10,356
	Net IBNR Reserves	4,104			4,600			82			275			220			9,281
	Total Net Carried Claim and Claim Adjustment Expense Reserves	$	6,112		$	10,211		$	274		$	2,528		$	512		$	19,637
Net prior year development	'
	Net Prior Year Development
	Year ended December 31, 2013
	(In millions)	CNA			CNA Commercial			Hardy			Corporate			Total
		Specialty									& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(230	)	$	104		$	14		$	(6	)	$	(118	)
	Pretax (favorable) unfavorable premium development	(17		)	(9		)	(17		)	1			(42		)
	Total pretax (favorable) unfavorable net prior year development	$	(247	)	$	95		$	(3	)	$	(5	)	$	(160	)
	Year ended December 31, 2012
	(In millions)	CNA			CNA Commercial			Hardy			Corporate			Total
		Specialty									& Other
											Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(135	)	$	(46	)	$	(11	)	$	(13	)	$	(205	)
	Pretax (favorable) unfavorable premium development	(15		)	(35		)	3			1			(46		)
	Total pretax (favorable) unfavorable net prior year development	$	(150	)	$	(81	)	$	(8	)	$	(12	)	$	(251	)
	Year ended December 31, 2011
	(In millions)	CNA			CNA Commercial			Corporate			Total
		Specialty						& Other
								Non-Core
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(217	)	$	(204	)	$	(2	)	$	(423	)
	Pretax (favorable) unfavorable premium development	(28		)	21			(1		)	(8		)
	Total pretax (favorable) unfavorable net prior year development	$	(245	)	$	(183	)	$	(3	)	$	(431	)
Net prior year claim and allocated claim adjustment expense reserve development for CNA Specialty segment	'
	The following table provides further detail of the net prior year claim and allocated claim adjustment expense reserve development (development) recorded for the CNA Specialty segment for the years ended December 31, 2013, 2012 and 2011.
	Years ended December 31
	(In millions)	2013			2012			2011
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Medical Professional Liability	$	(35	)	$	(32	)	$	(92	)
	Other Professional Liability and Management Liability	(101		)	(22		)	(78		)
	Surety	(74		)	(63		)	(47		)
	Warranty	(3		)	(5		)	(13		)
	Other	(17		)	(13		)	13
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	(230	)	$	(135	)	$	(217	)
Net prior year claim and allocated claim adjustment expense reserve development for CNA Commercial segment	'
	The following table provides further detail of the development recorded for the CNA Commercial segment for the years ended December 31, 2013, 2012 and 2011.
	Years ended December 31
	(In millions)	2013			2012			2011
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Commercial Auto	$	15		$	27		$	(98	)
	General Liability	59			(64		)	(39		)
	Workers' Compensation	92			15			36
	Property and Other	(62		)	(24		)	(103		)
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	104		$	(46	)	$	(204	)
Net prior year claim and allocated claim adjustment expense reserve development for Hardy segment	'
	The following table provides further detail of the development recorded for the Hardy segment for the years ended December 31, 2013 and 2012.
	Years ended December 31
	(In millions)	2013			2012
	Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development:
	Marine and Aviation	$	2		$	—
	Non-Marine Property	12			(7		)
	Property Treaty	(5		)	(3		)
	Specialty	(6		)	(1		)
	Commutation	11			—
	Total pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$	14		$	(11	)
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)	2013			2012			2011
	Net A&EP adverse development before consideration of LPT	$	363		$	261		$	84
	Provision for uncollectible third-party reinsurance on A&EP	140			—			—
	Additional amounts ceded under LPT	503			261			84
	Retroactive reinsurance benefit recognized	(314		)	(261		)	(84		)
	Pretax impact of unrecognized deferred retroactive reinsurance benefit	$	189		$	—		$	—

Reinsurance_Tables

Reinsurance (Tables)	12 Months Ended
	Dec. 31, 2013
Reinsurance Disclosures [Abstract]	'
Components of Reinsurance Receivables	'
	The following table summarizes the amounts receivable from reinsurers at December 31, 2013 and 2012.
	Components of Reinsurance Receivables
	31-Dec
	(In millions)	2013			2012
	Reinsurance receivables related to insurance reserves:
	Ceded claim and claim adjustment expenses	$	4,972		$	5,126
	Ceded future policy benefits	733			759
	Ceded policyholders' funds	35			35
	Reinsurance receivables related to paid losses	348			311
	Reinsurance receivables	6,088			6,231
	Allowance for uncollectible reinsurance	(71		)	(73		)
	Reinsurance receivables, net of allowance for uncollectible reinsurance	$	6,017		$	6,158
Components of Earned and Written Premiums	'
	The effects of reinsurance on earned premiums and written premiums for the years ended December 31, 2013, 2012 and 2011 are shown in the following tables.
	Components of Earned Premiums
	(In millions)	Direct			Assumed			Ceded		Net		Assumed/
												Net %
	2013 Earned Premiums
	Property and casualty	$	9,063		$	258		$	2,609	$	6,712	3.8	%
	Accident and health	512			48			1		559		8.6	%
	Life	49			—			49		—		—
	Total earned premiums	$	9,624		$	306		$	2,659	$	7,271	4.2	%
	2012 Earned Premiums
	Property and casualty	$	8,354		$	197		$	2,229	$	6,322	3.1	%
	Accident and health	514			47			1		560		8.4	%
	Life	51			—			51		—		—
	Total earned premiums	$	8,919		$	244		$	2,281	$	6,882	3.5	%
	2011 Earned Premiums
	Property and casualty	$	7,858		$	95		$	1,919	$	6,034	1.6	%
	Accident and health	521			50			2		569		8.8	%
	Life	55			—			55		—		—
	Total earned premiums	$	8,434		$	145		$	1,976	$	6,603	2.2	%
	Components of Written Premiums
	(In millions)	Direct			Assumed			Ceded		Net		Assumed/
												Net %
	2013 Written Premiums
	Property and casualty	$	9,103		$	249		$	2,556	$	6,796	3.7	%
	Accident and health	506			47			1		552		8.5	%
	Life	49			—			49		—		—
	Total written premiums	$	9,658		$	296		$	2,606	$	7,348	4	%
	2012 Written Premiums
	Property and casualty	$	8,467		$	169		$	2,225	$	6,411	2.6	%
	Accident and health	507			47			1		553		8.5	%
	Life	51			—			51		—		—
	Total written premiums	$	9,025		$	216		$	2,277	$	6,964	3.1	%
	2011 Written Premiums
	Property and casualty	$	7,976		$	102		$	1,857	$	6,221	1.6	%
	Accident and health	529			50			2		577		8.7	%
	Life	55			—			55		—		—
	Total written premiums	$	8,560		$	152		$	1,914	$	6,798	2.2	%
Components of Life Insurance Inforce	'
	Components of Life Insurance Inforce
	(In millions)	Direct			Assumed			Ceded		Net
	2013	$	5,127		$	—		$	5,118	$	9
	2012	5,713			—			5,702		11
	2011	6,528			—			6,515		13

Debt_Tables

Debt (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Schedule of debt instruments	'
	Debt
	31-Dec
	(In millions)	2013			2012
	Short term debt:
	Senior notes of CNAF, 5.850%, face amount of $549, due December 15, 2014	$	549		$	—
	Other debt	—			13
	Total short term debt	549			13
	Long term debt:
	Senior notes of CNAF:
	5.850%, face amount of $549, due December 15, 2014	—			548
	6.500%, face amount of $350, due August 15, 2016	349			348
	6.950%, face amount of $150, due January 15, 2018	149			149
	7.350%, face amount of $350, due November 15, 2019	348			348
	5.875%, face amount of $500, due August 15, 2020	497			496
	5.750%, face amount of $400, due August 15, 2021	397			397
	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	2,011			2,557
	Total debt	$	2,560		$	2,570
Maturity of debt	'
	Maturity of Debt
	(In millions)
	2014	$	549
	2015	—
	2016	350
	2017	—
	2018	150
	Thereafter	1,523
	Less discount	(12		)
	Total	$	2,560

Benefit_Plans_Tables

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
Funded status	'
	The following table provides a reconciliation of benefit obligations and plan assets for the years ended December 31, 2013 and 2012.
	Funded Status
		Pension Benefits								Postretirement Benefits
	(In millions)	2013				2012				2013			2012
	Benefit obligation at January 1	$	3,271			$	3,003			$	47		$	49
	Changes in benefit obligation:
	Service cost	12				12				1			—
	Interest cost	121				135				1			2
	Participants' contributions	—				—				5			5
	Actuarial (gain) loss	(289		)		266				(3		)	3
	Benefits paid	(165		)		(164		)		(12		)	(12		)
	Settlements	(8		)		—				—			—
	Foreign currency translation and other	1				19				1			—
	Benefit obligation at December 31	2,943				3,271				40			47
	Fair value of plan assets at January 1	2,425				2,212				—			—
	Change in plan assets:
	Actual return on plan assets	311				245				—			—
	Company contributions	92				115				7			7
	Participants' contributions	—				—				5			5
	Benefits paid	(165		)		(164		)		(12		)	(12		)
	Settlements	(8		)		—				—			—
	Foreign currency translation and other	1				17				—			—
	Fair value of plan assets at December 31	2,656				2,425				—			—
	Funded status	$	(287	)		$	(846	)		$	(40	)	$	(47	)
	Amounts recognized on the Consolidated Balance Sheets at December 31:
	Other assets	$	9			$	—			$	—		$	—
	Other liabilities	(296		)		(846		)		(40		)	(47		)
	Net amount recognized	$	(287	)		$	(846	)		$	(40	)	$	(47	)
	Amounts recognized in Accumulated other comprehensive income, not yet recognized in net periodic cost (benefit):
	Prior service credit	$	—			$	—			$	(98	)	$	(116	)
	Net actuarial loss	745				1,213				8			11
	Net amount recognized	$	745			$	1,213			$	(90	)	$	(105	)
Components of net periodic cost (benefit)	'
	Net Periodic Cost (Benefit)
	Years ended December 31
	(In millions)	2013				2012				2011
	Pension cost (benefit)
	Service cost	$	12			$	12			$	13
	Interest cost on projected benefit obligation	121				135				146
	Expected return on plan assets	(181		)		(171		)		(172		)
	Amortization of net actuarial (gain) loss	47				39				25
	Settlement loss	3				—				—
	Net periodic pension cost (benefit)	$	2			$	15			$	12
	Postretirement cost (benefit)
	Service cost	$	1			$	—			$	1
	Interest cost on projected benefit obligation	1				2				3
	Amortization of prior service credit	(18		)		(18		)		(19		)
	Amortization of net actuarial (gain) loss	2				1				—
	Net periodic postretirement cost (benefit)	$	(14	)		$	(15	)		$	(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)	2013				2012				2011
	Pension and postretirement benefits
	Amounts arising during the period	$	422			$	(195	)		$	(325	)
	Reclassification adjustment relating to prior service credit	(18		)		(18		)		(19		)
	Reclassification adjustment relating to actuarial loss	49				40				25
	Total increase (decrease) in Other comprehensive income	$	453			$	(173	)		$	(319	)
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 Accumulated other comprehensive income into net periodic cost (benefit) during 2014.
	(In millions)		Pension				Postretirement Benefits
			Benefits
	Amortization of prior service credit		$	—			$	(18	)
	Amortization of net actuarial loss		25				—
	Total estimated amounts to be recognized		$	25			$	(18	)
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	2013			2012
	Pension benefits
	Discount rate	4.65	%		3.8	%
	Expected long term rate of return	7.5			7.75
	Rate of compensation increases	3.99			4.066
	Postretirement benefits
	Discount rate	3.6	%		2.8	%
	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	2013			2012			2011
	Pension benefits
	Discount rate	3.8	%		4.6	%		5.375	%
	Expected long term rate of return	7.75			8			8
	Rate of compensation increases	4.066			4.125			5.03
	Postretirement benefits
	Discount rate	2.8	%		3.75	%		4.375	%
Fair value of plan assets measured on a recurring basis	'
	Pension plan assets measured at fair value on a recurring basis are summarized below.
	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
	December 31, 2012
	(In millions)		Level 1				Level 2				Level 3			Total Assets
														at Fair Value
	Assets
	Fixed maturity securities:
	Corporate and other bonds		$	—			$	436			$	11		$	447
	States, municipalities and political subdivisions		—				91				—			91
	Asset-backed:
	Residential mortgage-backed		—				161				—			161
	Commercial mortgage-backed		—				105				—			105
	Total asset-backed		—				266				—			266
	Total fixed maturity securities		—				793				11			804
	Equity securities		386				102				5			493
	Derivative financial instruments		1				—				—			1
	Short term investments		37				82				—			119
	Limited partnerships:
	Hedge funds		—				537				359			896
	Private equity		—				—				62			62
	Total limited partnerships		—				537				421			958
	Other assets		—				40				—			40
	Investment contracts with insurance company		—				—				10			10
	Total assets		$	424			$	1,554			$	447		$	2,425
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, 2013 and 2012.
	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
	Level 3	Balance at January 1, 2012				Actual return on assets still held at December 31, 2012				Actual return on assets sold during the year ended December 31, 2012			Purchases, sales, and settlements			Net transfers into (out of) Level 3			Balance at December 31, 2012
	(In millions)
	Fixed maturity securities:
	Corporate and other bonds	$	10			$	1			$	—		$	—		$	—		$	11
	Equity securities	5				—				—			—			—			5
	Limited partnerships:
	Hedge funds	330				41				3			(15		)	—			359
	Private equity	65				8				—			(11		)	—			62
	Total limited partnerships	395				49				3			(26		)	—			421
	Investment contracts with insurance company	10				—				—			—			—			10
	Total	$	420			$	50			$	3		$	(26	)	$	—		$	447
Estimated future minimum benefit payments to participants	'
	Estimated Future Minimum Benefit Payments to Participants
	(In millions)	Pension Benefits				Postretirement Benefits
	2014	$	189			$	5
	2015	191				4
	2016	194				5
	2017	199				4
	2018	203				4
	2019-2023	1,013				14
Significant assumptions used to estimate fair value of stock options and SARS	'
	The following table presents the significant assumptions used to estimate the fair value of granted stock options and SARs for the years ended December 31, 2012 and 2011.
	Years ended December 31	2012			2011
	Weighted average expected life of the securities granted (in years)	5.68			5.61
	Estimate of the underlying common stock's volatility	40.39	%		39.88	%
	Expected dividend yield	2.1	%		1.5	%
	Risk free interest rate	1	%		2.2	%
Stock option and SARS activity	'
	The following table presents activity for stock options and SARs under the Plan in 2013.
			Number of Awards			Weighted-Average Exercise Price per Award				Aggregate Intrinsic Value			Weighted-Average Remaining Contractual Term (in years)
	Outstanding at January 1, 2013		1,158,700			$	25.93
	Awards granted		—			—
	Awards exercised		(117,950	)		21.19
	Awards forfeited, canceled or expired		(4,100	)		30.66
	Outstanding at December 31, 2013		1,036,650			$	26.45			$	17	million	4.16
	Outstanding, fully vested and expected to vest		1,032,849			$	26.45			$	17	million	4.15
	Outstanding, exercisable		936,650			$	26.42			$	15	million	3.87
Weighted-average grant date fair value for awards granted, total intrinsic value for awards exercised and total fair value for awards vested	'
	The following table presents weighted-average grant date fair value for awards granted, total intrinsic value for awards exercised and total fair value for awards vested for the years ended December 31, 2013, 2012 and 2011.
	Years ended December 31	2013				2012				2011
	Weighted-average grant date fair value					$	8.81			$	9.38
	Total intrinsic value of awards exercised	$	1,495	thousand		$	548	thousand		$	481	thousand
	Fair value of awards vested	$	1	million		$	1	million		$	2	million
Restricted shares, performance-based restricted stock units and performance share unit activity	'
	The following table presents activity for restricted shares, performance-based RSUs and performance share units under the Plan in 2013.
		Number of Awards			Weighted-Average Grant Date Fair Value
	Balance at January 1, 2013	882,321			$	26.15
	Awards granted	351,364			31.8
	Awards vested	(417,955	)		24.04
	Awards forfeited, canceled or expired	(13,770	)		28.72
	Performance-based adjustment	45,714			28.39
	Balance at December 31, 2013	847,674			$	29.61

Other_Intangible_Assets_Tables

Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Intangible Assets, Gross (Excluding Goodwill) [Abstract]	'
Schedule of Other Intangible Assets	'
	Other intangible assets are presented in the following table.
			31-Dec-13				31-Dec-12
	(In millions)	Economic Useful Life	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
	Finite-lived intangible assets:
	Value of business acquired	1 - 4 years	$	64	$	63	$	62	$	43
	Trade name	8 years	8		2		8		—
	Distribution channel	15 years	13		1		13		—
	Total finite-lived intangible assets		85		66		83		43
	Indefinite-lived intangible assets:
	Syndicate capacity		58				57
	Agency force		16				16
	Total indefinite-lived intangible assets		74				73
	Total other intangible assets		$	159	$	66	$	156	$	43

Operating_Leases_Commitments_a1

Operating Leases, Commitments and Contingencies, and Guarantees (Tables)	12 Months Ended
	Dec. 31, 2013
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
	2014	$	37	$	2
	2015	32		—
	2016	29		—
	2017	23		—
	2018	17		—
	Thereafter	70		—
	Total	$	208	$	2

Stockholders_Equity_and_Statut1

Stockholders' Equity and Statutory Accounting Practices (Tables)	12 Months Ended
	Dec. 31, 2013
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)	2013 (b)		2012		2013 (b)		2012		2011
	Combined Continental Casualty Companies (a)	$	11,137	$	9,998	$	913	$	391	$	954
	Life company	597		556		48		44		29
	________________
	(a)	Represents the combined statutory surplus of CCC and its subsidiaries, including the life company.
	(b)	Information derived from the statutory-basis financial statements to be filed with insurance regulators.

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) by Component (Tables)	12 Months Ended
	Dec. 31, 2013
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 year ended December 31, 2013.
		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 of $0, $(10), $11, $0, and $1	—			21			(20		)	—			1
	Other comprehensive income (loss) after tax of $(3), $364, $(158), $0, and $203	6			(679		)	295			(11		)	(389		)
	Balance at December 31, 2013	$	26		$	692		$	(426	)	$	150		$	442
	The following table displays the components of AOCI included on the Consolidated Balance Sheet for the year ended December 31, 2012.
	31-Dec	2012
	(In millions)	Tax			After-tax
	Cumulative foreign currency translation adjustment	$	—		$	161
	Pension and postretirement benefits	387			(721		)
	Net unrealized gains (losses) on investments with OTTI losses	(11		)	20
	Net unrealized gains (losses) on other investments	(721		)	1,371
	Accumulated other comprehensive income (loss)	$	(345	)	$	831

Business_Segments_Tables

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Significant components of the Company's continuing operations and selected balance sheet items	'
	Year ended December 31, 2013	CNA			CNA			Hardy			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Net written premiums (a)	$	3,091		$	3,312		$	396		$	552		$	(1	)	$	(2	)	$	7,348
	Operating revenues
	Net earned premiums	$	3,004		$	3,350		$	361		$	559		$	(1	)	$	(2	)	$	7,271
	Net investment income	657			927			4			830			32			—			2,450
	Other revenues	257			96			—			(2		)	12			(2		)	361
	Total operating revenues	3,918			4,373			365			1,387			43			(4		)	10,082
	Claims, Benefits and Expenses
	Net incurred claims and benefits	1,704			2,475			162			1,395			191			—			5,927
	Policyholders’ dividends	6			7			—			7			—			—			20
	Amortization of deferred acquisition costs	628			600			106			28			—			—			1,362
	Other insurance related expenses	272			547			69			134			(3		)	(2		)	1,017
	Other expenses	236			26			19			12			183			(2		)	474
	Total claims, benefits and expenses	2,846			3,655			356			1,576			371			(4		)	8,800
	Operating income (loss) from continuing operations before income tax	1,072			718			9			(189		)	(328		)	—			1,282
	Income tax (expense) benefit on operating income (loss)	(365		)	(250		)	1			131			118			—			(365		)
	Net operating income (loss) from continuing operations attributable to CNA	707			468			10			(58		)	(210		)	—			917
	Net realized investment gains (losses), pretax	(3		)	(13		)	1			37			9			—			31
	Income tax (expense) benefit on net realized investment gains (losses)	1			4			—			(13		)	(3		)	—			(11		)
	Net realized investment gains (losses)	(2		)	(9		)	1			24			6			—			20
	Net income (loss) from continuing operations attributable to CNA	$	705		$	459		$	11		$	(34	)	$	(204	)	$	—		$	937
	____________________
	(a)	Related to business in property and casualty companies only.
	December 31, 2013
	(In millions)
	Reinsurance receivables	$	546		$	1,075		$	197		$	1,203		$	3,067		$	—		$	6,088
	Insurance receivables	$	775		$	1,099		$	176		$	11		$	2		$	—		$	2,063
	Deferred acquisition costs	$	318		$	257		$	49		$	—		$	—		$	—		$	624
	Goodwill	$	117		$	—		$	38		$	—		$	—		$	—		$	155
	Insurance reserves
	Claim and claim adjustment expenses	$	6,689		$	10,649		$	386		$	3,058		$	3,307		$	—		$	24,089
	Unearned premiums	1,805			1,536			249			128			—			—			3,718
	Future policy benefits	—			—			—			10,471			—			—			10,471
	Policyholders’ funds	9			15			—			92			—			—			116
	Year ended December 31, 2012	CNA			CNA			Hardy(b)			Life &			Corporate
		Specialty			Commercial						Group			& Other
	(In millions)										Non-Core			Non-Core			Eliminations			Total
	Net written premiums (a)	$	2,924		$	3,373		$	117		$	553		$	(1	)	$	(2	)	$	6,964
	Operating revenues
	Net earned premiums	$	2,898		$	3,306		$	120		$	560		$	—		$	(2	)	$	6,882
	Net investment income	592			854			3			801			32			—			2,282
	Other revenues	230			40			1			34			16			(1		)	320
	Total operating revenues	3,720			4,200			124			1,395			48			(3		)	9,484
	Claims, Benefits and Expenses
	Net incurred claims and benefits	1,831			2,574			72			1,406			(16		)	—			5,867
	Policyholders’ dividends	2			11			—			16			—			—			29
	Amortization of deferred acquisition costs	614			588			44			28			—			—			1,274
	Other insurance related expenses	301			578			25			144			3			(2		)	1,049
	Other expenses	206			36			9			23			183			(1		)	456
	Total claims, benefits and expenses	2,954			3,787			150			1,617			170			(3		)	8,675
	Operating income (loss) from continuing operations before income tax	766			413			(26		)	(222		)	(122		)	—			809
	Income tax (expense) benefit on operating income (loss)	(262		)	(136		)	3			132			41			—			(222		)
	Net operating income (loss) from continuing operations attributable to CNA	504			277			(23		)	(90		)	(81		)	—			587
	Net realized investment gains (losses), pretax	22			38			(1		)	—			4			—			63
	Income tax (expense) benefit on net realized investment gains (losses)	(9		)	(11		)	—			—			(2		)	—			(22		)
	Net realized investment gains (losses)	13			27			(1		)	—			2			—			41
	Net income (loss) from continuing operations attributable to CNA	$	517		$	304		$	(24	)	$	(90	)	$	(79	)	$	—		$	628
	____________________
	(a)	Related to business in property and casualty companies only.
	(b)	Included from date of acquisition.
	December 31, 2012
(In millions)
Reinsurance receivables	$	665		$	1,155		$	294		$	1,273		$	2,844		$	—		$	6,231
Insurance receivables	$	673		$	1,116		$	181		$	9		$	4		$	—		$	1,983
Deferred acquisition costs	$	300		$	269		$	29		$	—		$	—		$	—		$	598
Goodwill	$	117		$	—		$	37		$	—		$	—		$	—		$	154
Insurance reserves
Claim and claim adjustment expenses	$	6,748		$	11,326		$	521		$	3,006		$	3,162		$	—		$	24,763
Unearned premiums	1,685			1,569			222			134			—			—			3,610
Future policy benefits	—			—			—			11,475			—			—			11,475
Policyholders’ funds	8			15			—			134			—			—			157
Year ended December 31, 2011	CNA			CNA			Life &			Corporate
	Specialty			Commercial			Group			& Other
(In millions)							Non-Core			Non-Core			Eliminations			Total
Net written premiums (a)	$	2,872		$	3,350		$	577		$	2		$	(3	)	$	6,798
Operating revenues
Net earned premiums	$	2,796		$	3,240		$	569		$	1		$	(3	)	$	6,603
Net investment income	500			763			759			32			—			2,054
Other revenues	221			54			13			6			—			294
Total operating revenues	3,517			4,057			1,341			39			(3		)	8,951
Claims, Benefits and Expenses
Net incurred claims and benefits	1,657			2,296			1,526			(3		)	—			5,476
Policyholders’ dividends	(3		)	8			8			—			—			13
Amortization of deferred acquisition costs	568			585			23			—			—			1,176
Other insurance related expenses	294			540			143			6			(3		)	980
Other expenses	191			53			19			170			—			433
Total claims, benefits and expenses	2,707			3,482			1,719			173			(3		)	8,078
Operating income (loss) from continuing operations before income tax	810			575			(378		)	(134		)	—			873
Income tax (expense) benefit on operating income (loss)	(281		)	(204		)	170			68			—			(247		)
Net operating (income) loss, after-tax, attributable to noncontrolling interests	(12		)	(4		)	—			—			—			(16		)
Net operating income (loss) from continuing operations attributable to CNA	517			367			(208		)	(66		)	—			610
Net realized investment gains (losses), pretax	(5		)	16			(7		)	(6		)	—			(2		)
Income tax (expense) benefit on net realized investment gains (losses)	2			(2		)	2			3			—			5
Net realized investment gains (losses)	(3		)	14			(5		)	(3		)	—			3
Net income (loss) from continuing operations attributable to CNA	$	514		$	381		$	(213	)	$	(69	)	$	—		$	613
____________________
(a)	Related to business in property and casualty companies only.
Revenues by line of business	'
	Revenues by Line of Business
	Years ended December 31
	(In millions)	2013			2012			2011
	CNA Specialty
	International	$	239		$	220		$	210
	Management & Professional Liability	2,836			2,723			2,541
	Surety	490			485			472
	Warranty & Alternative Risks	350			314			289
	CNA Specialty revenues	3,915			3,742			3,512
	CNA Commercial
	Commercial Insurance	3,230			3,200			2,953
	International	376			369			539
	Small Business	754			669			581
	CNA Commercial revenues	4,360			4,238			4,073
	Hardy revenues	366			123
	Life & Group Non-Core
	Health	1,192			1,120			1,093
	Life & Annuity	232			239			229
	Other	—			36			12
	Life & Group Non-Core revenues	1,424			1,395			1,334
	Corporate & Other Non-Core revenues	52			52			33
	Eliminations	(4		)	(3		)	(3		)
	Total revenues	$	10,113		$	9,547		$	8,949

Quarterly_Financial_Data_Unaud1

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Data [Abstract]	'
Schedule of quarterly financial information	'
	Quarterly Financial Data
	2013
	(In millions, except per share data)	First		Second		Third		Fourth			Full Year
	Revenues	$	2,503	$	2,493	$	2,504	$	2,613		$	10,113
	Net income (loss) attributable to CNA	$	250	$	194	$	272	$	221		$	937
	Basic earnings (loss) per share attributable to CNA common stockholders	$	0.93	$	0.72	$	1.01	$	0.82		$	3.48
	Diluted earnings (loss) per share attributable to CNA common stockholders (a)	$	0.93	$	0.72	$	1.01	$	0.82		$	3.47
	2012
	(In millions, except per share data)	First		Second		Third		Fourth			Full Year
	Revenues	$	2,401	$	2,246	$	2,466	$	2,434		$	9,547
	Net income (loss) attributable to CNA	$	250	$	166	$	221	$	(9	)	$	628
	Basic and diluted earnings (loss) per share attributable to CNA common stockholders (a)	$	0.93	$	0.62	$	0.82	$	(0.03	)	$	2.33
	____________________
	(a)	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, 2013
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, 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
	Year ended December 31, 2011
	Deducted from assets:
	Allowance for doubtful accounts:
	Insurance and reinsurance receivables	$	285	$	(55	)	$	—		$	(27	)	$	203
	(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, 2013
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)	2013			2012			2011
	Deferred acquisition costs	$	624		$	598
	Reserves for unpaid claim and claim adjustment expenses	24,015			24,696
	Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.0% to 9.7%)	1,586			1,850
	Unearned premiums	3,718			3,610
	Net written premiums	7,348			6,964			$	6,798
	Net earned premiums	7,271			6,881			6,603
	Net investment income	2,240			2,074			1,845
	Incurred claim and claim adjustment expenses related to current year	5,113			5,266			4,901
	Incurred claim and claim adjustment expenses related to prior years	(115		)	(180		)	(429		)
	Amortization of deferred acquisition costs	1,362			1,274			1,176
	Paid claim and claim adjustment expenses	5,566			5,257			4,499

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Nov. 29, 2011
Percentage owned of outstanding common stock by majority shareholder	90.00%	'	'	'
Business Acquisition, Purchase Price	'	$231,000,000	'	'
Business Combination, Acquisition Related Costs	'	4,000,000	'	'
Sale of CNA ownership percentage of FICOH	'	'	'	50.00%
Anticipated amounts due from insureds related to losses under deductible policies	1,300,000,000	1,300,000,000	'	'
Minimum interest rate used in determining present value of obligations of structured settlements not funded by annuities	7.10%	7.10%	'	'
Maximum interest rate used in determining present value of obligations of structured settlements not funded by annuities	9.70%	9.70%	'	'
Discounted reserves for unfunded structured settlements	580,000,000	602,000,000	'	'
Discounted reserves for unfunded structure settlements, discount amount	969,000,000	1,000,000,000	'	'
Minimum interest rate used to discount workers' compensation lifetime claim reserves and accident and health claim reserves	3.00%	3.00%	'	'
Maximum interest rate used to discount workers' compensation lifetime claim reserves and accident and health claim reserves	6.80%	6.50%	'	'
Discounted reserves for worker's compensation lifetime claim reserves and accident and health claim reserves	2,400,000,000	2,200,000,000	'	'
Discounted reserves for worker's compensation lifetime claim reserves and accident and health claim reserves, discount amount	617,000,000	837,000,000	'	'
Minimum interest rate used to calculate reserves for long term care products	4.50%	5.00%	'	'
Maximum interest rate used to calculate reserves for payout annuity contracts	7.90%	7.40%	'	'
Minimum interest rate used to calculate reserves for payout annuity contracts	5.00%	5.00%	'	'
Maximum interest rate used to calculate reserves for payout annuity contracts	8.70%	8.70%	'	'
Increase in insurance reserves due to unlocking actuarial assumptions related to payout annuity contracts	'	33,000,000	'	'
Liability balance for guaranty fund	143,000,000	143,000,000	'	'
Related assets for premium tax offsets included in other assets	1,000,000	2,000,000	'	'
Percentage of billed receivables compared to total reinsurance receivables	'5% or less	'	'	'
Deposit assets	3,000,000	3,000,000	'	'
Deposit liabilities	130,000,000	125,000,000	'	'
Deferred acquisition costs, net of shadow adjustment	342,000,000	369,000,000	'	'
Investments in life settlement contracts	88,000,000	100,000,000	'	'
Increase (decrease) in fair value recognized on life settlement contracts	-2,000,000	11,000,000	5,000,000	'
Gain recognized on matured life settlement contracts	15,000,000	42,000,000	28,000,000	'
Decrease in shadow adjustment, net of tax	979,000,000	'	'	'
Increase in shadow adjustment, net of tax	'	789,000,000	'	'
Reduction of net unrealized gains on investments included in AOCI due to shadow adjustments	532,000,000	1,511,000,000	'	'
Foreign currency transaction gain (loss), before tax	2,000,000	12,000,000	4,000,000	'
Weighted average number diluted shares outstanding adjustment	552,000	417,000	290,000	'
Antidilutive securities excluded from computation of earnings per share, amount	111,000	730,000	1,100,000	'
Interest paid, net	164,000,000	170,000,000	175,000,000	'
Proceeds from income tax refunds	'	29,000,000	'	'
Income taxes paid	$129,000,000	'	$61,000,000	'
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, 2013	Dec. 31, 2012
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	40	'
Life settlement contracts, fair value method, number of contracts, maturing after year five	364	'
Life settlement contracts, fair value method, number of contracts	624	'
Life settlement contracts, fair value, maturing in next twelve months	$13	'
Life settlement contracts, fair value, maturing in year two	11	'
Life settlement contracts, fair value, maturing in year three	9	'
Life settlement contracts, fair value, maturing in year four	8	'
Life settlement contracts, fair value, maturing in year five	7	'
Life settlement contracts, fair value, maturing after year five	40	'
Life settlement contracts, fair value	88	100
Life settlement contracts, fair value method, face value, maturing in next twelve months	39	'
Life settlement contracts, fair value method, face value, maturing in year two	35	'
Life settlement contracts, fair value method, face value, maturing in year three	32	'
Life settlement contracts, fair value method, face value, maturing in year four	29	'
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	217	'
Life settlement contracts, fair value method, face value	$378	'

Investments_Narrative_Details

Investments (Narrative) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Investments [Abstract]	'	'	'
Number of non-income producing fixed maturity securities	'	9	'
Fair value of non income fixed maturity security	'	$1	'
Number of investments that exceed ten percent of stockholders' equity	'	'	'
Limited partnership investments	2,720	2,462	'
Undistributed earnings of limited partnership investments	969	768	'
Percentage of limited partnerships reported on a current basis	67.00%	'	'
Percentage of limited partnerships reported on a one month lag	16.00%	'	'
Number of active limited partnership investments held	87	79	'
Percentage of limited partnerships employing hedge fund strategies focused on fixed income and equity investments	74.00%	80.00%	'
Percentage of equity related limited partnership hedge fund strategies	51.00%	'	'
Percentage of multistrategy approach limited partnership hedge fund strategies	28.00%	'	'
Percentage of distressed investments limited partnership hedge fund strategies	17.00%	'	'
Percentage of fixed income limited partnership hedge fund strategies	4.00%	'	'
Limited partnerships invested in private debt and equity	22.00%	16.00%	'
Carrying value of ten largest limited partnerships	1,471	1,309	'
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%	3.00%	4.00%
Commercial mortgage loans past due or in non-accrual status	'	'	'
Valuation allowances recorded on commercial mortgage loans	'	'	'
Future capital call commitments for limited partnership investments	381	'	'
Commitments to purchase or fund privately placed debt securities	151	'	'
Commitments to sell various privately placed debt securities	145	'	'
Carrying value of securities deposited under requirements of regulatory authorities	3,300	3,600	'
Cash and securities deposited as collateral for letters of credit	353	4	'
Carrying value of assets deposited to secure reinsurance and third party obligations	$294	$277	'

Investments_Net_investment_inc

Investments (Net investment income) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net Investment Income [Line Items]	'	'	'
Gross investment income	$2,506	$2,338	$2,112
Investment expense	-56	-56	-58
Net investment income	2,450	2,282	2,054
Fixed maturity securities [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Gross investment income	1,998	2,022	2,011
Short term investments [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Gross investment income	3	5	8
Limited partnership investments [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Gross investment income	451	251	48
Equity securities [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Gross investment income	12	12	20
Mortgage loans [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Gross investment income	23	17	9
Trading portfolio [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Gross investment income	17	24	9
Other [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Gross investment income	$2	$7	$7

Investments_Net_realized_inves

Investments (Net realized investment gains (losses)) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net realized investment gains (losses)	$31	$63	($2)
Fixed maturity securities [Member]	'	'	'
Gross realized gains	201	232	289
Gross realized losses	-146	-149	-311
Net realized investment gains (losses)	55	83	-22
Equity securities [Member]	'	'	'
Gross realized gains	13	19	10
Gross realized losses	-35	-42	-11
Net realized investment gains (losses)	-22	-23	-1
Derivative [Member]	'	'	'
Net realized investment gains (losses)	-9	-2	'
Short term investments and other [Member]	'	'	'
Net realized investment gains (losses)	$7	$5	$21

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, 2013	Dec. 31, 2012	Dec. 31, 2011
Net change in unrealized gains (losses) on investments	($2,556)	$1,875	$1,437
Fixed maturity securities [Member]	'	'	'
Net change in unrealized gains (losses) on investments	-2,541	1,871	1,442
Equity securities [Member]	'	'	'
Net change in unrealized gains (losses) on investments	-15	5	-2
Other [Member]	'	'	'
Net change in unrealized gains (losses) on investments	'	($1)	($3)

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, 2013	Dec. 31, 2012	Dec. 31, 2011
Other-than-temporary impairment losses recognized in earnings	$78	$154	$216
Corporate and other bonds [Member]	'	'	'
Other-than-temporary impairment losses recognized in earnings	22	27	95
States, municipalities and political subdivisions [Member]	'	'	'
Other-than-temporary impairment losses recognized in earnings	'	34	'
Residential mortgage-backed [Member]	'	'	'
Other-than-temporary impairment losses recognized in earnings	19	50	105
Other asset-backed [Member]	'	'	'
Other-than-temporary impairment losses recognized in earnings	2	'	6
Total asset-backed [Member]	'	'	'
Other-than-temporary impairment losses recognized in earnings	21	50	111
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	43	112	206
Common stock [Member]	'	'	'
Other-than-temporary impairment losses recognized in earnings	8	6	8
Preferred stock [Member]	'	'	'
Other-than-temporary impairment losses recognized in earnings	26	36	1
Total equity securities available-for-sale [Member]	'	'	'
Other-than-temporary impairment losses recognized in earnings	34	42	9
Short term investments [Member]	'	'	'
Other-than-temporary impairment losses recognized in earnings	$1	'	$1

Investments_Summary_of_fixed_m

Investments (Summary of fixed maturity and equity securities) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Cost or Amortized Cost	$39,490	$38,398
Gross Unrealized Gains	2,460	4,639
Gross Unrealized Losses	532	155
Estimated fair value	41,418	42,882
Corporate and other bonds [Member]	'	'
Cost or Amortized Cost	19,352	19,530
Gross Unrealized Gains	1,645	2,698
Gross Unrealized Losses	135	21
Estimated fair value	20,862	22,207
Unrealized OTTI Losses (Gains)	'	'
States, municipalities and political subdivisions [Member]	'	'
Cost or Amortized Cost	11,281	9,372
Gross Unrealized Gains	548	1,455
Gross Unrealized Losses	272	44
Estimated fair value	11,557	10,783
Unrealized OTTI Losses (Gains)	'	'
Residential mortgage-backed [Member]	'	'
Cost or Amortized Cost	4,940	5,745
Gross Unrealized Gains	123	246
Gross Unrealized Losses	92	71
Estimated fair value	4,971	5,920
Unrealized OTTI Losses (Gains)	-37	-28
Commercial mortgage-backed [Member]	'	'
Cost or Amortized Cost	1,995	1,692
Gross Unrealized Gains	90	147
Gross Unrealized Losses	22	17
Estimated fair value	2,063	1,822
Unrealized OTTI Losses (Gains)	-3	-3
Other asset-backed [Member]	'	'
Cost or Amortized Cost	945	929
Gross Unrealized Gains	13	23
Gross Unrealized Losses	3	'
Estimated fair value	955	952
Unrealized OTTI Losses (Gains)	'	'
Total asset-backed [Member]	'	'
Cost or Amortized Cost	7,880	8,366
Gross Unrealized Gains	226	416
Gross Unrealized Losses	117	88
Estimated fair value	7,989	8,694
Unrealized OTTI Losses (Gains)	-40	-31
U.S. Treasury and obligations of government-sponsored enterprises [Member]	'	'
Cost or Amortized Cost	139	172
Gross Unrealized Gains	6	11
Gross Unrealized Losses	1	1
Estimated fair value	144	182
Unrealized OTTI Losses (Gains)	'	'
Foreign Government Debt Securities [Member]	'	'
Cost or Amortized Cost	531	588
Gross Unrealized Gains	15	25
Gross Unrealized Losses	3	'
Estimated fair value	543	613
Unrealized OTTI Losses (Gains)	'	'
Redeemable preferred stock [Member]	'	'
Cost or Amortized Cost	92	113
Gross Unrealized Gains	10	13
Gross Unrealized Losses	'	1
Estimated fair value	102	125
Unrealized OTTI Losses (Gains)	'	'
Total fixed maturity securities available-for-sale [Member]	'	'
Cost or Amortized Cost	39,275	38,141
Gross Unrealized Gains	2,450	4,618
Gross Unrealized Losses	528	155
Estimated fair value	41,197	42,604
Unrealized OTTI Losses (Gains)	-40	-31
Total fixed maturity securities trading [Member]	'	'
Cost or Amortized Cost, Trading Securities	36	29
Gross Unrealized Gains, Trading Securities	'	'
Gross Unrealized Losses, Trading Securities	'	'
Estimated Fair Value, Trading Securities	36	29
Common stock [Member]	'	'
Cost or Amortized Cost	36	38
Gross Unrealized Gains	9	14
Gross Unrealized Losses	'	'
Estimated fair value	45	52
Preferred stock [Member]	'	'
Cost or Amortized Cost	143	190
Gross Unrealized Gains	1	7
Gross Unrealized Losses	4	'
Estimated fair value	140	197
Total equity securities available-for-sale [Member]	'	'
Cost or Amortized Cost	179	228
Gross Unrealized Gains	10	21
Gross Unrealized Losses	4	'
Estimated fair value	$185	$249

Investments_Securities_in_a_gr

Investments (Securities in a gross unrealized loss position) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	$9,256	$1,819
Gross Unrealized Losses, Less than 12 Months	388	27
Estimated Fair Value, 12 Months or Longer	544	866
Gross Unrealized Losses, 12 Months or Longer	144	128
Estimated Fair Value, Total	9,800	2,685
Gross Unrealized Losses, Total	532	155
Corporate and other bonds [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	3,592	846
Gross Unrealized Losses, Less than 12 Months	129	13
Estimated Fair Value, 12 Months or Longer	72	108
Gross Unrealized Losses, 12 Months or Longer	6	8
Estimated Fair Value, Total	3,664	954
Gross Unrealized Losses, Total	135	21
States, municipalities and political subdivisions [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	3,251	254
Gross Unrealized Losses, Less than 12 Months	197	5
Estimated Fair Value, 12 Months or Longer	129	165
Gross Unrealized Losses, 12 Months or Longer	75	39
Estimated Fair Value, Total	3,380	419
Gross Unrealized Losses, Total	272	44
Residential mortgage-backed [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	1,293	583
Gross Unrealized Losses, Less than 12 Months	29	5
Estimated Fair Value, 12 Months or Longer	343	452
Gross Unrealized Losses, 12 Months or Longer	63	66
Estimated Fair Value, Total	1,636	1,035
Gross Unrealized Losses, Total	92	71
Commercial mortgage-backed [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	640	85
Gross Unrealized Losses, Less than 12 Months	22	2
Estimated Fair Value, 12 Months or Longer	'	141
Gross Unrealized Losses, 12 Months or Longer	'	15
Estimated Fair Value, Total	640	226
Gross Unrealized Losses, Total	22	17
Other asset-backed [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	269	'
Gross Unrealized Losses, Less than 12 Months	3	'
Estimated Fair Value, 12 Months or Longer	'	'
Gross Unrealized Losses, 12 Months or Longer	'	'
Estimated Fair Value, Total	269	'
Gross Unrealized Losses, Total	3	'
Total asset-backed [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	2,202	668
Gross Unrealized Losses, Less than 12 Months	54	7
Estimated Fair Value, 12 Months or Longer	343	593
Gross Unrealized Losses, 12 Months or Longer	63	81
Estimated Fair Value, Total	2,545	1,261
Gross Unrealized Losses, Total	117	88
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	13	23
Gross Unrealized Losses, Less than 12 Months	1	1
Estimated Fair Value, 12 Months or Longer	'	'
Gross Unrealized Losses, 12 Months or Longer	'	'
Estimated Fair Value, Total	13	23
Gross Unrealized Losses, Total	1	1
Foreign Government Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	111	'
Gross Unrealized Losses, Less than 12 Months	3	'
Estimated Fair Value, 12 Months or Longer	'	'
Gross Unrealized Losses, 12 Months or Longer	'	'
Estimated Fair Value, Total	111	'
Gross Unrealized Losses, Total	3	'
Redeemable preferred stock [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	'	28
Gross Unrealized Losses, Less than 12 Months	'	1
Estimated Fair Value, 12 Months or Longer	'	'
Gross Unrealized Losses, 12 Months or Longer	'	'
Estimated Fair Value, Total	'	28
Gross Unrealized Losses, Total	'	1
Total fixed maturity securities available-for-sale [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	9,169	1,819
Gross Unrealized Losses, Less than 12 Months	384	27
Estimated Fair Value, 12 Months or Longer	544	866
Gross Unrealized Losses, 12 Months or Longer	144	128
Estimated Fair Value, Total	9,713	2,685
Gross Unrealized Losses, Total	528	155
Preferred stock [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Estimated Fair Value, Less than 12 Months	87	'
Gross Unrealized Losses, Less than 12 Months	4	'
Estimated Fair Value, 12 Months or Longer	'	'
Gross Unrealized Losses, 12 Months or Longer	'	'
Estimated Fair Value, Total	87	'
Gross Unrealized Losses, Total	$4	'

Investments_Activity_related_t

Investments (Activity related to the pretax fixed maturity credit loss component reflected within retained earnings for securities still held for which a portion of an OTTI loss was recognized in OCI) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]	'	'	'
Beginning balance of credit losses on fixed maturity securities	$95	$92	$141
Additional credit losses for securities for which an OTTI loss was previously recognized	2	23	39
Credit losses for securities for which an OTTI loss was previously recognized	'	2	11
Reductions for securities sold during the period	-23	-14	-67
Reductions for securities the Company intends to sell or more likely than not will be required to sell	'	-8	-32
Ending balance of credit losses on fixed maturity securities	$74	$95	$92

Investments_Contractual_maturi

Investments (Contractual maturity) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Investments [Abstract]	'	'
Due in one year or less, cost or amortized cost	$2,420	$1,648
Due after one year through five years, cost or amortized cost	9,496	13,603
Due after five years through ten years, cost or amortized cost	11,667	8,726
Due after ten years, cost or amortized cost	15,692	14,164
Total Amortized Cost Basis	39,275	38,141
Due in one year or less, estimated fair value	2,455	1,665
Due after one year through five years, estimated fair value	10,068	14,442
Due after five years through ten years, estimated fair value	11,954	9,555
Due after ten years, estimated fair value	16,720	16,942
Total Estimated Fair Value	$41,197	$42,604

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Summary of Derivative Instruments [Abstract]	'	'
Fair value of cash collateral by the Company	'	$1
Fair value of cash collateral received from counterparties	'	'
Derivative transactions entered into	2,743	1,581
Derivative transactions terminated	$2,822	$1,543

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Summary of aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments) (Details) (Not Designated as Hedging Instrument [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Derivative [Line Items]	'	'
Contractual/notional amount	'	$84
Estimated fair value asset	'	'
Estimated fair value (liability)	'	-3
Credit default swap - purchased protection [Member]	'	'
Derivative [Line Items]	'	'
Contractual/notional amount	'	20
Estimated fair value asset	'	'
Estimated fair value (liability)	'	-1
Currency forwards [Member]	'	'
Derivative [Line Items]	'	'
Contractual/notional amount	'	59
Estimated fair value asset	'	'
Estimated fair value (liability)	'	-2
Equity warrants [Member]	'	'
Derivative [Line Items]	'	'
Contractual/notional amount	5	5
Estimated fair value asset	'	'
Estimated fair value (liability)	'	'

Fair_Value_Assets_and_liabilit

Fair Value (Assets and liabilities measured at fair value on a recurring basis) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
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	$43,073	$45,145
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	20,898	22,236
States, municipalities and political subdivisions [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	11,557	10,783
Residential mortgage-backed [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	4,971	5,920
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	2,063	1,822
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	955	952
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	7,989	8,694
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	144	182
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	543	613
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	102	125
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	41,233	42,633
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	185	249
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	54	59
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	1,332	1,792
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	88	100
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	312
Derivative financial instruments, included in Other liabilities [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	1,179	1,452
Fair value of liabilities, measured on a recurring basis	'	'
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	33	6
Level 1 [Member] | States, municipalities and political subdivisions [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
Level 1 [Member] | Residential mortgage-backed [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
Level 1 [Member] | Commercial mortgage-backed [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
Level 1 [Member] | Other asset-backed [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
Level 1 [Member] | Total asset-backed [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
Level 1 [Member] | U.S. Treasury and obligations of government-sponsored enterprises [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	116	158
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	81	140
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	45	40
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	275	344
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	126	117
Level 1 [Member] | Other invested assets [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
Level 1 [Member] | Short term investments [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	769	987
Level 1 [Member] | Life settlement contracts, included in Other assets [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
Level 1 [Member] | Separate account business [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	9	4
Level 1 [Member] | Derivative financial instruments, included in Other liabilities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of liabilities, measured on a recurring basis	'	'
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	40,591	42,299
Fair value of liabilities, measured on a recurring basis	'	-2
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	20,661	22,011
Level 2 [Member] | States, municipalities and political subdivisions [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	11,486	10,687
Level 2 [Member] | Residential mortgage-backed [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	4,640	5,507
Level 2 [Member] | Commercial mortgage-backed [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	1,912	1,693
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	509	584
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	7,061	7,784
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	28	24
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	462	473
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	57	59
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	39,755	41,038
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	48	98
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	54	58
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	563	799
Level 2 [Member] | Life settlement contracts, included in Other assets [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
Level 2 [Member] | Separate account business [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	171	306
Level 2 [Member] | Derivative financial instruments, included in Other liabilities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of liabilities, measured on a recurring basis	'	-2
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	1,303	1,394
Fair value of liabilities, measured on a recurring basis	'	-1
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	204	219
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	71	96
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	331	413
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	151	129
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	446	368
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	928	910
Level 3 [Member] | U.S. Treasury and obligations of government-sponsored enterprises [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets, measured on a recurring basis	'	'
Level 3 [Member] | Foreign Government 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	'	'
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	'	26
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	1,203	1,251
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	11	34
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	'	1
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	'	6
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	88	100
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	2
Level 3 [Member] | Derivative financial instruments, included in Other liabilities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of liabilities, measured on a recurring basis	'	($1)

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, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	$1,393	$1,751
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	-5	28
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	'	33
Purchases	804	1,225
Sales	-414	-580
Settlements	-275	-494
Transfers into Level 3	94	59
Transfers out of Level 3	-294	-629
Balance, Ending, Assets	1,303	1,393
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-36	-48
Fixed maturity securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	1,251	1,507
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	9	11
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-3	27
Purchases	801	1,175
Sales	-405	-539
Settlements	-251	-373
Transfers into Level 3	94	58
Transfers out of Level 3	-293	-615
Balance, Ending, Assets	1,203	1,251
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-7	-21
Corporate and other bonds [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	219	482
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	3	6
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	'	4
Purchases	142	231
Sales	-116	-136
Settlements	-44	-88
Transfers into Level 3	51	45
Transfers out of Level 3	-51	-325
Balance, Ending, Assets	204	219
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-2	-3
States, municipalities and political subdivisions [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	96	171
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	-2	'
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	4	'
Purchases	122	14
Sales	-79	'
Settlements	-61	-89
Transfers into Level 3	18	'
Transfers out of Level 3	-27	'
Balance, Ending, Assets	71	96
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Residential mortgage-backed [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	413	452
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	4	-14
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-14	2
Purchases	116	97
Sales	-10	'
Settlements	-75	-40
Transfers into Level 3	4	'
Transfers out of Level 3	-107	-84
Balance, Ending, Assets	331	413
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-3	-18
Commercial Mortgage Backed Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	129	59
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	'	8
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	11	14
Purchases	107	165
Sales	-3	-12
Settlements	-11	-28
Transfers into Level 3	21	13
Transfers out of Level 3	-103	-90
Balance, Ending, Assets	151	129
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Other asset-backed [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	368	343
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	5	11
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-4	8
Purchases	314	615
Sales	-197	-365
Settlements	-35	-128
Transfers into Level 3	'	'
Transfers out of Level 3	-5	-116
Balance, Ending, Assets	446	368
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-2	'
Total asset-backed [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	910	854
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	9	5
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	-7	24
Purchases	537	877
Sales	-210	-377
Settlements	-121	-196
Transfers into Level 3	25	13
Transfers out of Level 3	-215	-290
Balance, Ending, Assets	928	910
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-5	-18
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	'
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	'	-1
Purchases	'	53
Sales	'	-26
Settlements	-25	'
Transfers into Level 3	'	'
Transfers out of Level 3	'	'
Balance, Ending, Assets	'	26
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Equity securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	34	67
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	-27	-36
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	3	6
Purchases	2	27
Sales	'	-16
Settlements	'	'
Transfers into Level 3	'	'
Transfers out of Level 3	-1	-14
Balance, Ending, Assets	11	34
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-27	-38
Other invested assets, including derivatives, net	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	'	10
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	'	'
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	'	'
Purchases	'	'
Sales	-1	'
Settlements	1	-10
Transfers into Level 3	'	'
Transfers out of Level 3	'	'
Balance, Ending, Assets	'	'
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Short-term Investments [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	6	27
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	'	'
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	'	'
Purchases	'	23
Sales	-6	-4
Settlements	'	-41
Transfers into Level 3	'	1
Transfers out of Level 3	'	'
Balance, Ending, Assets	'	6
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'
Life settlement contracts, included in Other assets [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	100	117
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	13	53
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	'	'
Purchases	'	'
Sales	'	'
Settlements	-25	-70
Transfers into Level 3	'	'
Transfers out of Level 3	'	'
Balance, Ending, Assets	88	100
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	-2	11
Separate account business [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, Beginning, Assets	2	23
Net realized investment gains (losses) and net change in unrealized appreciation (depreciation) included in net income (loss)	'	'
Net change in unrealized appreciation (depreciation) included in other comprehensive income (loss)	'	'
Purchases	1	'
Sales	-2	-21
Settlements	'	'
Transfers into Level 3	'	'
Transfers out of Level 3	'	'
Balance, Ending, Assets	1	2
Unrealized gains (losses) on Level 3 assets and liabilities held at balance sheet date recognized in net income (loss)	'	'

Fair_Value_Narrative_Details

Fair Value (Narrative) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]	'	'
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	'	$106
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	'	$72

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, 2013	Dec. 31, 2012
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Assets, Fair Value Disclosure	142	121
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member] | Minimum [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Expected call date	'	3.3
Credit spread	1.74%	'
Credit spread adjustment	'	0.02%
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member] | Maximum [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Expected call date	'	5.3
Credit spread	19.90%	'
Credit spread adjustment	'	0.48%
Fixed maturity securities [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Expected call date	'	4.3
Credit spread	3.98%	'
Credit spread adjustment	'	0.17%
Fixed maturity securities [Member] | Market Approach Valuation Technique [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Assets, Fair Value Disclosure	'	72
Fixed maturity securities [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Private offering price	'	42.39
Fixed maturity securities [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Private offering price	'	102.32
Fixed maturity securities [Member] | Market Approach Valuation Technique [Member] | Weighted Average [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Private offering price	'	100.11
Equity securities [Member] | Market Approach Valuation Technique [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Assets, Fair Value Disclosure	10	34
Equity securities [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Private offering price	360.12	4.54
Equity securities [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Private offering price	4,267.66	3,842
Equity securities [Member] | Market Approach Valuation Technique [Member] | Weighted Average [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Private offering price	1,147.95	571.17
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	88	100
Life settlement contracts, included in Other assets [Member] | Income Approach Valuation Technique [Member] | Minimum [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Mortality assumption	70.00%	69.00%
Life settlement contracts, included in Other assets [Member] | Income Approach Valuation Technique [Member] | Maximum [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Mortality assumption	743.00%	883.00%
Life settlement contracts, included in Other assets [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]	'	'
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'
Mortality assumption	191.60%	208.90%
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, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	$23	$21
Mortgage loans	508	401
Financial Liabilities [Abstract]	'	'
Short term debt	549	13
Long term debt	2,011	2,557
Carrying Amount [Member]	'	'
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	23	21
Mortgage loans	508	401
Financial Liabilities [Abstract]	'	'
Premium deposits and annuity contracts	57	100
Short term debt	549	13
Long term debt	2,011	2,557
Estimated Fair Value [Member]	'	'
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	23	21
Mortgage loans	515	418
Financial Liabilities [Abstract]	'	'
Premium deposits and annuity contracts	58	104
Short term debt	575	13
Long term debt	2,328	3,016
Level 1 [Member] | Estimated Fair Value [Member]	'	'
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	'	'
Mortgage loans	'	'
Financial Liabilities [Abstract]	'	'
Premium deposits and annuity contracts	'	'
Short term debt	'	'
Long term debt	'	'
Level 2 [Member] | Estimated Fair Value [Member]	'	'
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	'	'
Mortgage loans	'	'
Financial Liabilities [Abstract]	'	'
Premium deposits and annuity contracts	'	'
Short term debt	575	13
Long term debt	2,328	3,016
Level 3 [Member] | Estimated Fair Value [Member]	'	'
Financial Assets [Abstract]	'	'
Notes receivable for the issuance of common stock	23	21
Mortgage loans	515	418
Financial Liabilities [Abstract]	'	'
Premium deposits and annuity contracts	58	104
Short term debt	'	'
Long term debt	'	'

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Federal income taxes received from (paid to) Loews	($89)	$75	$10
Unrecognized tax benefits	'	'	'
Interest income (expense)	'	2	'
Unrecognized Tax Benefits, Income Tax Penalties Accrued	'	'	'
Accrued interest and penalties	'	'	'
Deferred tax liabilities not recognized on undistributed earnings	'	'	'
Foreign tax expense (benefit) on income from continuing operations	24	34	27
Income (loss) from continuing foreign operations	101	88	75
Tax Credit Carryforward, Amount	'	'	'
Operating Loss Carryforwards	'	'	'
Valuation allowance	'	'	'

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, 2013	Dec. 31, 2012	Dec. 31, 2011
Effective Income Tax Rate Reconciliation, Amount [Abstract]	'	'	'
Income tax expense at statutory rates	($460)	($305)	($305)
Tax benefit from tax exempt income	97	84	74
Foreign taxes and credits	-1	-13	-3
Taxes related to domestic affiliate	'	'	-21
Prior year tax adjustment	'	'	20
Other tax expense	-12	-10	-7
Income tax (expense) benefit	($376)	($244)	($242)

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, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Expense (Benefit), Continuing Operations [Abstract]	'	'	'
Current tax (expense) benefit	($299)	($97)	($54)
Deferred income tax (expense) benefit	-77	-147	-188
Income tax (expense) benefit	($376)	($244)	($242)

Income_Taxes_Significant_compo

Income Taxes (Significant components of the Company's deferred tax assets and liabilities) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Deferred Tax Assets:	'	'
Property and casualty claim and claim adjustment expense reserves	$289	$352
Unearned premium reserves	178	162
Receivables	50	60
Employee benefits	187	384
Life settlement contracts	46	45
Deferred retroactive reinsurance benefit	66	'
Other assets	149	160
Gross deferred tax assets	965	1,163
Deferred Tax Liabilities:	'	'
Investment valuation differences	68	38
Deferred acquisition costs	232	238
Net unrealized gains	383	737
Other liabilities	62	57
Gross deferred tax liabilities	745	1,070
Net deferred tax asset (liability)	$220	$93

Claim_and_Claim_Adjustment_Exp2

Claim and Claim Adjustment Expense Reserves (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Catastrophe losses net of reinsurance	$169,000,000	$391,000,000	$222,000,000	'
(Favorable) unfavorable net prior year development, Life & Group	-9,000,000	-11,000,000	-29,000,000	'
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	189,000,000	'	'	'
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	$3,100,000,000	'	'	'

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, 2013		Dec. 31, 2012		Dec. 31, 2011
Reserves, beginning of year:	'		'		'
Gross	$24,763		$24,303		$25,496
Ceded	5,126		5,020		6,122
Net reserves, beginning of year	19,637		19,283		19,374
Change in net reserves due to acquisition (disposition) of subsidiaries	'		291		-277
Net incurred claim and claim adjustment expenses:	'		'		'
Provision for insured events of current year	5,114		5,273		4,904
Increase (decrease) in provision for insured events of prior years	-115		-182		-429
Amortization of discount	154		145		135
Total net incurred (a)	5,153	[1]	5,236	[1]	4,610	[1]
Net payments attributable to:	'		'		'
Current year events	-981		-988		-1,029
Prior year events	-4,588		-4,280		-3,473
Total net payments	-5,569		-5,268		-4,502
Foreign currency translation adjustment and other	-104		95		78
Net reserves, end of year	19,117		19,637		19,283
Ceded reserves, end of year	4,972		5,126		5,020
Gross reserves, end of year	$24,089		$24,763		$24,303
[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, 2013	Dec. 31, 2012	Dec. 31, 2011
Increase (decrease) in provision for insured events of prior years	($115)	($182)	($429)
Property and casualty reserve development [Member]	'	'	'
Increase (decrease) in provision for insured events of prior years	-115	-180	-429
Life reserve development in life company [Member]	'	'	'
Increase (decrease) in provision for insured events of prior years	'	($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, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Gross Case Reserves	$12,262	$12,668	'	'
Gross IBNR Reserves	11,827	12,095	'	'
Total Gross Carried Claim and Claim Adjustment Expense Reserves	24,089	24,763	24,303	25,496
Net Case Reserves	10,176	10,356	'	'
Net IBNR Reserves	8,941	9,281	'	'
Total Net Carried Claim and Claim Adjustment Expense Reserves	19,117	19,637	19,283	19,374
CNA Specialty [Member]	'	'	'	'
Gross Case Reserves	2,270	2,292	'	'
Gross IBNR Reserves	4,419	4,456	'	'
Total Gross Carried Claim and Claim Adjustment Expense Reserves	6,689	6,748	'	'
Net Case Reserves	2,024	2,008	'	'
Net IBNR Reserves	4,142	4,104	'	'
Total Net Carried Claim and Claim Adjustment Expense Reserves	6,166	6,112	'	'
CNA Commercial [Member]	'	'	'	'
Gross Case Reserves	5,829	6,146	'	'
Gross IBNR Reserves	4,820	5,180	'	'
Total Gross Carried Claim and Claim Adjustment Expense Reserves	10,649	11,326	'	'
Net Case Reserves	5,358	5,611	'	'
Net IBNR Reserves	4,269	4,600	'	'
Total Net Carried Claim and Claim Adjustment Expense Reserves	9,627	10,211	'	'
Hardy [Member]	'	'	'	'
Gross Case Reserves	275	333	'	'
Gross IBNR Reserves	111	188	'	'
Total Gross Carried Claim and Claim Adjustment Expense Reserves	386	521	'	'
Net Case Reserves	159	192	'	'
Net IBNR Reserves	75	82	'	'
Total Net Carried Claim and Claim Adjustment Expense Reserves	234	274	'	'
Life and Group Non-Core [Member]	'	'	'	'
Gross Case Reserves	2,748	2,690	'	'
Gross IBNR Reserves	310	316	'	'
Total Gross Carried Claim and Claim Adjustment Expense Reserves	3,058	3,006	'	'
Net Case Reserves	2,352	2,253	'	'
Net IBNR Reserves	271	275	'	'
Total Net Carried Claim and Claim Adjustment Expense Reserves	2,623	2,528	'	'
Corporate and Other [Member]	'	'	'	'
Gross Case Reserves	1,140	1,207	'	'
Gross IBNR Reserves	2,167	1,955	'	'
Total Gross Carried Claim and Claim Adjustment Expense Reserves	3,307	3,162	'	'
Net Case Reserves	283	292	'	'
Net IBNR Reserves	184	220	'	'
Total Net Carried Claim and Claim Adjustment Expense Reserves	$467	$512	'	'

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, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]	'	'	'
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($118)	($205)	($423)
Pretax (favorable) unfavorable premium development, excluding Life & Group	-42	-46	-8
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-160	-251	-431
CNA Specialty [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	-230	-135	-217
Pretax (favorable) unfavorable premium development, excluding Life & Group	-17	-15	-28
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-247	-150	-245
CNA Commercial [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	104	-46	-204
Pretax (favorable) unfavorable premium development, excluding Life & Group	-9	-35	21
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	95	-81	-183
Hardy [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	14	-11	'
Pretax (favorable) unfavorable premium development, excluding Life & Group	-17	3	'
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	-3	-8	'
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	-6	-13	-2
Pretax (favorable) unfavorable premium development, excluding Life & Group	1	1	-1
Total pretax (favorable) unfavorable net prior year development, excluding Life & Group	($5)	($12)	($3)

Claim_and_Claim_Adjustment_Exp7

Claim and Claim Adjustment Expense Reserves (Net prior year claim and allocated claim adjustment expense reserve development for CNA Specialty segment) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($118)	($205)	($423)
CNA Specialty [Member]	'	'	'
Medical Professional Liability	-35	-32	-92
Other Professional Liability and Management Liability	-101	-22	-78
Surety	-74	-63	-47
Warranty	-3	-5	-13
Other	-17	-13	13
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($230)	($135)	($217)

Claim_and_Claim_Adjustment_Exp8

Claim and Claim Adjustment Expense Reserves (Net prior year claim and allocated claim adjustment expense reserve development for CNA Commercial segment) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($118)	($205)	($423)
CNA Commercial [Member]	'	'	'
Commercial Auto	15	27	-98
General Liability	59	-64	-39
Workers' Compensation	92	15	36
Property and Other	-62	-24	-103
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	$104	($46)	($204)

Claim_and_Claim_Adjustment_Exp9

Claim and Claim Adjustment Expense Reserves Net prior year claim and allocated claim adjustment expense reserve development for Hardy segment (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	($118)	($205)	($423)
Hardy [Member]	'	'	'
Marine and Aviation	2	'	'
Non-Marine Property	12	-7	'
Property Treaty	-5	-3	'
Specialty	-6	-1	'
Commutation	11	'	'
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group	$14	($11)	'

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, 2013	Dec. 31, 2012	Dec. 31, 2011
Loss Portfolio Transfer [Member]	'	'	'
Net AEP adverse development before consideration of LPT	$363	$261	$84
Provision for uncollectible third-party reinsurance on AEP	140	'	'
Additional amounts ceded under LPT	503	261	84
Retroactive reinsurance benefit recognized	-314	-261	-84
Pretax impact of unrecognized deferred retroactive reinsurance benefit	$189	'	'

Reinsurance_Narrative_Details

Reinsurance (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Funds held under reinsurance agreements, liability	$3,900	$3,700	'
Reinsurance recoveries reported in insurance claims and policyholders' benefits reported on the Consolidated Statement of Operations	1,527	1,514	1,285
Ceded claim and claim adjustment expense reserves, future policy benefits and policyholder funds as the result of business operations sold in prior years	1,066	1,131	'
Subsidiaries of Berkshire Hathaway Group [Member]	'	'	'
Largest Recoverables From Single Reinsurer	2,900	'	'
Subsidiaries of Swiss Re Group [Member]	'	'	'
Largest Recoverables From Single Reinsurer	850	'	'
Subsidiaries of Hartford Insurance Group [Member]	'	'	'
Largest Recoverables From Single Reinsurer	350	'	'
Significant Captive Program [Member]	'	'	'
Direct and ceded earned premiums	2,156	1,794	1,500
Reinsurance recoveries reported in insurance claims and policyholders' benefits reported on the Consolidated Statement of Operations	$712	$814	$790

Reinsurance_Components_of_Rein

Reinsurance (Components of Reinsurance Receivables) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Reinsurance Disclosures [Abstract]	'	'	'	'
Ceded claim and claim adjustment expenses	$4,972	$5,126	$5,020	$6,122
Ceded future policy benefits	733	759	'	'
Ceded policyholders' funds	35	35	'	'
Reinsurance receivables related to paid losses	348	311	'	'
Reinsurance receivables	6,088	6,231	'	'
Allowance for uncollectible reinsurance	-71	-73	'	'
Reinsurance receivables, net of allowance for uncollectible reinsurance	$6,017	$6,158	'	'

Reinsurance_Components_of_Earn

Reinsurance (Components of Earned Premiums) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Direct premiums earned	$9,624	$8,919	$8,434
Assumed premiums earned	306	244	145
Ceded premiums earned	2,659	2,281	1,976
Net earned premiums	7,271	6,882	6,603
Property and Casualty Insurance [Member]	'	'	'
Direct premiums earned	9,063	8,354	7,858
Assumed premiums earned	258	197	95
Ceded premiums earned	2,609	2,229	1,919
Net earned premiums	6,712	6,322	6,034
Accident and Health Insurance [Member]	'	'	'
Direct premiums earned	512	514	521
Assumed premiums earned	48	47	50
Ceded premiums earned	1	1	2
Net earned premiums	559	560	569
Life Insurance [Member]	'	'	'
Direct premiums earned	49	51	55
Assumed premiums earned	'	'	'
Ceded premiums earned	49	51	55
Net earned premiums	'	'	'
Percentage of assumed premiums earned to net premiums earned [Member]	'	'	'
Percentage of assumed premium earned to premium earned net	4.20%	3.50%	2.20%
Percentage of assumed premiums earned to net premiums earned [Member] | Property and Casualty Insurance [Member]	'	'	'
Percentage of assumed premium earned to premium earned net	3.80%	3.10%	1.60%
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%	8.40%	8.80%
Percentage of assumed premiums earned to net premiums earned [Member] | Life Insurance [Member]	'	'	'
Percentage of assumed premium earned to premium earned net	'	'	'

Reinsurance_Components_of_Writ

Reinsurance (Components of Written Premiums) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Direct premiums written	$9,658		$9,025		$8,560
Assumed premiums written	296		216		152
Ceded premiums written	2,606		2,277		1,914
Net written premiums	7,348	[1]	6,964	[1]	6,798	[1]
Property and Casualty Insurance [Member]	'		'		'
Direct premiums written	9,103		8,467		7,976
Assumed premiums written	249		169		102
Ceded premiums written	2,556		2,225		1,857
Net written premiums	6,796		6,411		6,221
Accident and Health Insurance [Member]	'		'		'
Direct premiums written	506		507		529
Assumed premiums written	47		47		50
Ceded premiums written	1		1		2
Net written premiums	552		553		577
Life Insurance [Member]	'		'		'
Direct premiums written	49		51		55
Assumed premiums written	'		'		'
Ceded premiums written	49		51		55
Net written premiums	'		'		'
Percentage of assumed premiums written to net premiums written [Member]	'		'		'
Percentage of assumed premium written to premium written net	4.00%		3.10%		2.20%
Percentage of assumed premiums written to net premiums written [Member] | Property and Casualty Insurance [Member]	'		'		'
Percentage of assumed premium written to premium written net	3.70%		2.60%		1.60%
Percentage of assumed premiums written to net premiums written [Member] | Accident and Health Insurance [Member]	'		'		'
Percentage of assumed premium written to premium written net	8.50%		8.50%		8.70%
Percentage of assumed premiums written to net premiums written [Member] | Life Insurance [Member]	'		'		'
Percentage of assumed premium written to premium written net	'		'		'
[1]	(a)Related to business in property and casualty companies only.

Reinsurance_Components_of_Life

Reinsurance (Components of Life Insurance Inforce) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reinsurance Disclosures [Abstract]	'	'	'
Life Insurance Inforce, Direct	$5,127	$5,713	$6,528
Life Insurance Inforce, Assumed	'	'	'
Life Insurance Inforce, Ceded	5,118	5,702	6,515
Life Insurance Inforce, Net	$9	$11	$13

Debt_Narrative_Details

Debt (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Federal Home Loan Bank Stock	$16
Federal Home Loan Bank, Advances, General Debt Obligations, Maximum Amount Available	330
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	'
Line of Credit, Current borrowing capacity	250
Line of Credit, Additional borrowing capacity available	100
Line of Credit, Minimum Net Worth Required for Compliance	8,200
Line of Credit, Amount Outstanding	'

Debt_Schedule_of_debt_instrume

Debt (Schedule of debt instruments) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Short term debt	$549	$13
Long term debt	2,011	2,557
Total debt	2,560	2,570
Senior notes 5.850%, face amount $549, due December 15, 2014	'	'
Long term debt	'	548
Senior notes 6.500%, face amount of $350, due August 15, 2016	'	'
Long term debt	349	348
Senior notes 6.950%, face amount $150, due January 15, 2018	'	'
Long term debt	149	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	496
Senior notes 5.750%, face amount $400, due August 15, 2021	'	'
Long term debt	397	397
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
Other debt	'	'
Short term debt	'	13
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, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Debt Disclosure [Abstract]	'	'
Repayments of principal in the next twelve months	$549	'
Repayments of principal in year two	'	'
Repayments of principal in year three	350	'
Repayments of principal in year four	'	'
Repayments of principal in year five	150	'
Repayments of principal after year five	1,523	'
Less discount	-12	'
Total debt	$2,560	$2,570

Benefit_Plans_Narrative_detail

Benefit Plans (Narrative) (details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Future capital call commitments for limited partnership investments	$381	'	'
Share-based compensation arrangement by share-based payment award, number of shares authorized	6	'	'
Share-based compensation arrangement by share-based payment award, number of shares available for grant	1.5	'	'
Allocated share-based compensation expense	10	9	6
Employee service share-based compensation, tax benefit from compensation expense	3	3	2
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized	14	'	'
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, period for recognition	'1 year 8 months 15 days	'	'
Pension Plans, Defined Benefit [Member]	'	'	'
Defined benefit plan, accumulated benefit obligation	2,889	3,187	'
Future capital call commitments for limited partnership investments	102	'	'
Limited partnership equity related hedge fund strategy plan assets	58.00%	'	'
Limited partnership hedge fund multi strategy plan assets	37.00%	'	'
Limited partnership hedge fund strategy distressed investments plan assets	5.00%	'	'
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	56	'	'
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, Defined Benefit [Member]	'	'	'
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	'	'
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%	'	'
Defined Contribution Pension [Member]	'	'	'
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	20.00%	'	'
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	'	'
Liability of the CNA Savings Plan included in Separate account liabilities on the Consolidated Balance Sheets	129	256	'
Company Contribution of Eligible Compensation, Depending on Age, Percent	'3% or 5%	'	'
Benefit expense for the Company's savings plan	$71	$70	$60
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	'	'
Defined Contribution Plan, Employer Discretionary Contribution Amount, Percent	2.00%	'	'
Stock Options and SARs [Member]	'	'	'
Vesting Period Following Date of Grant, in Years	'4	'	'
Stock Options and SARs, Maximum Term Following Date of Grant, in Years	'10	'	'
Restricted Shares [Member]	'	'	'
Vesting Period Following Date of Grant, in Years	'4	'	'
Restricted Stock Units (RSUs) [Member]	'	'	'
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]	'	'	'
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	'	'

Benefit_Plans_Funded_Status_De

Benefit Plans (Funded Status) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]	'	'	'
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]	'	'	'
Benefit obligation at January 1	$3,271	$3,003	'
Service cost	12	12	13
Interest cost	121	135	146
Participants' contributions	'	'	'
Actuarial (gain) loss	-289	266	'
Benefits paid	-165	-164	'
Settlements	-8	'	'
Foreign currency translation and other	1	19	'
Benefit obligation at December 31	2,943	3,271	3,003
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'	'
Fair value of plan assets at January 1	2,425	2,212	'
Actual return on plan assets	311	245	'
Company contributions	92	115	'
Participants' contributions	'	'	'
Benefits paid	-165	-164	'
Settlements	-8	'	'
Foreign currency translation and other	1	17	'
Fair value of plan assets at December 31	2,656	2,425	2,212
Defined Benefit Plan, Funded Status of Plan [Abstract]	'	'	'
Funded status	-287	-846	'
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]	'	'	'
Other assets	9	'	'
Other liabilities	-296	-846	'
Net amount recognized on balance sheets	-287	-846	'
Amounts recognized in Accumulated other comprehensive income not yet recognized in net periodic cost (benefit)[Abstract]	'	'	'
Prior service credit	'	'	'
Net actuarial (gain) loss	745	1,213	'
Net amount recognized in Accumulated other comprehensive income	745	1,213	'
Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]	'	'	'
Benefit obligation at January 1	47	49	'
Service cost	1	'	1
Interest cost	1	2	3
Participants' contributions	5	5	'
Actuarial (gain) loss	-3	3	'
Benefits paid	-12	-12	'
Settlements	'	'	'
Foreign currency translation and other	1	'	'
Benefit obligation at December 31	40	47	49
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]	'	'	'
Fair value of plan assets at January 1	'	'	'
Actual return on plan assets	'	'	'
Company contributions	7	7	'
Participants' contributions	5	5	'
Benefits paid	-12	-12	'
Settlements	'	'	'
Foreign currency translation and other	'	'	'
Fair value of plan assets at December 31	'	'	'
Defined Benefit Plan, Funded Status of Plan [Abstract]	'	'	'
Funded status	-40	-47	'
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]	'	'	'
Other assets	'	'	'
Other liabilities	-40	-47	'
Net amount recognized on balance sheets	-40	-47	'
Amounts recognized in Accumulated other comprehensive income not yet recognized in net periodic cost (benefit)[Abstract]	'	'	'
Prior service credit	-98	-116	'
Net actuarial (gain) loss	8	11	'
Net amount recognized in Accumulated other comprehensive income	($90)	($105)	'

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, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost	$12	$12	$13
Interest cost on projected benefit obligation	121	135	146
Expected return on plan assets	-181	-171	-172
Amortization of net actuarial (gain) loss	47	39	25
Settlement loss	3	'	'
Net periodic (benefit) cost	2	15	12
Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost	1	'	1
Interest cost on projected benefit obligation	1	2	3
Amortization of prior service credit	-18	-18	-19
Amortization of net actuarial (gain) loss	2	1	'
Net periodic (benefit) cost	($14)	($15)	($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, 2013	Dec. 31, 2012	Dec. 31, 2011
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, [Abstract]	'	'	'
Amounts arising during the period	$422	($195)	($325)
Reclassification adjustment relating to prior service cost (credit)	-18	-18	-19
Reclassification adjustment relating to actuarial (gain) loss	49	40	25
Total increase (decrease) in Other comprehensive income	$453	($173)	($319)

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, 2013
Pension Plans, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Amortization of prior service cost (credit)	'
Amortization of net actuarial (gain) loss	25
Total estimated amounts to be recognized	25
Other Postretirement Benefit Plan, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Amortization of prior service cost (credit)	-18
Amortization of net actuarial (gain) loss	'
Total estimated amounts to be recognized	($18)

Benefit_Plans_Actuarial_Assump

Benefit Plans (Actuarial Assumptions for Benefit Obligations) (Details)	Dec. 31, 2013	Dec. 31, 2012
Pension Plans, Defined Benefit [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Discount rate	4.65%	3.80%
Expected long term rate of return	7.50%	7.75%
Rate of compensation increases	3.99%	4.07%
Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Discount rate	3.60%	2.80%

Benefit_Plans_Actuarial_Assump1

Benefit Plans (Actuarial Assumptions for Net Cost or Benefit) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Discount rate	3.80%	4.60%	5.38%
Expected long term rate of return	7.75%	8.00%	8.00%
Rate of compensation increases	4.07%	4.13%	5.03%
Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Discount rate	2.80%	3.75%	4.38%

Benefit_Plans_Fair_Value_of_Pl

Benefit Plans (Fair Value of Plan Assets Measured on a Recurring Basis) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Corporate and other bonds [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	$520	$447	'
Corporate and other bonds [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Corporate and other bonds [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	505	436	'
Corporate and other bonds [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	15	11	10
States, municipalities and political subdivisions [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	73	91	'
States, municipalities and political subdivisions [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
States, municipalities and political subdivisions [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	73	91	'
States, municipalities and political subdivisions [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Residential mortgage-backed [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	130	161	'
Residential mortgage-backed [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Residential mortgage-backed [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	130	161	'
Residential mortgage-backed [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Commercial Mortgage Backed Securities [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	106	105	'
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	106	105	'
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Other asset-backed [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	12	'	'
Other asset-backed [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Other asset-backed [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	12	'	'
Other asset-backed [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Total asset-backed [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	248	266	'
Total asset-backed [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Total asset-backed [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	248	266	'
Total asset-backed [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Fixed Maturities [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	841	804	'
Fixed Maturities [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Fixed Maturities [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	826	793	'
Fixed Maturities [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	15	11	10
Equity securities [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	605	493	'
Equity securities [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	480	386	'
Equity securities [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	117	102	'
Equity securities [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	8	5	5
Derivative Financial Instruments, Assets [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	2	1	'
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	2	1	'
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Short-term Investments [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	94	119	'
Short-term Investments [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	45	37	'
Short-term Investments [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	49	82	'
Short-term Investments [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Hedge Funds [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	969	896	'
Hedge Funds [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Hedge Funds [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	647	537	'
Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	322	359	330
Private Equity Funds [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	114	62	'
Private Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Private Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Private Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	114	62	65
Total limited partnerships [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	1,083	958	'
Total limited partnerships [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Total limited partnerships [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	647	537	'
Total limited partnerships [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	436	421	395
Other Assets [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	31	40	'
Other Assets [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Other Assets [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	31	40	'
Other Assets [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Investment Contracts with Insurance Company [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	10	'
Investment Contracts with Insurance Company [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Investment Contracts with Insurance Company [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	'	'
Investment Contracts with Insurance Company [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	'	10	10
Total assets [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	2,656	2,425	'
Total assets [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	527	424	'
Total assets [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	1,670	1,554	'
Total assets [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Defined benefit plan disclosure [Line items]	'	'	'
Fair value of plan assets	$459	$447	$420

Benefit_Plans_Reconciliation_o

Benefit Plans (Reconciliation of Level 3 Plan Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Corporate and other bonds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at December 31	$520	$447
Fixed Maturities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at December 31	841	804
Equity securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at December 31	605	493
Hedge Funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at December 31	969	896
Private Equity Funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at December 31	114	62
Total limited partnerships [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at December 31	1,083	958
Investment Contracts with Insurance Company [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at December 31	'	10
Total assets [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at December 31	2,656	2,425
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	11	10
Defined Benefit Plan, Actual Return on Plan Assets Still Held	-1	1
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	'	'
Defined Benefit Plan, Purchases, Sales, and Settlements	5	'
Defined Benefit Plan, Net transfers into (out of) Level 3	'	'
Fair value of plan assets at December 31	15	11
Fair Value, Inputs, Level 3 [Member] | Fixed Maturities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at January 1	11	10
Defined Benefit Plan, Actual Return on Plan Assets Still Held	'	1
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	-1	'
Defined Benefit Plan, Purchases, Sales, and Settlements	5	'
Defined Benefit Plan, Net transfers into (out of) Level 3	'	'
Fair value of plan assets at December 31	15	11
Fair Value, Inputs, Level 3 [Member] | Equity securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at January 1	5	5
Defined Benefit Plan, Actual Return on Plan Assets Still Held	3	'
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	'	'
Defined Benefit Plan, Purchases, Sales, and Settlements	'	'
Defined Benefit Plan, Net transfers into (out of) Level 3	'	'
Fair value of plan assets at December 31	8	5
Fair Value, Inputs, Level 3 [Member] | Hedge Funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at January 1	359	330
Defined Benefit Plan, Actual Return on Plan Assets Still Held	56	41
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	'	3
Defined Benefit Plan, Purchases, Sales, and Settlements	-77	-15
Defined Benefit Plan, Net transfers into (out of) Level 3	-16	'
Fair value of plan assets at December 31	322	359
Fair Value, Inputs, Level 3 [Member] | Private Equity Funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at January 1	62	65
Defined Benefit Plan, Actual Return on Plan Assets Still Held	'	8
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	'	'
Defined Benefit Plan, Purchases, Sales, and Settlements	52	-11
Defined Benefit Plan, Net transfers into (out of) Level 3	'	'
Fair value of plan assets at December 31	114	62
Fair Value, Inputs, Level 3 [Member] | Total limited partnerships [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at January 1	421	395
Defined Benefit Plan, Actual Return on Plan Assets Still Held	56	49
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	'	3
Defined Benefit Plan, Purchases, Sales, and Settlements	-25	-26
Defined Benefit Plan, Net transfers into (out of) Level 3	-16	'
Fair value of plan assets at December 31	436	421
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	10
Defined Benefit Plan, Actual Return on Plan Assets Still Held	'	'
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	'	'
Defined Benefit Plan, Purchases, Sales, and Settlements	-10	'
Defined Benefit Plan, Net transfers into (out of) Level 3	'	'
Fair value of plan assets at December 31	'	10
Fair Value, Inputs, Level 3 [Member] | Total assets [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at January 1	447	420
Defined Benefit Plan, Actual Return on Plan Assets Still Held	58	50
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	'	3
Defined Benefit Plan, Purchases, Sales, and Settlements	-30	-26
Defined Benefit Plan, Net transfers into (out of) Level 3	-16	'
Fair value of plan assets at December 31	$459	$447

Benefit_Plans_Estimated_Future

Benefit Plans (Estimated Future Minimum Benefit Payments to Participants) (Details) (USD $)	Dec. 31, 2013
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	$189
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	191
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	194
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	199
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	203
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	1,013
Other Postretirement Benefit Plan, Defined Benefit [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	5
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	4
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	4
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	$14

Benefit_Plans_Significant_Assu

Benefit Plans (Significant Assumptions Used to Estimate Fair Value of Stock Options and SARS) (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]	'	'
Weighted average expected life of the securities granted (in years)	'5 years 8 months 4 days	'5 years 7 months 11 days
Estimate of the underlying common stock's volatility	40.39%	39.88%
Expected dividend yield	2.10%	1.50%
Risk free interest rate	1.00%	2.20%

Benefit_Plans_Stock_Option_and

Benefit Plans (Stock Option and SARs Activity) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock options and Stock appreciation rights awards outstanding at January 1	1,158,700
Weighted-average exercise price per award outstanding at January 1	$25.93
Number of awards granted	'
Weighted-average exercise price on awards granted	'
Number of awards exercised	-117,950
Weighted-average exercise price on awards exercised	$21.19
Number of awards forfeited, canceled or expired	-4,100
Weighted-average exercise price on awards forfeited, canceled or expired	$30.66
Stock options and Stock appreciation rights awards outstanding at December 31	1,036,650
Weighted-average exercise price per award outstanding at December 31	$26.45
Aggregate intrinsic value on awards outstanding	$17
Weighted-average remaining contractual term on awards outstanding	'4 years 1 month 28 days
Number of awards outstanding, fully vested and expected to vest	1,032,849
Weighted-average exercise price per award outstanding, fully vested and expected to vest	$26.45
Aggregate intrinsic value on awards outstanding, fully vested and expected to vest	17
Weighted-average remaining contractual term on awards outstanding, fully vested and expected to vest	'4 years 1 month 25 days
Number of awards outstanding, exercisable	936,650
Weighted-average exercise price, awards outstanding, exercisable	$26.42
Aggregate intrinsic value, awards outstanding, exercisable	$15
Weighted-average remaining contractual term, awards outstanding, exercisable	'3 years 10 months 15 days

Benefit_Plans_Weightedaverage_

Benefit Plans (Weighted-average grant date fair value for awards granted, total intrinsic value for awards exercised and total fair value for awards vested) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'	'	'
Weighted-average grant date fair value	'	$8.81	$9.38
Total intrinsic value of awards exercised	$1,495,000	$548,000	$481,000
Fair value of awards vested	$1,000,000	$1,000,000	$2,000,000

Benefit_Plans_Restricted_Share

Benefit Plans (Restricted Shares, Performance-Based Restricted Stock Units and Performance Share Unit Activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Number of nonvested awards at January 1	882,321
Weighted average grant date fair value of nonvested awards at January 1	$26.15
Number of awards granted	351,364
Weighted average grant date fair value of awards granted	$31.80
Number of awards vested	-417,955
Weighted average grant date fair value of awards vested	$24.04
Number of awards forfeited, canceled or expired	-13,770
Weighted average grant date fair value of awards forfeited, canceled or expired	$28.72
Performance-based adjustment	45,714
Weighted average grant date fair value of performance-based adjustment	$28.39
Number of nonvested awards at December 31	847,674
Weighted average grant date fair value of nonvested awards at December 31	$29.61

Schedule_of_Other_Intangible_A

Schedule of Other Intangible Assets (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Amortization of deferred acquisition costs	$1,362	$1,274		$1,176
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	4	'		'
Finite-Lived Intangible Assets, Amortization Expense, Year Two	1	'		'
Finite-Lived Intangible Assets, Amortization Expense, Year Three	2	'		'
Finite-Lived Intangible Assets, Amortization Expense, Year Four	2	'		'
Finite-Lived Intangible Assets, Amortization Expense, Year Five	2	'		'
Hardy [Member]	'	'		'
Amortization of deferred acquisition costs	106	44	[1]	'
Other Intangible Assets [Member] | Hardy [Member]	'	'		'
Amortization of deferred acquisition costs	15	33		'
Amortization expense included in other operating expenses	$5	$10		'
[1]	(b)Included from 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, 2013	Dec. 31, 2012
Indefinite-lived intangible assets	$74	$73
Finite-Lived Intangible Assets	85	83
Accumulated Amortization	66	43
Total other intangible assets	159	156
Total intangible assets, accumulated amortization	66	43
Lloyds syndicate capacity [Member]	'	'
Indefinite-lived intangible assets	58	57
Agency Force [Member]	'	'
Indefinite-lived intangible assets	16	16
Value of business acquired [Member]	'	'
Finite-Lived Intangible Assets	64	62
Accumulated Amortization	63	43
Trade name [Member]	'	'
Economic useful life measured in years	'8 years	'
Finite-Lived Intangible Assets	8	8
Accumulated Amortization	2	'
Distribution channel [Member]	'	'
Economic useful life measured in years	'15 years	'
Finite-Lived Intangible Assets	13	13
Accumulated Amortization	$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, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Leases, Commitments and Contingencies, and Guarantees [Abstract]	'	'	'
Operating leases, rent expense	$46	$52	$50
Operating leases, sublease revenue	3	2	2
Maximum potential future lease payments and other related costs under guarantee on a real estate joint venture	84	'	'
Aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third party loans	702	'	'
Recorded liabilities related to indemnification agreements	$7	'	'

Operating_Leases_Commitments_a3

Operating Leases, Commitments and Contingencies, and Guarantees (Future Minimum Lease Payments and Sublease Receipts) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Operating Leases, Commitments and Contingencies, and Guarantees [Abstract]	'
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$37
Operating Leases, Future Minimum Payments, Due in Two Years	32
Operating Leases, Future Minimum Payments, Due in Three Years	29
Operating Leases, Future Minimum Payments, Due in Four Years	23
Operating Leases, Future Minimum Payments, Due in Five Years	17
Operating Leases, Future Minimum Payments, Due Thereafter	70
Operating Leases, Future Minimum Payments Due	208
Operating Leases, Future Minimum Payments Receivable, Current	2
Operating Leases, Future Minimum Payments Receivable, in Two Years	'
Operating Leases, Future Minimum Payments Receivable, in Three Years	'
Operating Leases, Future Minimum Payments Receivable, in Four Years	'
Operating Leases, Future Minimum Payments Receivable, in Five Years	'
Operating Leases, Future Minimum Payments Receivable, Thereafter	'
Operating Leases, Future Minimum Payments Receivable	$2

Stockholders_Equity_and_Statut2

Stockholders' Equity and Statutory Accounting Practices (Narrative) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Capital Required for Capital Adequacy to Risk Weighted Assets	265.00%	240.00%
Dividends payable without prior supervisory approval	$715	'
Hardy [Member]	'	'
Capital provided by CCC	$148	'

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, 2013		Dec. 31, 2012		Dec. 31, 2011
Combined Continental Casualty Companies [Member]	'		'		'
Statutory Accounting Practices [Line Items]	'		'		'
Statutory capital and surplus	$11,137	[1],[2]	$9,998	[1]	'
Statutory net income (loss)	913	[1],[2]	391	[1]	954	[1]
Life Company [Member]	'		'		'
Statutory Accounting Practices [Line Items]	'		'		'
Statutory capital and surplus	597	[2]	556		'
Statutory net income (loss)	$48	[2]	$44		$29
[1]	Represents the combined statutory surplus of CCC and its subsidiaries, including the life company.
[2]	Information derived from the statutory-basis financial statements to be filed with insurance regulators.

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) Narrative (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'	'
Pretax net unrealized gains (losses) on available-for-sale securities with OTTI losses reclassified out of AOCI and recognized in earnings	($28)	($83)
Tax (expense) benefit on pretax net unrealized gains (losses) on available-for-sale securities with OTTI losses reclassified out of AOCI and recognized in earnings	10	29
Pretax net unrealized gains (losses) on other available-for-sale securities reclassified out of AOCI and recognized in earnings	89	60
Tax (expense) benefit on pretax net unrealized gains (losses) on other available-for-sale securities reclassified out of AOCI and recognized in earnings	($31)	($21)

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income (Loss) by Component (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated other comprehensive income (loss), beginning balance	$831	'
Other comprehensive income (loss), before reclassifications	-388	'
Amounts reclassified from accumulated other comprehensive income (loss)	1	'
Other comprehensive income (loss), net of tax	-389	'
Accumulated other comprehensive income (loss), ending balance	442	'
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	1	'
Tax (expense) benefit on other comprehensive income (loss)	203	'
Tax on cumulative foreign currency translation adjustment	'	'
Cumulative foreign currency translation adjustment	'	161
Tax on pension and postretirement benefits	'	387
Pension and postretirement benefits	'	-721
Tax on net unrealized gains (losses) on investments with OTTI losses	'	-11
Net unrealized gains (losses) on investments with OTTI losses	'	20
Tax on net unrealized gains (losses) on other investments	'	-721
Net unrealized gains (losses) on other investments	'	1,371
Tax on accumulated other comprehensive income (loss)	'	-345
Net unrealized gains (losses) on investments with OTTI losses [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated other comprehensive income (loss), beginning balance	20	'
Other comprehensive income (loss), before reclassifications	6	'
Amounts reclassified from accumulated other comprehensive income (loss)	'	'
Other comprehensive income (loss), net of tax	6	'
Accumulated other comprehensive income (loss), ending balance	26	'
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	'	'
Tax (expense) benefit on other comprehensive income (loss)	-3	'
Net unrealized gains (losses) on other investments [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated other comprehensive income (loss), beginning balance	1,371	'
Other comprehensive income (loss), before reclassifications	-658	'
Amounts reclassified from accumulated other comprehensive income (loss)	21	'
Other comprehensive income (loss), net of tax	-679	'
Accumulated other comprehensive income (loss), ending balance	692	'
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	-10	'
Tax (expense) benefit on other comprehensive income (loss)	364	'
Pension and postretirement benefits [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated other comprehensive income (loss), beginning balance	-721	'
Other comprehensive income (loss), before reclassifications	275	'
Amounts reclassified from accumulated other comprehensive income (loss)	-20	'
Other comprehensive income (loss), net of tax	295	'
Accumulated other comprehensive income (loss), ending balance	-426	'
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	11	'
Tax (expense) benefit on other comprehensive income (loss)	-158	'
Cumulative foreign currency translation adjustment [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated other comprehensive income (loss), beginning balance	161	'
Other comprehensive income (loss), before reclassifications	-11	'
Amounts reclassified from accumulated other comprehensive income (loss)	'	'
Other comprehensive income (loss), net of tax	-11	'
Accumulated other comprehensive income (loss), ending balance	150	'
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	'	'
Tax (expense) benefit on other comprehensive income (loss)	'	'

Business_Segments_Narrative_De

Business Segments (Narrative) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Business Segments [Abstract]	'	'	'
Percentage of direct foreign written premiums	8.90%	9.20%	8.80%

Business_Segments_Income_State

Business Segments (Income Statement Information) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Segment Reporting Information [Line Items]	'		'		'
Net written premiums	$7,348	[1]	$6,964	[1]	$6,798	[1]
Operating Revenues	'		'		'
Net earned premiums	7,271		6,882		6,603
Net investment income	2,450		2,282		2,054
Other revenues	361		320		294
Total operating revenues	10,082		9,484		8,951
Claims, Benefits and Expenses	'		'		'
Net incurred claims and benefits	5,927		5,867		5,476
Policyholders' dividends	20		29		13
Amortization of deferred acquisition costs	1,362		1,274		1,176
Other insurance related expenses	1,017		1,049		980
Other expenses	474		456		433
Total claims, benefits and expenses	8,800		8,675		8,078
Operating income (loss) from continuing operations before income tax	1,282		809		873
Income tax (expense) benefit on operating income (loss)	-365		-222		-247
Net Operating Income (Loss), After-tax, Attributable to Noncontrolling Interests	'		'		-16
Net operating income (loss) from continuing operations attributable to CNA	917		587		610
Net realized investment gains (losses), pre-tax	31		63		-2
Income tax (expense) benefit on net realized investment gains (losses)	-11		-22		5
Net realized investment gains (losses), after tax	20		41		3
Net income (loss) from continuing operations attributable to CNA	937		628		613
CNA Specialty [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Net written premiums	3,091	[1]	2,924	[1]	2,872	[1]
Operating Revenues	'		'		'
Net earned premiums	3,004		2,898		2,796
Net investment income	657		592		500
Other revenues	257		230		221
Total operating revenues	3,918		3,720		3,517
Claims, Benefits and Expenses	'		'		'
Net incurred claims and benefits	1,704		1,831		1,657
Policyholders' dividends	6		2		-3
Amortization of deferred acquisition costs	628		614		568
Other insurance related expenses	272		301		294
Other expenses	236		206		191
Total claims, benefits and expenses	2,846		2,954		2,707
Operating income (loss) from continuing operations before income tax	1,072		766		810
Income tax (expense) benefit on operating income (loss)	-365		-262		-281
Net Operating Income (Loss), After-tax, Attributable to Noncontrolling Interests	'		'		-12
Net operating income (loss) from continuing operations attributable to CNA	707		504		517
Net realized investment gains (losses), pre-tax	-3		22		-5
Income tax (expense) benefit on net realized investment gains (losses)	1		-9		2
Net realized investment gains (losses), after tax	-2		13		-3
Net income (loss) from continuing operations attributable to CNA	705		517		514
CNA Commercial [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Net written premiums	3,312	[1]	3,373	[1]	3,350	[1]
Operating Revenues	'		'		'
Net earned premiums	3,350		3,306		3,240
Net investment income	927		854		763
Other revenues	96		40		54
Total operating revenues	4,373		4,200		4,057
Claims, Benefits and Expenses	'		'		'
Net incurred claims and benefits	2,475		2,574		2,296
Policyholders' dividends	7		11		8
Amortization of deferred acquisition costs	600		588		585
Other insurance related expenses	547		578		540
Other expenses	26		36		53
Total claims, benefits and expenses	3,655		3,787		3,482
Operating income (loss) from continuing operations before income tax	718		413		575
Income tax (expense) benefit on operating income (loss)	-250		-136		-204
Net Operating Income (Loss), After-tax, Attributable to Noncontrolling Interests	'		'		-4
Net operating income (loss) from continuing operations attributable to CNA	468		277		367
Net realized investment gains (losses), pre-tax	-13		38		16
Income tax (expense) benefit on net realized investment gains (losses)	4		-11		-2
Net realized investment gains (losses), after tax	-9		27		14
Net income (loss) from continuing operations attributable to CNA	459		304		381
Hardy [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Net written premiums	396	[1]	117	[1],[2]	'
Operating Revenues	'		'		'
Net earned premiums	361		120	[2]	'
Net investment income	4		3	[2]	'
Other revenues	'		1	[2]	'
Total operating revenues	365		124	[2]	'
Claims, Benefits and Expenses	'		'		'
Net incurred claims and benefits	162		72	[2]	'
Policyholders' dividends	'		'	[2]	'
Amortization of deferred acquisition costs	106		44	[2]	'
Other insurance related expenses	69		25	[2]	'
Other expenses	19		9	[2]	'
Total claims, benefits and expenses	356		150	[2]	'
Operating income (loss) from continuing operations before income tax	9		-26	[2]	'
Income tax (expense) benefit on operating income (loss)	1		3	[2]	'
Net operating income (loss) from continuing operations attributable to CNA	10		-23	[2]	'
Net realized investment gains (losses), pre-tax	1		-1	[2]	'
Income tax (expense) benefit on net realized investment gains (losses)	'		'	[2]	'
Net realized investment gains (losses), after tax	1		-1	[2]	'
Net income (loss) from continuing operations attributable to CNA	11		-24	[2]	'
Life and Group Non-Core [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Net written premiums	552	[1]	553	[1]	577	[1]
Operating Revenues	'		'		'
Net earned premiums	559		560		569
Net investment income	830		801		759
Other revenues	-2		34		13
Total operating revenues	1,387		1,395		1,341
Claims, Benefits and Expenses	'		'		'
Net incurred claims and benefits	1,395		1,406		1,526
Policyholders' dividends	7		16		8
Amortization of deferred acquisition costs	28		28		23
Other insurance related expenses	134		144		143
Other expenses	12		23		19
Total claims, benefits and expenses	1,576		1,617		1,719
Operating income (loss) from continuing operations before income tax	-189		-222		-378
Income tax (expense) benefit on operating income (loss)	131		132		170
Net Operating Income (Loss), After-tax, Attributable to Noncontrolling Interests	'		'		'
Net operating income (loss) from continuing operations attributable to CNA	-58		-90		-208
Net realized investment gains (losses), pre-tax	37		'		-7
Income tax (expense) benefit on net realized investment gains (losses)	-13		'		2
Net realized investment gains (losses), after tax	24		'		-5
Net income (loss) from continuing operations attributable to CNA	-34		-90		-213
Corporate and Other Non-Core [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Net written premiums	-1	[1]	-1	[1]	2	[1]
Operating Revenues	'		'		'
Net earned premiums	-1		'		1
Net investment income	32		32		32
Other revenues	12		16		6
Total operating revenues	43		48		39
Claims, Benefits and Expenses	'		'		'
Net incurred claims and benefits	191		-16		-3
Policyholders' dividends	'		'		'
Amortization of deferred acquisition costs	'		'		'
Other insurance related expenses	-3		3		6
Other expenses	183		183		170
Total claims, benefits and expenses	371		170		173
Operating income (loss) from continuing operations before income tax	-328		-122		-134
Income tax (expense) benefit on operating income (loss)	118		41		68
Net Operating Income (Loss), After-tax, Attributable to Noncontrolling Interests	'		'		'
Net operating income (loss) from continuing operations attributable to CNA	-210		-81		-66
Net realized investment gains (losses), pre-tax	9		4		-6
Income tax (expense) benefit on net realized investment gains (losses)	-3		-2		3
Net realized investment gains (losses), after tax	6		2		-3
Net income (loss) from continuing operations attributable to CNA	-204		-79		-69
Eliminations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Net written premiums	-2	[1]	-2	[1]	-3	[1]
Operating Revenues	'		'		'
Net earned premiums	-2		-2		-3
Net investment income	'		'		'
Other revenues	-2		-1		'
Total operating revenues	-4		-3		-3
Claims, Benefits and Expenses	'		'		'
Net incurred claims and benefits	'		'		'
Policyholders' dividends	'		'		'
Amortization of deferred acquisition costs	'		'		'
Other insurance related expenses	-2		-2		-3
Other expenses	-2		-1		'
Total claims, benefits and expenses	-4		-3		-3
Operating income (loss) from continuing operations before income tax	'		'		'
Income tax (expense) benefit on operating income (loss)	'		'		'
Net Operating Income (Loss), After-tax, Attributable to Noncontrolling Interests	'		'		'
Net operating income (loss) from continuing operations attributable to CNA	'		'		'
Net realized investment gains (losses), pre-tax	'		'		'
Income tax (expense) benefit on net realized investment gains (losses)	'		'		'
Net realized investment gains (losses), after tax	'		'		'
Net income (loss) from continuing operations attributable to CNA	'		'		'
[1]	(a)Related to business in property and casualty companies only.
[2]	(b)Included from date of acquisition.

Business_Segments_Balance_Shee

Business Segments (Balance Sheet Information) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	$6,088	$6,231
Insurance receivables	2,063	1,983
Deferred acquisition costs	624	598
Goodwill	155	154
Insurance reserves	'	'
Claim and claim adjustment expenses	24,089	24,763
Unearned premiums	3,718	3,610
Future policy benefits	10,471	11,475
Policyholders’ funds	116	157
CNA Specialty [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	546	665
Insurance receivables	775	673
Deferred acquisition costs	318	300
Goodwill	117	117
Insurance reserves	'	'
Claim and claim adjustment expenses	6,689	6,748
Unearned premiums	1,805	1,685
Future policy benefits	'	'
Policyholders’ funds	9	8
CNA Commercial [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	1,075	1,155
Insurance receivables	1,099	1,116
Deferred acquisition costs	257	269
Goodwill	'	'
Insurance reserves	'	'
Claim and claim adjustment expenses	10,649	11,326
Unearned premiums	1,536	1,569
Future policy benefits	'	'
Policyholders’ funds	15	15
Hardy [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	197	294
Insurance receivables	176	181
Deferred acquisition costs	49	29
Goodwill	38	37
Insurance reserves	'	'
Claim and claim adjustment expenses	386	521
Unearned premiums	249	222
Future policy benefits	'	'
Policyholders’ funds	'	'
Life and Group Non-Core [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	1,203	1,273
Insurance receivables	11	9
Deferred acquisition costs	'	'
Goodwill	'	'
Insurance reserves	'	'
Claim and claim adjustment expenses	3,058	3,006
Unearned premiums	128	134
Future policy benefits	10,471	11,475
Policyholders’ funds	92	134
Corporate and Other Non-Core [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	3,067	2,844
Insurance receivables	2	4
Deferred acquisition costs	'	'
Goodwill	'	'
Insurance reserves	'	'
Claim and claim adjustment expenses	3,307	3,162
Unearned premiums	'	'
Future policy benefits	'	'
Policyholders’ funds	'	'
Eliminations [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Reinsurance receivables	'	'
Insurance receivables	'	'
Deferred acquisition costs	'	'
Goodwill	'	'
Insurance reserves	'	'
Claim and claim adjustment expenses	'	'
Unearned premiums	'	'
Future policy benefits	'	'
Policyholders’ funds	'	'

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, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues	$2,613	$2,504	$2,493	$2,503	$2,434	$2,466	$2,246	$2,401	$10,113	$9,547	$8,949
CNA Specialty [Domain]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	3,915	3,742	3,512
International - Specialty [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	239	220	210
Management & Professional Liability [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	2,836	2,723	2,541
Surety [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	490	485	472
Warranty & Alternative Risks [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	350	314	289
CNA Commercial [Domain]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	4,360	4,238	4,073
Commercial Insurance [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	3,230	3,200	2,953
International - Commercial [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	376	369	539
Small Business [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	754	669	581
Hardy [Domain]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	366	123	'
Life & Group Non-Core [Domain]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	1,424	1,395	1,334
Health [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	1,192	1,120	1,093
Life & Annuity [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	232	239	229
Other [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	'	36	12
Corporate and Other Non-Core [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	52	52	33
Eliminations [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	($4)	($3)	($3)

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, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Data [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Revenues	$2,613	$2,504	$2,493	$2,503	$2,434	$2,466	$2,246	$2,401	$10,113	$9,547	$8,949
Net income (loss) attributable to CNA	$221	$272	$194	$250	($9)	$221	$166	$250	$937	$628	$612
Basic earnings (loss) per share attributable to CNA common stockholders	$0.82	$1.01	$0.72	$0.93	'	'	'	'	$3.48	$2.33	$2.27
Diluted earnings (loss) per share attributable to CNA common stockholders	$0.82	$1.01	$0.72	$0.93	'	'	'	'	$3.47	$2.33	$2.27
Basic and diluted earnings (loss) per share attributable to CNA common stockholders	'	'	'	'	($0.03)	$0.82	$0.62	$0.93	'	$2.33	'

Related_Party_Transactions_Nar

Related Party Transactions Narrative (Details) (Loews [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Loews [Member]	'	'	'
Amounts reimbursed to Loews for services provided to the Company	$39	$39	$38
Amounts earned from Loews for insurance premiums	$2	$2	$2

Subsequent_Events_Narrative_De

Subsequent Events (Narrative) (Details) (USD $)	0 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Feb. 10, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Subsequent Event [Line Items]	'	'	'	'	'
Date of subsequent event	10-Feb-14	'	'	'	'
Gross insurance reserves	'	$24,089	$24,763	$24,303	$25,496
Net income (loss) from continuing operations attributable to CNA	'	937	628	613	'
Majority of Run-off Annuity and Pension Deposit Business to be Sold [Member]	'	'	'	'	'
Subsequent Event [Line Items]	'	'	'	'	'
Gross insurance reserves	'	3,400	'	'	'
Net income (loss) from continuing operations attributable to CNA	'	31	8	-124	'
Sale of Subsidiary Gain (Loss) [Member] | Majority of Run-off Annuity and Pension Deposit Business to be Sold [Member]	'	'	'	'	'
Subsequent Event [Line Items]	'	'	'	'	'
Expected impairment loss on sale, after-tax	220	'	'	'	'

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, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues	'	'	'	'	'	'	'	'	'	'	'
Net realized investment gains (losses)	'	'	'	'	'	'	'	'	$31	$63	($2)
Other revenues	'	'	'	'	'	'	'	'	361	320	294
Total revenues	2,613	2,504	2,493	2,503	2,434	2,466	2,246	2,401	10,113	9,547	8,949
Expenses	'	'	'	'	'	'	'	'	'	'	'
Interest	'	'	'	'	'	'	'	'	166	170	175
Income tax expense (benefit)	'	'	'	'	'	'	'	'	376	244	242
Net income (loss) attributable to CNA	221	272	194	250	-9	221	166	250	937	628	612
Total comprehensive income (loss) attributable to CNA	'	'	'	'	'	'	'	'	548	979	755
Parent Company [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	'	'	'
Net investment income	'	'	'	'	'	'	'	'	1	1	1
Net realized investment gains (losses)	'	'	'	'	'	'	'	'	4	4	-9
Other revenues	'	'	'	'	'	'	'	'	'	9	40
Total revenues	'	'	'	'	'	'	'	'	5	14	32
Expenses	'	'	'	'	'	'	'	'	'	'	'
Administrative and general	'	'	'	'	'	'	'	'	-7	1	3
Interest	'	'	'	'	'	'	'	'	165	164	167
Total expenses	'	'	'	'	'	'	'	'	158	165	170
Income (loss) from operations before income taxes and equity in net income of subsidiaries	'	'	'	'	'	'	'	'	-153	-151	-138
Income tax expense (benefit)	'	'	'	'	'	'	'	'	-22	-144	-46
Income (loss) before equity in net income (loss) of subsidiaries	'	'	'	'	'	'	'	'	-131	-7	-92
Equity in net income of subsidiaries	'	'	'	'	'	'	'	'	1,068	635	704
Net income (loss) attributable to CNA	'	'	'	'	'	'	'	'	937	628	612
Equity in other comprehensive income of subsidiaries	'	'	'	'	'	'	'	'	-389	351	143
Total comprehensive income (loss) attributable to CNA	'	'	'	'	'	'	'	'	$548	$979	$755

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, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Assets	'	'	'	'
Cash	$195	$156	$75	$77
Fixed maturity securities available-for-sale, at fair value (amortized cost of $1 and $2)	41,197	42,604	'	'
Short term investments	1,407	1,832	'	'
Other assets	969	773	'	'
Total assets	57,194	58,522	'	'
Liabilities	'	'	'	'
Short term debt	549	13	'	'
Long term debt	2,011	2,557	'	'
Other liabilities	3,408	3,321	'	'
Total liabilities	44,543	46,208	'	'
Stockholders' Equity	'	'	'	'
Common stock ($2.50 par value; 500,000,000 shares authorized; 273,040,243 shares issued; 269,717,583 and 269,399,390 shares outstanding)	683	683	'	'
Additional paid-in capital	2,145	2,146	'	'
Retained earnings	9,495	8,774	'	'
Accumulated other comprehensive income (loss)	442	831	'	'
Treasury stock (3,322,660 and 3,640,853 shares), at cost	-91	-99	'	'
Notes receivable for the issuance of common stock	-23	-21	'	'
Total stockholders’ equity	12,651	12,314	'	'
Total liabilities and stockholders' equity	57,194	58,522	'	'
Balance Sheet Parenthetical	'	'	'	'
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	269,717,583	269,399,390	'	'
Treasury stock, shares	3,322,660	3,640,853	'	'
Parent Company [Member]	'	'	'	'
Assets	'	'	'	'
Investment in subsidiaries	14,708	14,427	'	'
Cash	1	'	'	'
Fixed maturity securities available-for-sale, at fair value (amortized cost of $1 and $2)	1	2	'	'
Short term investments	505	448	'	'
Amounts due from subsidiaries	3	2	'	'
Other assets	3	5	'	'
Total assets	15,221	14,884	'	'
Liabilities	'	'	'	'
Short term debt	549	3	'	'
Long term debt	1,981	2,527	'	'
Other liabilities	40	40	'	'
Total liabilities	2,570	2,570	'	'
Stockholders' Equity	'	'	'	'
Common stock ($2.50 par value; 500,000,000 shares authorized; 273,040,243 shares issued; 269,717,583 and 269,399,390 shares outstanding)	683	683	'	'
Additional paid-in capital	2,145	2,146	'	'
Retained earnings	9,495	8,774	'	'
Accumulated other comprehensive income (loss)	442	831	'	'
Treasury stock (3,322,660 and 3,640,853 shares), at cost	-91	-99	'	'
Notes receivable for the issuance of common stock	-23	-21	'	'
Total stockholders’ equity	12,651	12,314	'	'
Total liabilities and stockholders' equity	15,221	14,884	'	'
Balance Sheet Parenthetical	'	'	'	'
Marketable securities fixed maturities available-for-sale at amortized cost basis	$1	$2	'	'
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	'	269,399,390	'	'
Treasury stock, shares	'	3,640,853	'	'

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, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flows from Operating Activities	'	'	'
Net income (loss)	$937	$628	$612
Adjustments to reconcile net income (loss) to net cash flows provided (used) by operating activities:	'	'	'
Net realized investment (gains) losses	-31	-63	2
Other, net	10	14	10
Total adjustments	267	622	1,076
Net cash flows provided (used) by operating activities-total	1,204	1,250	1,702
Cash Flows from Investing Activities	'	'	'
Change in short term investments	425	-7	566
Other, net	11	16	1
Net cash flows provided (used) by investing activities-total	-898	-934	-1,060
Cash Flows from Financing Activities	'	'	'
Dividends paid to common stockholders	-216	-162	-108
Proceeds from the issuance of debt	'	'	396
Repayment of debt	-13	-70	-451
Stock options exercised	2	1	2
Other, net	-37	-8	-8
Net cash flows provided (used) by financing activities-total	-264	-239	-644
Net change in cash	39	81	-2
Cash, beginning of year	156	75	77
Cash, end of year	195	156	75
Parent Company [Member]	'	'	'
Cash Flows from Operating Activities	'	'	'
Net income (loss)	937	628	612
Adjustments to reconcile net income (loss) to net cash flows provided (used) by operating activities:	'	'	'
Equity in net income (loss) of subsidiaries	-1,068	-635	-704
Dividends received from subsidiaries	400	450	'
Net realized investment (gains) losses	-4	-4	9
Other, net	8	19	55
Total adjustments	-664	-170	-640
Net cash flows provided (used) by operating activities-total	273	458	-28
Cash Flows from Investing Activities	'	'	'
Proceeds from fixed maturity securities	1	1	1
Change in short term investments	-57	-156	-77
Capital contributions to subsidiaries	-12	-399	-38
Return of capital from subsidiaries	'	'	6
Repayment of surplus note by subsidiary	'	250	250
Other, net	4	4	1
Net cash flows provided (used) by investing activities-total	-64	-300	143
Cash Flows from Financing Activities	'	'	'
Dividends paid to common stockholders	-216	-162	-108
Proceeds from the issuance of debt	'	'	396
Repayment of debt	-3	'	-409
Stock options exercised	2	1	5
Other, net	9	3	1
Net cash flows provided (used) by financing activities-total	-208	-158	-115
Net change in cash	1	'	'
Cash, beginning of year	'	'	'
Cash, end of year	$1	'	'

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, 2013
In Millions, unless otherwise specified
Aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third party loans	$702
Recorded liabilities related to indemnification agreements	7
Parent Company [Member]	'
Percentage of CNAF common stock outstanding currently held by Loews	90.00%
Aggregate amount of quantifiable indemnification agreements in effect for sales of business entities, assets and third party loans	255
Recorded liabilities related to indemnification agreements	'
Maximum exposure SSAs	$2,000

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, 2013		Dec. 31, 2012		Dec. 31, 2011
Allowance for doubtful accounts, insurance and reinsurance receivables [Member]	'		'		'
Movement in valuation allowances and reserves [Roll Forward]	'		'		'
Balance at beginning of period	$174		$203		$285
Charged to costs and expenses	-6		-23		-55
Charged to other accounts	-3	[1]	5	[1]	'	[1]
Deductions	-10		-11		-27
Balance at end of period	$155		$174		$203
[1]	Amount includes effects of foreign currency translation.

Schedule_VI_Supplemental_Infor2

Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations (Details) (Consolidated Property and Casualty Insurance Entity [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidated Property and Casualty Insurance Entity [Member]	'	'	'
Deferred acquisition costs	$624	$598	'
Reserves for unpaid claim and claim adjustment expenses	24,015	24,696	'
Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.0% to 9.7%)	1,586	1,850	'
Unearned Premiums	3,718	3,610	'
Net written premiums	7,348	6,964	6,798
Net earned premiums	7,271	6,881	6,603
Net investment income	2,240	2,074	1,845
Incurred claim and claim adjustment expenses related to current year	5,113	5,266	4,901
Incurred claim and claim adjustment expenses related to prior years	-115	-180	-429
Amortization of deferred acquisition costs	1,362	1,274	1,176
Paid claim and claim adjustment expenses	$5,566	$5,257	$4,499
Supplemental Information Parenthetical	'	'	'
Minimum interest rate in discount range	3.00%	'	'
Maximum interest rate in discount range	9.70%	'	'