Chubb Limited (CB) 10-K 28 Feb 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2013	Feb. 14, 2014	Jun. 28, 2013
Document Documentand Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'ACE	'	'
Entity Registrant Name	'ACE Ltd	'	'
Entity Central Index Key	'0000896159	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	336,657,376	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Public Float	'	'	$30

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Assets	'	'
Fixed maturities available for sale, at fair value (amortized cost - $48,406 and $44,666) (includes hybrid financial instruments of $302 and $309)	$49,254	$47,306
Fixed maturities held to maturity, at amortized cost (fair value – $6,263 and $7,633)	6,098	7,270
Equity securities, at fair value (cost – $841 and $707)	837	744
Short-term investments, at fair value and amortized cost	1,763	2,228
Other investments (cost – $2,671 and $2,465)	2,976	2,716
Total investments	60,928	60,264
Cash	579	615
Securities lending collateral	1,632	1,791
Accrued investment income	556	552
Insurance and reinsurance balances receivable	5,026	4,147
Reinsurance recoverable on losses and loss expenses	11,227	12,078
Reinsurance recoverable on policy benefits	218	241
Deferred policy acquisition costs	2,313	1,873
Value of business acquired	536	614
Goodwill and other intangible assets	5,404	4,975
Prepaid reinsurance premiums	1,675	1,617
Deferred tax assets	616	453
Investments in partially-owned insurance companies (cost – $467 and $451)	470	454
Other assets	3,330	2,871
Total assets	94,510	92,545
Liabilities	'	'
Unpaid losses and loss expenses	37,443	37,946
Unearned premiums	7,539	6,864
Future policy benefits	4,615	4,470
Insurance and reinsurance balances payable	3,628	3,472
Securities lending payable	1,633	1,795
Accounts payable, accrued expenses, and other liabilities	4,810	5,397
Short-term debt	1,901	1,401
Long-term debt	3,807	3,360
Trust preferred securities	309	309
Total liabilities	65,685	65,014
Shareholders' equity	'	'
Common Shares (CHF 27.04 and CHF 28.89 par value; 342,832,412 shares issued; 339,793,935 and 340,321,534 shares outstanding)	8,899	9,591
Common Shares in treasury (3,038,477 and 2,510,878 shares)	-255	-159
Additional paid-in capital	5,238	5,179
Retained earnings	13,791	10,033
Accumulated other comprehensive income (AOCI)	1,152	2,887
Total shareholders’ equity	28,825	27,531
Total liabilities and shareholders’ equity	$94,510	$92,545

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical)	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2012
In Millions, except Share data, unless otherwise specified	USD ($)	CHF	USD ($)	CHF
Statement of Financial Position [Abstract]	'	'	'	'
Fixed maturities available for sale, at amortized cost	$48,406	'	$44,666	'
Fixed maturities available for sale, hybrid financial instruments	302	'	309	'
Fixed maturities held to maturity, at fair value	6,263	'	7,633	'
Equity securities, at cost	841	'	707	'
Other investments, cost	2,671	'	2,465	'
Investments in partially-owned insurance companies, cost	$467	'	$451	'
Common Shares, par value	'	27.04	'	28.89
Common Shares, shares issued	342,832,412	342,832,412	342,832,412	342,832,412
Common Shares, shares outstanding	339,793,935	339,793,935	340,321,534	340,321,534
Common Shares in treasury, shares	3,038,477	3,038,477	2,510,878	2,510,878

Consolidated_Statements_Of_Ope

Consolidated Statements Of Operations and Comprehensive Income (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues	'	'	'
Net premiums written	$17,025	$16,075	$15,372
(Increase) decrease in unearned premiums	-412	-398	15
Net premiums earned	16,613	15,677	15,387
Net investment income	2,144	2,181	2,242
Net realized gains (losses):	'	'	'
Other-than-temporary impairment (OTTI) losses gross	-22	-38	-65
Portion of OTTI losses recognized in other comprehensive income (OCI)	0	1	15
Net OTTI losses recognized in income	-22	-37	-50
Net realized gains (losses) excluding OTTI losses	526	115	-745
Total net realized gains (losses)	504	78	-795
Total revenues	19,261	17,936	16,834
Expenses	'	'	'
Losses and loss expenses	9,348	9,653	9,520
Policy benefits	515	521	401
Policy acquisition costs	2,659	2,446	2,472
Administrative expenses	2,211	2,096	2,068
Interest expense	275	250	250
Other (income) expense	15	-6	81
Total expenses	15,023	14,960	14,792
Income before income tax	4,238	2,976	2,042
Income tax expense	480	270	502
Net income	3,758	2,706	1,540
Other comprehensive income (loss)	'	'	'
Unrealized appreciation (depreciation)	-1,762	1,350	646
Reclassification adjustment for net realized gains included in net income	-105	-234	-173
Other comprehensive income (loss)after reclassification for net realized gains included in net income	-1,867	1,116	473
Change in:	'	'	'
Cumulative translation adjustment	-339	116	-5
Pension liability	0	-35	8
Other comprehensive income (loss), before income tax	-2,206	1,197	476
Income tax benefit (expense) related to OCI items	471	-221	-159
Other comprehensive income (loss)	-1,735	976	317
Comprehensive income	$2,023	$3,682	$1,857
Earnings per share	'	'	'
Basic earnings per share	$11.02	$7.96	$4.55
Diluted earnings per share	$10.92	$7.89	$4.52

Recovered_Sheet1

Consolidated Statements of Operations and Comprehensive Income (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2013
Income tax expense (benefit)	$480,000,000
Net realized gains (losses)	504,000,000
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net unrealized appreciation on investments	'
Income tax expense (benefit)	17,000,000
Net realized gains (losses)	$105,000,000

Consolidated_Statements_Of_Sha

Consolidated Statements Of Shareholders' Equity (USD $)	Total	Common Shares	Common Shares in Treasury	Additional Paid-in Capital	Retained Earnings	Deferred Compensation Obligation	Accumulated Other Comprehensive Income	Net unrealized appreciation on investments	Cumulative Translation Adjustment	Accumulated Defined Benefit Plans Adjustment [Member]	Common Shares Issued To Employee Trust
In Millions
Balance – beginning of year at Dec. 31, 2010	'	$10,161	($330)	$5,623	$5,787	$2	'	$1,399	$262	($67)	($2)
Net shares redeemed under employee share-based compensation plans	'	'	'	-104	'	'	'	'	'	'	'
Exercise of stock options	'	47	'	16	'	'	'	'	'	'	'
Dividends declared on Common Shares-par value reduction	'	-113	'	'	'	'	'	'	'	'	'
Common Shares repurchased	'	'	-132	'	'	'	'	'	'	'	'
Common Shares issued in treasury, net of net shares redeemed under employee share-based compensation plans	'	'	135	'	'	'	'	'	'	'	'
Share-based compensation expense and other	'	'	'	139	'	'	'	'	'	'	'
Tax benefit on share-based compensation expense	'	'	'	6	'	'	'	'	'	'	'
Net income	1,540	'	'	'	1,540	'	'	'	'	'	'
Net income at Jan. 01, 2011 (Scenario, Previously Reported)	1,540	'	'	'	'	'	'	'	'	'	'
Funding of dividends declared from Additional paid-in capital	'	'	'	354	-354	'	'	'	'	'	'
Dividends declared on Common Shares	'	'	'	'	-354	'	'	'	'	'	'
Decrease to obligation	'	'	'	'	'	-2	'	'	'	'	'
Change in year, net of income tax benefit (expense) of $408, $(198), and $(157)	'	'	'	'	'	'	'	316	'	'	'
Change in year, net of income tax benefit (expense) of $63, $(35) and $1	'	'	'	'	'	'	'	'	-4	'	'
Movement In Common Shares Issued To Employee Trust	'	'	'	'	'	'	'	'	'	'	2
Balance - end of year at Dec. 31, 2011	24,332	10,095	-327	5,326	7,327	0	1,911	1,715	258	-62	0
Net shares redeemed under employee share-based compensation plans	'	'	'	-93	'	'	'	'	'	'	'
Exercise of stock options	'	0	'	-7	'	'	'	'	'	'	'
Dividends declared on Common Shares-par value reduction	'	-504	'	'	'	'	'	'	'	'	'
Common Shares repurchased	'	'	-7	'	'	'	'	'	'	'	'
Common Shares issued in treasury, net of net shares redeemed under employee share-based compensation plans	'	'	175	'	'	'	'	'	'	'	'
Share-based compensation expense and other	'	'	'	135	'	'	'	'	'	'	'
Tax benefit on share-based compensation expense	'	'	'	18	'	'	'	'	'	'	'
Net income	2,706	'	'	'	2,706	'	'	'	'	'	'
Net income at Jan. 01, 2012 (Scenario, Previously Reported)	2,706	'	'	'	'	'	'	'	'	'	'
Funding of dividends declared from Additional paid-in capital	'	'	'	-200	200	'	'	'	'	'	'
Dividends declared on Common Shares	'	'	'	'	-200	'	'	'	'	'	'
Decrease to obligation	'	'	'	'	'	0	'	'	'	'	'
Change in year, net of income tax benefit (expense) of $408, $(198), and $(157)	'	'	'	'	'	'	'	918	'	'	'
Change in year, net of income tax benefit (expense) of $63, $(35) and $1	'	'	'	'	'	'	'	'	81	'	'
Movement In Common Shares Issued To Employee Trust	'	'	'	'	'	'	'	'	'	'	0
Balance - end of year at Dec. 31, 2012 (Scenario, Previously Reported)	27,531	'	'	'	'	'	'	'	'	'	'
Balance - end of year at Dec. 31, 2012	27,531	9,591	-159	5,179	10,033	0	2,887	2,633	339	-85	0
Net shares redeemed under employee share-based compensation plans	'	'	'	-126	'	'	'	'	'	'	'
Exercise of stock options	'	0	'	-42	'	'	'	'	'	'	'
Dividends declared on Common Shares-par value reduction	'	-692	'	'	'	'	'	'	'	'	'
Common Shares repurchased	'	'	-290	'	'	'	'	'	'	'	'
Common Shares issued in treasury, net of net shares redeemed under employee share-based compensation plans	'	'	194	'	'	'	'	'	'	'	'
Share-based compensation expense and other	'	'	'	191	'	'	'	'	'	'	'
Tax benefit on share-based compensation expense	'	'	'	36	'	'	'	'	'	'	'
Net income	3,758	'	'	'	3,758	'	'	'	'	'	'
Funding of dividends declared from Additional paid-in capital	'	'	'	0	'	'	'	'	'	'	'
Dividends declared on Common Shares	'	'	'	'	'	'	'	'	'	'	'
Decrease to obligation	'	'	'	'	'	0	'	'	'	'	'
Change in year, before reclassification from AOCI, net of income tax benefit of $391	'	'	'	'	'	'	'	-1,371	'	'	'
Amounts reclassified from AOCI, net of income tax benefit of $17	'	'	'	'	'	'	'	-88	'	'	'
Change in year, net of income tax benefit (expense) of $408, $(198), and $(157)	'	'	'	'	'	'	'	-1,459	-276	'	'
Change in year, net of income tax benefit (expense) of $63, $(35) and $1	'	'	'	'	'	'	'	'	'	0	'
Movement In Common Shares Issued To Employee Trust	'	'	'	'	'	'	'	'	'	'	0
Balance - end of year at Dec. 31, 2013	$28,825	$8,899	($255)	$5,238	$13,791	$0	$1,152	$1,174	$63	($85)	$0

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	$3,758	$2,706		$1,540
Adjustments to reconcile net income to net cash flows from operating activities	'	'		'
Net realized (gains) losses	-504	-78		795
Amortization of premiums/discounts on fixed maturities	268	220		152
Deferred income taxes	240	-7		15
Unpaid losses and loss expenses	-365	203		43
Unearned premiums	402	522		9
Future policy benefits	191	158		78
Insurance and reinsurance balances payable	176	-151		216
Accounts payable, accrued expenses, and other liabilities	37	-42		39
Income taxes payable	-45	-167		39
Insurance and reinsurance balances receivable	-624	335		-217
Reinsurance recoverable on losses and loss expenses	787	372		531
Reinsurance recoverable on policy benefits	23	52		25
Deferred policy acquisition costs	-503	-340		-122
Prepaid reinsurance premiums	-31	-123		-34
Other	212	335		361
Net cash flows from operating activities	4,022	3,995		3,470
Cash flows from investing activities	'	'		'
Purchases of fixed maturities available for sale	-21,340	-23,572		-23,523
Purchases of to be announced mortgage-backed securities	-58	-389		-755
Purchases of fixed maturities held to maturity	-447	-388		-340
Purchases of equity securities	-264	-135		-309
Sales of fixed maturities available for sale	10,355	14,321		17,176
Sales of to be announced mortgage-backed securities	58	448		795
Sales of equity securities	142	119		376
Maturities and redemptions of fixed maturities available for sale	6,941	5,523		3,720
Maturities and redemptions of fixed maturities held to maturity	1,488	1,451		1,279
Net change in short-term investments	524	117		-300
Net derivative instruments settlements	-471	-281		-67
Acquisition of subsidiaries (net of cash acquired of $38, $8, and $91)	-977	-98		-606
Other	-393	-555		-482
Net cash flows used for investing activities	-4,442	-3,439		-3,036
Cash flows from financing activities	'	'		'
Dividends paid on Common Shares	-517	-815		-459
Common Shares repurchased	-287	-11		-195
Proceeds from issuance of long-term debt	947	'		'
Proceeds from issuance of short-term debt	2,572	2,933		5,238
Repayment of short-term debt	-2,572	-2,783		-5,288
Proceeds from share-based compensation plans, including windfall tax benefits	135	126		139
Other	113	'		'
Net cash flows from (used for) financing activities	391	-550		-565
Effect of foreign currency rate changes on cash and cash equivalents	-7	-5		-27
Net increase (decrease) in cash	-36	1		-158
Cash – beginning of year	615	614	[1]	772
Cash – end of year	579	615		614	[1]
Supplemental cash flow information	'	'		'
Taxes paid	218	438		460
Interest paid	$253	$240		$234
[1]	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

Consolidated_Statements_Of_Cas1

Consolidated Statements Of Cash Flows (Parenthetical) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010
Statement of Cash Flows [Abstract]	'	'	'
Acquisition of subsidiaries, cash acquired	$38	$8	$91

Summary_of_significant_account

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Summary of significant accounting policies	'
	Summary of significant accounting policies
	a) Basis of presentation
	ACE Limited is a holding company incorporated in Zurich, Switzerland. ACE Limited, through its subsidiaries, provides a broad range of insurance and reinsurance products to insureds worldwide. ACE operates through five business segments: Insurance – North American P&C, Insurance – North American Agriculture, Insurance – Overseas General, Global Reinsurance, and Life. Refer to Note 15 for additional information.
	The accompanying consolidated financial statements, which include the accounts of ACE Limited and its subsidiaries (collectively, ACE, we, us, or our), have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and, in the opinion of management, reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of the results and financial position for such periods. All significant intercompany accounts and transactions have been eliminated.
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Amounts included in the consolidated financial statements reflect our best estimates and assumptions; actual amounts could differ materially from these estimates. ACE's principal estimates include:
	•	unpaid loss and loss expense reserves, including long-tail asbestos and environmental (A&E) reserves;
	•	future policy benefits reserves;
	•	the valuation of value of business acquired (VOBA) and amortization of deferred policy acquisition costs and VOBA;
	•	reinsurance recoverable, including a provision for uncollectible reinsurance;
	•	the assessment of risk transfer for certain structured insurance and reinsurance contracts;
	•	the valuation of the investment portfolio and assessment of OTTI;
	•	the valuation of deferred tax assets;
	•	the valuation of derivative instruments related to guaranteed living benefits (GLB); and
	•	the valuation of goodwill.
	b) Premiums
	Premiums are generally recognized as written upon inception of the policy. For multi-year policies for which premiums written are payable in annual installments, only the current annual premium is included as written at policy inception due to the ability of the insured/reinsured to commute or cancel coverage within the policy term. The remaining annual premiums are included as written at each successive anniversary date within the multi-year term.
	For property and casualty (P&C) insurance and reinsurance products, premiums written are primarily earned on a pro-rata basis over the policy terms to which they relate. Unearned premiums represent the portion of premiums written applicable to the unexpired portion of the policies in force. For retrospectively-rated policies, written premiums are adjusted to reflect expected ultimate premiums consistent with changes to reported losses, or other measures of exposure as stated in the policy, and earned over the policy coverage period. For retrospectively-rated multi-year policies, premiums recognized in the current period are computed, using a with-and-without method, as the difference between the ceding enterprise's total contract costs before and after the experience under the contract at the reporting date. Accordingly, for retrospectively-rated multi-year policies, additional premiums are generally written and earned when losses are incurred.
	Mandatory reinstatement premiums assessed on reinsurance policies are earned in the period of the loss event that gave rise to the reinstatement premiums.  All remaining unearned premiums are recognized over the remaining coverage period.
	Premiums from long-duration contracts such as certain traditional term life, whole life, endowment, and long-duration personal accident and health (A&H) policies are generally recognized as revenue when due from policyholders. Traditional life policies include those contracts with fixed and guaranteed premiums and benefits. Benefits and expenses are matched with income to result in the recognition of profit over the life of the contracts.
	Retroactive loss portfolio transfer (LPT) contracts in which the insured loss events occurred prior to contract inception are evaluated to determine whether they meet criteria for reinsurance accounting. If reinsurance accounting is appropriate, written premiums are fully earned and corresponding losses and loss expenses recognized at contract inception. These contracts can cause significant variances in gross premiums written, net premiums written, net premiums earned, and net incurred losses in the years in which they are written. Reinsurance contracts sold not meeting criteria for reinsurance accounting are recorded using the deposit method as described below in Note 1 k).
	Reinsurance premiums assumed are based on information provided by ceding companies supplemented by our own estimates of premium when we have not received ceding company reports. Estimates are reviewed and adjustments are recorded in the period in which they are determined. Premiums are earned over the coverage terms of the related reinsurance contracts and range from one to three years.
	c) Deferred policy acquisition costs and value of business acquired
	Policy acquisition costs consist of commissions (direct and ceded), premium taxes, and certain underwriting costs related directly to the successful acquisition of new or renewal insurance contracts. A VOBA intangible asset is established upon the acquisition of blocks of long-duration contracts in a business combination and represents the present value of estimated net cash flows for the contracts in force at the acquisition date. Acquisition costs and VOBA, collectively policy acquisition costs, are deferred and amortized. Amortization is recorded in Policy acquisition costs in the consolidated statements of operations. Policy acquisition costs on P&C contracts are generally amortized ratably over the period in which premiums are earned. Policy acquisition costs on traditional long-duration contracts are amortized over the estimated life of the contracts, generally in proportion to premium revenue recognized. For non-traditional long-duration contracts, we amortize policy acquisition costs over the expected life of the contracts in proportion to expected gross profits.  The effect of changes in estimates of expected gross profits is reflected in the period the estimates are revised. Policy acquisition costs are reviewed to determine if they are recoverable from future income, including investment income. Unrecoverable policy acquisition costs are expensed in the period identified.
	Advertising costs are expensed as incurred except for direct-response campaigns that qualify for cost deferral, principally related to A&H business produced by the Insurance – Overseas General segment, which are deferred and recognized as a component of policy acquisition costs. For individual direct-response marketing campaigns that we can demonstrate have specifically resulted in incremental sales to customers and such sales have probable future economic benefits, incremental costs directly related to the marketing campaigns are capitalized. Deferred marketing costs are reviewed regularly for recoverability from future income, including investment income, and amortized in proportion to premium revenue recognized, primarily over a ten-year period, the expected economic future benefit period. The expected future benefit period is evaluated periodically based on historical results and adjusted prospectively. The amount of deferred marketing costs reported in Deferred policy acquisition costs in the consolidated balance sheets was $307 million and $274 million at December 31, 2013 and 2012, respectively. Amortization expense for deferred marketing costs was $128 million, $119 million, and $128 million for the years ended December 31, 2013, 2012, and 2011, respectively (2012 disclosure amount adjusted to present deferred marketing amortization costs in a manner consistent with the 2013 amount).
	d) Reinsurance
	ACE assumes and cedes reinsurance with other insurance companies to provide greater diversification of business and minimize the net loss potential arising from large risks. Ceded reinsurance contracts do not relieve ACE of its primary obligation to policyholders.
	For both ceded and assumed reinsurance, risk transfer requirements must be met in order to account for a contract as reinsurance, principally resulting in the recognition of cash flows under the contract as premiums and losses. To meet risk transfer requirements, a reinsurance contract must include insurance risk, consisting of both underwriting and timing risk, and a reasonable possibility of a significant loss for the assuming entity. To assess risk transfer for certain contracts, ACE generally develops expected discounted cash flow analyses at contract inception. Deposit accounting is used for contracts that do not meet risk transfer requirements. Deposit accounting requires that consideration received or paid be recorded in the balance sheet as opposed to recording premiums written or losses incurred in the statement of operations. Non-refundable fees on deposit contracts are earned based on the terms of the contract described below in Note 1 k).
	Reinsurance recoverable includes balances due from reinsurance companies for paid and unpaid losses and loss expenses and policy benefits that will be recovered from reinsurers, based on contracts in force. The method for determining the reinsurance recoverable on unpaid losses and loss expenses incurred but not reported (IBNR) involves actuarial estimates consistent with those used to establish the associated liability for unpaid losses and loss expenses as well as a determination of ACE's ability to cede unpaid losses and loss expenses under the terms of the reinsurance agreement.
	Reinsurance recoverable is presented net of a provision for uncollectible reinsurance determined based upon a review of the financial condition of reinsurers and other factors. The provision for uncollectible reinsurance is based on an estimate of the reinsurance recoverable balance that will ultimately be unrecoverable due to reinsurer insolvency, a contractual dispute, or any other reason. The valuation of this provision includes several judgments including certain aspects of the allocation of reinsurance recoverable on IBNR claims by reinsurer and a default analysis to estimate uncollectible reinsurance. The primary components of the default analysis are reinsurance recoverable balances by reinsurer, net of collateral, and default factors used to determine the portion of a reinsurer's balance deemed uncollectible. The definition of collateral for this purpose requires some judgment and is generally limited to assets held in an ACE-only beneficiary trust, letters of credit, and liabilities held with the same legal entity for which ACE believes there is a contractual right of offset. The determination of the default factor is principally based on the financial strength rating of the reinsurer. Default factors require considerable judgment and are determined using the current financial strength rating, or rating equivalent, of each reinsurer as well as other key considerations and assumptions. The more significant considerations include, but are not necessarily limited to, the following:
	•	For reinsurers that maintain a financial strength rating from a major rating agency, and for which recoverable balances are considered representative of the larger population (i.e., default probabilities are consistent with similarly rated reinsurers and payment durations conform to averages), the financial rating is based on a published source and the default factor is based on published default statistics of a major rating agency applicable to the reinsurer's particular rating class. When a recoverable is expected to be paid in a brief period of time by a highly rated reinsurer, such as certain property catastrophe claims, a default factor may not be applied;
	•	For balances recoverable from reinsurers that are both unrated by a major rating agency and for which management is unable to determine a credible rating equivalent based on a parent, affiliate, or peer company, we determine a rating equivalent based on an analysis of the reinsurer that considers an assessment of the creditworthiness of the particular entity, industry benchmarks, or other factors as considered appropriate. We then apply the applicable default factor for that rating class. For balances recoverable from unrated reinsurers for which the ceded reserve is below a certain threshold, we generally apply a default factor of 34 percent, consistent with published statistics of a major rating agency;
	•	For balances recoverable from reinsurers that are either insolvent or under regulatory supervision, we establish a default factor and resulting provision for uncollectible reinsurance based on reinsurer-specific facts and circumstances. Upon initial notification of an insolvency, we generally recognize an expense for a substantial portion of all balances outstanding, net of collateral, through a combination of write-offs of recoverable balances and increases to the provision for uncollectible reinsurance. When regulatory action is taken on a reinsurer, we generally recognize a default factor by estimating an expected recovery on all balances outstanding, net of collateral. When sufficient credible information becomes available, we adjust the provision for uncollectible reinsurance by establishing a default factor pursuant to information received; and
	•	For other recoverables, management determines the provision for uncollectible reinsurance based on the specific facts and circumstances.
	The methods used to determine the reinsurance recoverable balance and related provision for uncollectible reinsurance are regularly reviewed and updated, and any resulting adjustments are reflected in earnings in the period identified.
	Prepaid reinsurance premiums represent the portion of premiums ceded to reinsurers applicable to the unexpired coverage terms of the reinsurance contracts in force.
	The value of reinsurance business assumed of $27 million and $32 million at December 31, 2013 and 2012, respectively, included in Other assets in the accompanying consolidated balance sheets, represents the excess of estimated ultimate value of the liabilities assumed under retroactive reinsurance contracts over consideration received. The value of reinsurance business assumed is amortized and recorded to losses and loss expenses based on the payment pattern of the losses assumed and ranges between 9 and 40 years. The unamortized value is reviewed regularly to determine if it is recoverable based upon the terms of the contract, estimated losses and loss expenses, and anticipated investment income. Unrecoverable amounts are expensed in the period identified.
	e) Investments
	Fixed maturities are classified as either available for sale or held to maturity. The available for sale portfolio is reported at fair value. The held to maturity portfolio includes securities for which we have the ability and intent to hold to maturity or redemption and is reported at amortized cost. Equity securities are classified as available for sale and are recorded at fair value. Short-term investments comprise securities due to mature within one year of the date of purchase and are recorded at fair value which typically approximates cost. Short-term investments include certain cash and cash equivalents, which are part of investment portfolios under the management of external investment managers.
	Other investments principally comprise life insurance policies, policy loans, trading securities, other direct equity investments, investment funds, and limited partnerships.
	•	Life insurance policies are carried at policy cash surrender value.
	•	Policy loans are carried at outstanding balance.
	•	Trading securities are recorded on a trade date basis and carried at fair value. Unrealized gains and losses on trading securities are reflected in Net income.
	•	Other investments over which ACE can exercise significant influence are accounted for using the equity method.
	•	All other investments over which ACE cannot exercise significant influence are carried at fair value with changes in fair value recognized through OCI. For these investments, investment income and realized gains are recognized as related distributions are received.
	•	Partially-owned investment companies comprise entities in which we hold an ownership interest in excess of three percent. These investments as well as ACE's investments in investment funds where our ownership interest is in excess of three percent are accounted for under the equity method because ACE exerts significant influence. These investments apply investment company accounting to determine operating results, and ACE retains the investment company accounting in applying the equity method. This means that investment income, realized gains or losses, and unrealized gains or losses are included in the portion of equity earnings reflected in Other (income) expense.
	Investments in partially-owned insurance companies primarily represent direct investments in which ACE has significant influence and, as such, meet the requirements for equity accounting. We report our share of the net income or loss of the partially-owned insurance companies in Other (income) expense. Investments in partially-owned insurance companies over which ACE does not exert significant influence are carried at fair value with changes in fair value recognized through OCI.
	Realized gains or losses on sales of investments are determined on a first-in, first-out basis. Unrealized appreciation (depreciation) on investments is included as a separate component of AOCI in Shareholders' equity. We regularly review our investments for OTTI. Refer to Note 3 for additional information.
	With respect to securities where the decline in value is determined to be temporary and the security's value is not written down, a subsequent decision may be made to sell that security and realize a loss. Subsequent decisions on security sales are the result of changing or unforeseen facts and circumstances (i.e., arising from a large insured loss such as a catastrophe), deterioration of the creditworthiness of the issuer or its industry, or changes in regulatory requirements. We believe that subsequent decisions to sell such securities are consistent with the classification of the majority of the portfolio as available for sale.
	We use derivative instruments including futures, options, swaps, and foreign currency forward contracts for the purpose of managing certain investment portfolio risks and exposures. Refer to Note 10 for additional information. Derivatives are reported at fair value and are recorded in the accompanying consolidated balance sheets in either Accounts payable, accrued expenses, and other liabilities or Other assets with changes in fair value included in Net realized gains (losses) in the consolidated statements of operations. Collateral held by brokers equal to a percentage of the total value of open futures contracts is included in the investment portfolio.
	Net investment income includes interest and dividend income and amortization of fixed maturity market premiums and discounts and is net of investment management and custody fees. For mortgage-backed securities, and any other holdings for which there is a prepayment risk, prepayment assumptions are evaluated and revised as necessary. Any adjustments required due to the resultant change in effective yields and maturities are recognized prospectively. Prepayment fees or call premiums that are only payable when a security is called prior to its maturity are earned when received and reflected in Net investment income.
	ACE participates in a securities lending program operated by a third-party banking institution whereby certain assets are loaned to qualified borrowers and from which we earn an incremental return. Borrowers provide collateral, in the form of either cash or approved securities, of 102 percent of the fair value of the loaned securities.  Each security loan is deemed to be an overnight transaction.  Cash collateral is invested in a collateral pool which is managed by the banking institution.  The collateral pool is subject to written investment guidelines with key objectives which include the safeguard of principal and adequate liquidity to meet anticipated redemptions. The fair value of the loaned securities is monitored on a daily basis, with additional collateral obtained or refunded as the fair value of the loaned securities changes. The collateral is held by the third-party banking institution, and the collateral can only be accessed in the event that the institution borrowing the securities is in default under the lending agreement. As a result of these restrictions, we consider our securities lending activities to be non-cash investing and financing activities. An indemnification agreement with the lending agent protects us in the event a borrower becomes insolvent or fails to return any of the securities on loan. The fair value of the securities on loan is included in fixed maturities and equity securities. The securities lending collateral is reported as a separate line in total assets with a related liability reflecting our obligation to return the collateral plus interest.
	Similar to securities lending arrangements, securities sold under repurchase agreements, whereby ACE sells securities and repurchases them at a future date for a predetermined price, are accounted for as collateralized investments and borrowings and are recorded at the contractual repurchase amounts plus accrued interest. Assets to be repurchased are the same, or substantially the same, as the assets transferred and the transferor, through right of substitution, maintains the right and ability to redeem the collateral on short notice. The fair value of the underlying securities is included in fixed maturities and equity securities. In contrast to securities lending programs, the use of cash received is not restricted. We report the obligation to return the cash as Short-term debt in the consolidated balance sheets.
	Refer to Note 4 for a discussion on the determination of fair value for ACE's various investment securities.
	f) Cash
	Cash includes cash on hand and deposits with an original maturity of three months or less at time of purchase. Cash held by external money managers is included in Short-term investments.
	We have agreements with a third-party bank provider which implemented two international multi-currency notional cash pooling programs. In each program, participating ACE entities establish deposit accounts in different currencies with the bank provider and each day the credit or debit balances in every account are notionally translated into a single currency (U.S. dollars) and then notionally pooled. The bank extends overdraft credit to any participating ACE entity as needed, provided that the overall notionally-pooled balance of all accounts in each pool at the end of each day is at least zero. Actual cash balances are not physically converted and are not commingled between legal entities. Any overdraft balances incurred under this program by an ACE entity would be guaranteed by ACE Limited (up to $300 million in the aggregate). Our syndicated letter of credit facility allows for same day drawings to fund a net pool overdraft should participating ACE entities overdraw contributed funds from the pool.
	g) Goodwill and other intangible assets
	Goodwill represents the excess of the cost of acquisitions over the fair value of net assets acquired and is not amortized. Goodwill is assigned at acquisition to the applicable reporting unit of the acquired entities giving rise to the goodwill. Goodwill impairment tests are performed annually or more frequently if circumstances indicate a possible impairment.  For goodwill impairment testing, we use a qualitative assessment to determine whether it is more likely than not (i.e., more than a 50 percent probability) that the fair value of a reporting unit is greater than its carrying amount. If our assessment indicates less than a 50 percent probability that fair value exceeds carrying value, we quantitatively estimate a reporting unit's fair value. Goodwill recorded in connection with investments in partially-owned insurance companies is recorded in Investments in partially-owned insurance companies and is also measured for impairment annually.
	Indefinite lived intangible assets are not subject to amortization. Finite lived intangible assets are amortized over their useful lives, generally ranging from 1 to 20 years. The amortization of finite lived intangible assets is reported in Other (income) expense in the consolidated statements of operations. Intangible assets are regularly reviewed for indicators of impairment. Impairment is recognized if the carrying amount is not recoverable from its undiscounted cash flows and is measured as the difference between the carrying amount and fair value.
	h) Unpaid losses and loss expenses
	A liability is established for the estimated unpaid losses and loss expenses under the terms of, and with respect to, ACE's policies and agreements. Similar to premiums that are recognized as revenues over the coverage period of the policy, a liability for unpaid losses and loss expenses is recognized as expense when insured events occur over the coverage period of the policy. This liability includes a provision for both reported claims (case reserves) and incurred but not reported claims (IBNR reserves). IBNR reserve estimates are generally calculated by first projecting the ultimate cost of all losses that have occurred (expected losses), and then subtracting paid losses, case reserves, and loss expenses. The methods of determining such estimates and establishing the resulting liability are reviewed regularly and any adjustments are reflected in operations in the period in which they become known. Future developments may result in losses and loss expenses materially greater or less than recorded amounts.
	Except for net loss and loss expense reserves of $54 million net of discount, held at December 31, 2013, representing certain structured settlements for which the timing and amount of future claim payments are reliably determinable and $52 million, net of discount, of certain reserves for unsettled claims that are discounted in statutory filings, ACE does not discount its P&C loss reserves. This compares with reserves of $58 million for certain structured settlements and $47 million of certain reserves for unsettled claims at December 31, 2012. Structured settlements represent contracts purchased from life insurance companies primarily to settle workers' compensation claims, where payments to the claimant by the life insurance company are expected to be made in the form of an annuity. ACE retains the liability to the claimant in the event that the life insurance company fails to pay. At December 31, 2013, the gross liability due to claimants was $631 million, net of discount, and reinsurance recoverables due from the life insurance companies was $577 million, net of discount. For structured settlement contracts where payments are guaranteed regardless of claimant life expectancy, the amounts recoverable from the life insurance companies at December 31, 2013 are included in Other assets in the consolidated balance sheets, as they do not meet the requirements for reinsurance accounting.
	Included in unpaid losses and loss expenses are liabilities for asbestos and environmental (A&E) claims and expenses. These unpaid losses and loss expenses are principally related to claims arising from remediation costs associated with hazardous waste sites and bodily-injury claims related to asbestos products and environmental hazards. The estimation of these liabilities is particularly sensitive to changes in the legal environment including specific settlements that may be used as precedents to settle future claims. However, ACE does not anticipate future changes in laws and regulations in setting its A&E reserve levels.
Prior period development arises from changes to loss estimates recognized in the current year that relate to loss reserves first reported in previous calendar years and excludes the effect of losses from the development of earned premiums from previous accident years.
For purposes of analysis and disclosure, management views prior period development to be changes in the nominal value of loss estimates from period to period, net of premium and profit commission adjustments on loss sensitive contracts. Prior period development generally excludes changes in loss estimates that do not arise from the emergence of claims, such as those related to uncollectible reinsurance, interest, unallocated loss adjustment expenses, or foreign currency. Accordingly, specific items excluded from prior period development include the following: gains/losses related to foreign currency remeasurement; losses recognized from the early termination or commutation of reinsurance agreements that principally relate to the time value of money; changes in the value of reinsurance business assumed reflected in losses incurred but principally related to the time value of money; and losses that arise from changes in estimates of earned premiums from prior accident years. Except for foreign currency remeasurement, which is included in Net realized gains (losses), these items are included in current year losses.
i) Future policy benefits
The valuation of long-duration contract reserves requires management to make estimates and assumptions regarding expenses, mortality, persistency, and investment yields. Estimates are primarily based on historical experience and information provided by ceding companies and include a margin for adverse deviation. Interest rates used in calculating reserves range from less than 1.0 percent to 6.5 percent and less than 1.0 percent to 4.5 percent at December 31, 2013 and 2012, respectively. Actual results could differ materially from these estimates. Management monitors actual experience and where circumstances warrant, will revise assumptions and the related reserve estimates. Revisions are recorded in the period they are determined.
Certain of our long-duration contracts are supported by assets that do not qualify for separate account reporting under GAAP. These assets are classified as trading securities and reported in Other investments and the offsetting liabilities are reported in Future policy benefits in the consolidated balance sheets. Changes in the fair value of separate account assets that do not qualify for separate account reporting under GAAP are reported in Other income (expense) and the offsetting movements in the liabilities are included in Policy benefits in the consolidated statements of operations.
j) Assumed reinsurance programs involving minimum benefit guarantees under annuity contracts
ACE reinsures various death and living benefit guarantees associated with variable annuities issued primarily in the United States and Japan. Each reinsurance treaty covers variable annuities written during a limited period, typically not exceeding two years. We generally receive a monthly premium during the accumulation phase of the covered annuities (in-force) based on a percentage of either the underlying accumulated account values or the underlying accumulated guaranteed values. Depending on an annuitant's age, the accumulation phase can last many years. To limit our exposure under these programs, all reinsurance treaties include annual or aggregate claim limits and many include an aggregate deductible.
The guarantees which are payable on death, referred to as guaranteed minimum death benefits (GMDB), principally cover shortfalls between accumulated account value at the time of an annuitant's death and either i) an annuitant's total deposits; ii) an annuitant's total deposits plus a minimum annual return; or iii) the highest accumulated account value attained at any policy anniversary date. In addition, a death benefit may be based on a formula specified in the variable annuity contract that uses a percentage of the growth of the underlying contract value. Liabilities for GMDBs are based on cumulative assessments or premiums to date multiplied by a benefit ratio that is determined by estimating the present value of benefit payments and related adjustment expenses divided by the present value of cumulative assessment or expected premiums during the contract period.
Under reinsurance programs covering GLBs, we assume the risk of guaranteed minimum income benefits (GMIB) and guaranteed minimum accumulation benefits (GMAB) associated with variable annuity contracts. The GMIB risk is triggered if, at the time the contract holder elects to convert the accumulated account value to a periodic payment stream (annuitize), the accumulated account value is not sufficient to provide a guaranteed minimum level of monthly income. The GMAB risk is triggered if, at contract maturity, the contract holder's account value is less than a guaranteed minimum value. Our GLB reinsurance product meets the definition of a derivative for accounting purposes and is carried at fair value with changes in fair value recognized in income and classified as described below. As the assuming entity, we are obligated to provide coverage until the earlier of the expiration of the underlying guaranteed benefit or the treaty expiration date. Premiums received under the reinsurance treaties are classified as premium. Expected losses allocated to premiums received are classified as policy benefits and valued similar to GMDB reinsurance. Other changes in fair value, principally arising from changes in expected losses allocated to expected future premiums, are classified as Net realized gains (losses). Fair value represents management's estimate of exit price and thus includes a risk margin. We may recognize a realized loss for other changes in fair value due to adverse changes in the capital markets (i.e., declining interest rates and/or declining equity markets) and changes in policyholder behavior (i.e., increased annuitization or decreased lapse rates) although we expect the business to be profitable. We believe this presentation provides the most meaningful disclosure of changes in the underlying risk within the GLB reinsurance programs for a given reporting period. Refer to Note 5 c) for additional information.
k) Deposit assets and liabilities
Deposit assets arise from ceded reinsurance contracts purchased that do not transfer significant underwriting or timing risk. Under deposit accounting, consideration received or paid, excluding non-refundable fees, is recorded as a deposit asset or liability in the balance sheet as opposed to recording premiums and losses in the statement of operations. Interest income on deposits, representing the consideration received or to be received in excess of cash payments related to the deposit contract, is earned based on an effective yield calculation. The calculation of the effective yield is based on the amount and timing of actual cash flows at the balance sheet date and the estimated amount and timing of future cash flows. The effective yield is recalculated periodically to reflect revised estimates of cash flows. When a change in the actual or estimated cash flows occurs, the resulting change to the carrying amount of the deposit asset is reported as income or expense. Deposit assets of $100 million and $138 million at December 31, 2013 and 2012, respectively, are reflected in Other assets in the consolidated balance sheets and the accretion of deposit assets related to interest pursuant to the effective yield calculation is reflected in Net investment income in the consolidated statements of operations.
Non-refundable fees are earned based on contract terms. Non-refundable fees paid but unearned are reflected in Other assets in the consolidated balance sheets and earned fees are reflected in Other (income) expense in the consolidated statements of operations.
Deposit liabilities include reinsurance deposit liabilities of $131 million and $283 million and contract holder deposit funds of $699 million and $548 million at December 31, 2013 and 2012, respectively. Deposit liabilities are reflected in Accounts payable, accrued expenses, and other liabilities in the consolidated balance sheets. The reinsurance deposit liabilities arise from contracts sold for which there is not a significant transfer of risk. At contract inception, the deposit liability equals net cash received. An accretion rate is established based on actuarial estimates whereby the deposit liability is increased to the estimated amount payable over the contract term. The deposit accretion rate is the rate of return required to fund expected future payment obligations. We periodically reassess the estimated ultimate liability and related expected rate of return. Changes to the deposit liability are generally reflected through Interest expense to reflect the cumulative effect of the period the contract has been in force, and by an adjustment to the future accretion rate of the liability over the remaining estimated contract term.
Contract holder deposit funds represent a liability for investment contracts sold that do not meet the definition of an insurance contract, and certain of these contracts are sold with a guaranteed rate of return. The liability equals accumulated policy account values, which consist of the deposit payments plus credited interest less withdrawals and amounts assessed through the end of the period.
l) Foreign currency remeasurement and translation
The functional currency for each of our foreign operations is generally the currency of the local operating environment. Transactions in currencies other than a foreign operation's functional currency are remeasured into the functional currency and the resulting foreign exchange gains and losses are reflected in Net realized gains (losses) in the consolidated statements of operations. Functional currency assets and liabilities are translated into the reporting currency, U.S. dollars, using period end exchange rates and the related translation adjustments are recorded as a separate component of AOCI. Functional statement of operations amounts expressed in functional currencies are translated using average exchange rates.
m) Administrative expenses
Administrative expenses generally include all operating costs other than policy acquisition costs. The Insurance – North American P&C segment manages and uses an in-house third-party claims administrator, ESIS Inc. (ESIS).  ESIS performs claims management and risk control services for domestic and international organizations that self-insure P&C exposures as well as internal P&C exposures.  The net operating results of ESIS are included within Administrative expenses in the consolidated statements of operations and were $25 million, $23 million, and $21 million for the years ended December 31, 2013, 2012, and 2011, respectively.
n) Income taxes
Income taxes have been recorded related to those operations subject to income taxes. Deferred tax assets and liabilities result from temporary differences between the amounts recorded in the consolidated financial statements and the tax basis of our assets and liabilities. Refer to Note 8 for additional information. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance against deferred tax assets is recorded if it is more likely than not that all, or some portion, of the benefits related to deferred tax assets will not be realized. The valuation allowance assessment considers tax planning strategies, where applicable.
We recognize uncertain tax positions deemed more likely than not of being sustained upon examination.  Recognized income tax positions are measured at the largest amount that is greater than 50 percent likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.
o) Earnings per share
Basic earnings per share is calculated using the weighted-average shares outstanding including participating securities with non-forfeitable rights to dividends such as unvested restricted stock. All potentially dilutive securities including stock options are excluded from the basic earnings per share calculation. In calculating diluted earnings per share, the weighted-average shares outstanding is increased to include all potentially dilutive securities. Basic and diluted earnings per share are calculated by dividing Net income by the applicable weighted-average number of shares outstanding during the year.
p) Cash flow information
Premiums received and losses paid associated with the GLB reinsurance products, which as discussed previously meet the definition of a derivative instrument for accounting purposes, are included within Cash flows from operating activities.  Cash flows, such as settlements and collateral requirements, associated with GLB and all other derivative instruments are included on a net basis within Cash flows from investing activities. Purchases, sales, and maturities of short-term investments are recorded on a net basis within Cash flows from investing activities.
q) Derivatives
ACE recognizes all derivatives at fair value in the consolidated balance sheets and participates in derivative instruments in two principal ways:
(i) To sell protection to customers as an insurance or reinsurance contract that meets the definition of a derivative for accounting purposes. For 2013 and 2012, the reinsurance of GLBs was our primary product falling into this category; and
(ii) To mitigate financial risks, principally arising from investment holdings, products sold, or assets and liabilities held in foreign currencies. For these instruments, changes in assets or liabilities measured at fair value are recorded as realized gains or losses in the consolidated statement of operations.
We did not designate any derivatives as accounting hedges during 2013, 2012, or 2011.
r) Share-based compensation
ACE measures and records compensation cost for all share-based payment awards at grant-date fair value. Compensation costs are recognized for share-based payment awards with only service conditions that have graded vesting schedules on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in substance, multiple awards. Refer to Note 12 for additional information.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Acquisitions	'
	Acquisitions
	PT Asuransi Jaya Proteksi
	We acquired 80 percent of PT Asuransi Jaya Proteksi (JaPro) on September 18, 2012 and our local partner acquired the remaining 20 percent on January 3, 2013. JaPro is one of Indonesia's leading general insurers offering personal lines and commercial coverages. This acquisition diversifies our existing business in Indonesia. The total purchase price for 100 percent of the company was approximately $107 million in cash. JaPro operates in our Insurance – Overseas General segment.
	Fianzas Monterrey
	On April 1, 2013, we acquired Fianzas Monterrey, a leading surety lines company in Mexico offering administrative performance bonds primarily to clients in the construction and industrial sectors, for approximately $293 million in cash. This acquisition expands our global franchise in the surety business and enhances our existing commercial lines and personal accident insurance business in Mexico.
	The acquisition generated $135 million of goodwill, attributable to expected growth and profitability, none of which is expected to be deductible for income tax purposes, and other intangible assets of $73 million, based on ACE's purchase price allocation. The other intangible assets primarily relate to customer lists. Amortization of other intangible assets is included in Other (income) expense in the consolidated statements of operations. Goodwill and other intangible assets arising from this acquisition are included in the Insurance – Overseas General segment.
	ABA Seguros
	On May 2, 2013, we acquired ABA Seguros, a property and casualty insurer in Mexico that provides automobile, homeowners, and small business coverages for approximately $690 million in cash.
	The acquisition generated $283 million of goodwill, attributable to expected growth and profitability, none of which is expected to be deductible for income tax purposes, and other intangible assets of $140 million based on ACE’s purchase price allocation. The other intangible assets primarily relate to distribution channels. Amortization of other intangible assets is included in Other (income) expense in the consolidated statements of operations. Goodwill and other intangible assets arising from this acquisition are included in the Insurance – Overseas General segment.
	To be acquired after 2013
	On January 12, 2014, we announced that we and our local partner have reached a conditional agreement to purchase a 60.9 percent ownership in The Siam Commercial Samaggi Insurance PCL (Samaggi), a general insurance company in Thailand, from Siam Commercial Bank.  This transaction, which is subject to approvals and other customary closing conditions, including Siam Commercial Bank shareholder approval, is expected to be completed in the second quarter of 2014.  On the closing of this transaction, in compliance with Thai regulations, we and our local partner will make a mandatory tender offer for the remaining 39.1 percent ownership of Samaggi on the same terms.  The implied purchase price for 100 percent of the company is approximately $185 million in cash.
	Prior year acquisitions
	We acquired New York Life’s Korea operations on February 1, 2011 and New York Life’s Hong Kong operations on April 1, 2011 for approximately $450 million in cash. These acquired businesses operate in our Life segment, expand our presence in the North Asia market, and complement our life insurance business established in that region. The acquisition generated $91 million of goodwill, none of which is expected to be deductible for income tax purposes, and $163 million of intangible assets. The most significant intangible asset is VOBA.
	We acquired Penn Millers Holding Corporation (PMHC) on November 30, 2011 for approximately $107 million in cash. PMHC’s primary insurance subsidiary, Penn Millers Insurance Company (Penn Millers), is a well-established underwriter in the agribusiness market since 1887. PMHC operates in our Insurance – North American Agriculture segment.
	We acquired Rio Guayas Compania de Seguros y Reaseguros (Rio Guayas), a general insurance company in Ecuador on December 28, 2011 for approximately $65 million in cash. Rio Guayas sells a range of insurance products, including automobile, life, property, and A&H. The acquisition of Rio Guayas helped expand our Latin America capabilities in terms of geography, products, and distribution. Rio Guayas operates in our Insurance – Overseas General segment.
	The consolidated financial statements include results of acquired businesses from the acquisition dates.

Investments

Investments	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Investments	'
	Investments
	a) Fixed maturities
	31-Dec-13	Amortized				Gross			Gross				Fair				OTTI Recognized
		Cost				Unrealized			Unrealized				Value				in AOCI
	(in millions of U.S. dollars)					Appreciation			Depreciation
	Available for sale
	U.S. Treasury and agency	$	2,946			$	62		$	(59	)		$	2,949			$	—
	Foreign	14,336				377			(122		)		14,591				—
	Corporate securities	16,825				777			(132		)		17,470				(6		)
	Mortgage-backed securities	10,937				184			(227		)		10,894				(34		)
	States, municipalities, and political subdivisions	3,362				65			(77		)		3,350				—
		$	48,406			$	1,465		$	(617	)		$	49,254			$	(40	)
	Held to maturity
	U.S. Treasury and agency	$	820			$	16		$	(4	)		$	832			$	—
	Foreign	864				33			—				897				—
	Corporate securities	1,922				83			—				2,005				—
	Mortgage-backed securities	1,341				39			(1		)		1,379				—
	States, municipalities, and political subdivisions	1,151				16			(17		)		1,150				—
		$	6,098			$	187		$	(22	)		$	6,263			$	—
	31-Dec-12	Amortized				Gross			Gross				Fair				OTTI Recognized
		Cost				Unrealized			Unrealized				Value				in AOCI
	(in millions of U.S. dollars)					Appreciation			Depreciation
	Available for sale
	U.S. Treasury and agency	$	3,553			$	183		$	(1	)		$	3,735			$	—
	Foreign	13,016				711			(14		)		13,713				—
	Corporate securities	15,529				1,210			(31		)		16,708				(7		)
	Mortgage-backed securities	10,051				458			(36		)		10,473				(84		)
	States, municipalities, and political subdivisions	2,517				163			(3		)		2,677				—
		$	44,666			$	2,725		$	(85	)		$	47,306			$	(91	)
	Held to maturity
	U.S. Treasury and agency	$	1,044			$	39		$	—			$	1,083			$	—
	Foreign	910				54			—				964				—
	Corporate securities	2,133				142			—				2,275				—
	Mortgage-backed securities	2,028				88			—				2,116				—
	States, municipalities, and political subdivisions	1,155				44			(4		)		1,195				—
		$	7,270			$	367		$	(4	)		$	7,633			$	—
	As discussed in Note 3 c), if a credit loss is indicated on an impaired fixed maturity, an OTTI is considered to have occurred and the portion of the impairment not related to credit losses (non-credit OTTI) is recognized in OCI. Included in the “OTTI Recognized in AOCI” columns above are the cumulative amounts of non-credit OTTI recognized in OCI adjusted for subsequent sales, maturities, and redemptions. OTTI recognized in AOCI does not include the impact of subsequent changes in fair value of the related securities. In periods subsequent to a recognition of OTTI in OCI, changes in the fair value of the related fixed maturities are reflected in Unrealized appreciation (depreciation) in the consolidated statement of shareholders' equity. For the years ended December 31, 2013 and 2012, $25 million and $137 million of net unrealized appreciation, respectively, related to such securities is included in OCI. At December 31, 2013 and 2012, AOCI includes cumulative net unrealized depreciation of $4 million and $25 million, respectively, related to securities remaining in the investment portfolio at those dates for which ACE has recognized a non-credit OTTI.
	Mortgage-backed securities (MBS) issued by U.S. government agencies are combined with all other to be announced mortgage derivatives held (refer to Note 10 a) (iv)) and are included in the category, “Mortgage-backed securities”. Approximately 83 percent and 85 percent, of the total mortgage-backed securities at December 31, 2013 and 2012, respectively, are represented by investments in U.S. government agency bonds. The remainder of the mortgage exposure consists of collateralized mortgage obligations and non-government mortgage-backed securities, the majority of which provide a planned structure for principal and interest payments and carry a rating of AAA by the major credit rating agencies.
	The following table presents fixed maturities by contractual maturity:
		31-Dec							31-Dec
						2013							2012
	(in millions of U.S. dollars)	Amortized Cost				Fair Value			Amortized Cost				Fair Value
	Available for sale
	Due in 1 year or less	$	2,387			$	2,411		$	1,887			$	1,906
	Due after 1 year through 5 years	14,139				14,602			13,411				14,010
	Due after 5 years through 10 years	16,200				16,535			15,032				16,153
	Due after 10 years	4,743				4,812			4,285				4,764
		37,469				38,360			34,615				36,833
	Mortgage-backed securities	10,937				10,894			10,051				10,473
		$	48,406			$	49,254		$	44,666			$	47,306
	Held to maturity
	Due in 1 year or less	$	401			$	405		$	656			$	659
	Due after 1 year through 5 years	2,284				2,363			1,870				1,950
	Due after 5 years through 10 years	1,686				1,723			2,119				2,267
	Due after 10 years	386				393			597				641
		4,757				4,884			5,242				5,517
	Mortgage-backed securities	1,341				1,379			2,028				2,116
		$	6,098			$	6,263		$	7,270			$	7,633
	Expected maturities could differ from contractual maturities because borrowers may have the right to call or prepay obligations, with or without call or prepayment penalties.
	b) Equity securities
		31-Dec				31-Dec
	(in millions of U.S. dollars)	2013				2012
	Cost	$	841			$	707
Gross unrealized appreciation	63				41
Gross unrealized depreciation	(67		)		(4		)
Fair value	$	837			$	744
c) Net realized gains (losses)
In accordance with guidance related to the recognition and presentation of OTTI, when an impairment related to a fixed maturity has occurred, OTTI is required to be recorded in Net income if management has the intent to sell the security or it is more likely than not that we will be required to sell the security before the recovery of its amortized cost. Further, in cases where we do not intend to sell the security and it is more likely than not that we will not be required to sell the security, ACE must evaluate the security to determine the portion of the impairment, if any, related to credit losses. If a credit loss is indicated, an OTTI is considered to have occurred and any portion of the OTTI related to credit losses must be reflected in Net income while the portion of OTTI related to all other factors is recognized in OCI. For fixed maturities held to maturity, OTTI recognized in OCI is accreted from AOCI to the amortized cost of the fixed maturity prospectively over the remaining term of the securities.
Each quarter, securities in an unrealized loss position (impaired securities), including fixed maturities, securities lending collateral, equity securities, and other investments, are reviewed to identify impaired securities to be specifically evaluated for a potential OTTI.
For all non-fixed maturities, OTTI is evaluated based on the following:
•	the amount of time a security has been in a loss position and the magnitude of the loss position;
•	the period in which cost is expected to be recovered, if at all, based on various criteria including economic conditions and other issuer-specific developments; and
•	ACE’s ability and intent to hold the security to the expected recovery period.
As a general rule, we also consider that equity securities in an unrealized loss position for twelve consecutive months are other than temporarily impaired.
Evaluation of potential credit losses related to fixed maturities
We review each fixed maturity in an unrealized loss position to assess whether the security is a candidate for credit loss. Specifically, we consider credit rating, market price, and issuer-specific financial information, among other factors, to assess the likelihood of collection of all principal and interest as contractually due. Securities for which we determine that credit loss is likely are subjected to further analysis to estimate the credit loss recognized in Net income, if any. In general, credit loss recognized in Net income equals the difference between the security’s amortized cost and the net present value of its projected future cash flows discounted at the effective interest rate implicit in the debt security. All significant assumptions used in determining credit losses are subject to change as market conditions evolve.
U.S. Treasury and agency obligations (including agency mortgage-backed securities), foreign government obligations, and states, municipalities, and political subdivisions obligations
U.S. Treasury and agency obligations (including agency mortgage-backed securities), foreign government obligations, and states, municipalities, and political subdivisions obligations represent less than $425 million of gross unrealized loss at December 31, 2013. These securities were evaluated for credit loss primarily using qualitative assessments of the likelihood of credit loss considering credit rating of the issuers and level of credit enhancement, if any. ACE concluded that the high level of creditworthiness of the issuers coupled with credit enhancement, where applicable, supports recognizing no credit loss in net income.
Corporate securities
Projected cash flows for corporate securities (principally senior unsecured bonds) are driven primarily by assumptions regarding probability of default and also the timing and amount of recoveries associated with defaults. ACE developed projected cash flows for corporate securities (principally senior unsecured bonds) using market observable data, issuer-specific information, and credit ratings. We use historical default data by Moody’s Investors Service (Moody’s) rating category to calculate a 1-in-100 year probability of default, which results in a default assumption in excess of the historical mean default rate. Consistent with management's approach, ACE assumed a 32 percent recovery rate (the par value of a defaulted security that will be recovered) across all rating categories rather than using Moody's historical mean recovery rate of 42 percent. We believe that use of a default assumption in excess of the historical mean is conservative in light of current market conditions.
The following table presents default assumptions by Moody's rating category (historical mean default rate provided for comparison):
Moody's Rating Category	1-in-100 Year Default Rate			Historical Mean Default Rate
Investment Grade:
Aaa-Baa	0.0-1.4%			0.0-0.3%
Below Investment Grade:
Ba	4.9	%		1.1	%
B	12.8	%		3.4	%
Caa-C	53.2	%		13.8	%
Application of the methodology and assumptions described above resulted in credit losses recognized in Net income for corporate securities of $11 million, $14 million, and $9 million for the years ended December 31, 2013, 2012, and 2011, respectively.
Mortgage-backed securities
For mortgage-backed securities, credit impairment is assessed using a cash flow model that estimates the cash flows on the underlying mortgages, using the security-specific collateral and transaction structure. The model estimates cash flows from the underlying mortgage loans and distributes those cash flows to various tranches of securities, considering the transaction structure and any subordination and credit enhancements that exist in that structure. The cash flow model incorporates actual cash flows on the mortgage-backed securities through the current period and then projects the remaining cash flows using a number of assumptions, including default rates, prepayment rates, and loss severity rates (the par value of a defaulted security that will not be recovered) on foreclosed properties.
ACE develops specific assumptions using market data, where available, and includes internal estimates as well as estimates published by rating agencies and other third-party sources. ACE projects default rates by mortgage sector considering current underlying mortgage loan performance, generally assuming lower loss severity for Prime sector bonds versus ALT-A and Sub-prime bonds.
These estimates are extrapolated along a default timing curve to estimate the total lifetime pool default rate. Other assumptions used contemplate the actual collateral attributes, including geographic concentrations, rating agency loss projections, rating actions, and current market prices. If cash flow projections indicate that losses will exceed the credit enhancement for a given tranche, then we do not expect to recover our amortized cost basis and we recognize an estimated credit loss in Net income.
Application of the methodology and assumptions described above resulted in credit losses recognized in Net income for mortgage-backed securities of $1 million, $6 million, and $11 million for the years ended December 31, 2013, 2012, and 2011, respectively.
The following table presents the Net realized gains (losses) and the losses included in Net realized gains (losses) and OCI as a result of conditions which caused us to conclude the decline in fair value of certain investments was “other-than-temporary” and the change in net unrealized appreciation (depreciation) of investments:
	Years Ended December 31
(in millions of U.S. dollars)	2013				2012			2011
Fixed maturities:
OTTI on fixed maturities, gross	$	(18	)		$	(26	)	$	(61	)
OTTI on fixed maturities recognized in OCI (pre-tax)	—				1			15
OTTI on fixed maturities, net	(18		)		(25		)	(46		)
Gross realized gains excluding OTTI	237				388			410
Gross realized losses excluding OTTI	(129		)		(133		)	(200		)
Total fixed maturities	90				230			164
Equity securities:
OTTI on equity securities	(2		)		(5		)	(1		)
Gross realized gains excluding OTTI	21				11			15
Gross realized losses excluding OTTI	(4		)		(2		)	(5		)
Total equity securities	15				4			9
OTTI on other investments	(2		)		(7		)	(3		)
Foreign exchange gains (losses)	29				(16		)	(13		)
Investment and embedded derivative instruments	78				(6		)	(143		)
Fair value adjustments on insurance derivative	878				171			(779		)
S&P put options and futures	(579		)		(297		)	(4		)
Other derivative instruments	(2		)		(4		)	(4		)
Other	(3		)		3			(22		)
Net realized gains (losses)	504				78			(795		)
Change in net unrealized appreciation (depreciation) on investments:
Fixed maturities available for sale	(1,798		)		1,099			569
Fixed maturities held to maturity	(82		)		(94		)	(89		)
Equity securities	(41		)		61			(47		)
Other	54				50			40
Income tax (expense) benefit	408				(198		)	(157		)
Change in net unrealized appreciation (depreciation) on investments	(1,459		)		918			316
Total net realized gains (losses) and change in net unrealized appreciation (depreciation) on investments	$	(955	)		$	996		$	(479	)
The following table presents a roll-forward of pre-tax credit losses related to fixed maturities for which a portion of OTTI was recognized in OCI:
	Years Ended December 31
(in millions of U.S. dollars)	2013				2012			2011
Balance of credit losses related to securities still held – beginning of year	$	43			$	74		$	137
Additions where no OTTI was previously recorded	9				8			12
Additions where an OTTI was previously recorded	3				12			8
Reductions for securities sold during the period	(18		)		(51		)	(83		)
Balance of credit losses related to securities still held – end of year	$	37			$	43		$	74
d) Other investments
					31-Dec							31-Dec
					2013							2012
(in millions of U.S. dollars)	Fair Value				Cost			Fair Value				Cost
Investment funds	$	428			$	278		$	395			$	278
Limited partnerships	576				424			531				398
Partially-owned investment companies	1,284				1,284			1,186				1,187
Life insurance policies	180				180			148				148
Policy loans	179				179			164				164
Trading securities	276				273			243				242
Other	53				53			49				48
Total	$	2,976			$	2,671		$	2,716			$	2,465
Investment funds include one highly diversified fund investment as well as several direct funds that employ a variety of investment styles such as long/short equity and arbitrage/distressed. Included in limited partnerships and partially-owned investment companies are 62 individual limited partnerships covering a broad range of investment strategies including large cap buyouts, specialist buyouts, growth capital, distressed, mezzanine, real estate, and co-investments. The underlying portfolio consists of various public and private debt and equity securities of publicly traded and privately held companies and real estate assets.  The underlying investments across various partnerships, geographies, industries, asset types, and investment strategies provide risk diversification within the limited partnership portfolio and the overall investment portfolio.  Trading securities comprise $246 million of mutual funds supported by assets that do not qualify for separate account reporting under GAAP at December 31, 2013 compared with $212 million at December 31, 2012. Trading securities also includes assets held in rabbi trusts of $23 million of equity securities and $7 million of fixed maturities at December 31, 2013, compared with $23 million of equity securities and $8 million of fixed maturities at December 31, 2012.
e) Investments in partially-owned insurance companies
	31-Dec										31-Dec
	2013										2012
(in millions of U.S. dollars, except percentages)	Carrying Value				Issued			Ownership Percentage			Carrying Value				Issued Share Capital				Ownership Percentage			Domicile
					Share
					Capital
Huatai Group	$	365			$	631		20	%		$	350			$	474			20	%		China
Huatai Life Insurance Company	84				379			20	%		84				205				20	%		China
Freisenbruch-Meyer	9				5			40	%		9				5				40	%		Bermuda
ACE Cooperative Insurance Co. – Saudi Arabia	10				27			30	%		9				27				30	%		Saudi Arabia
Russian Reinsurance Company	2				4			23.3	%		2				4				23.3	%		Russia
Total	$	470			$	1,046					$	454			$	715
Huatai Group and Huatai Life Insurance Company provide a range of P&C, life, and investment products.
f) Gross unrealized loss
At December 31, 2013, there were 6,161 fixed maturities out of a total of 25,062 fixed maturities in an unrealized loss position. The largest single unrealized loss in the fixed maturities was $6 million. There were 71 equity securities out of a total of 185 equity securities in an unrealized loss position. The largest single unrealized loss in the equity securities was $58 million. Fixed maturities in an unrealized loss position at December 31, 2013, comprised both investment grade and below investment grade securities for which fair value declined primarily due to widening credit spreads since the date of purchase. Equity securities in an unrealized loss position at December 31, 2013, included foreign fixed income securities held in a commingled fund structure for which fair value declined primarily due to widening credit spreads since the date of purchase.
The following tables present, for all securities in an unrealized loss position (including securities on loan), the aggregate fair value and gross unrealized loss by length of time the security has continuously been in an unrealized loss position:
	0 – 12 Months							Over 12 Months								Total
31-Dec-13	Fair Value				Gross			Fair Value				Gross				Fair Value				Gross
(in millions of U.S. dollars)					Unrealized Loss							Unrealized Loss								Unrealized Loss
U.S. Treasury and agency	$	1,794			$	(57	)	$	31			$	(6	)		$	1,825			$	(63	)
Foreign	4,621				(114		)	201				(8		)		4,822				(122		)
Corporate securities	3,836				(118		)	194				(14		)		4,030				(132		)
Mortgage-backed securities	5,248				(197		)	384				(31		)		5,632				(228		)
States, municipalities, and political subdivisions	2,164				(90		)	84				(4		)		2,248				(94		)
Total fixed maturities	17,663				(576		)	894				(63		)		18,557				(639		)
Equity securities	498				(67		)	—				—				498				(67		)
Other investments	67				(9		)	—				—				67				(9		)
Total	$	18,228			$	(652	)	$	894			$	(63	)		$	19,122			$	(715	)
	0 – 12 Months							Over 12 Months								Total
31-Dec-12	Fair Value				Gross			Fair Value				Gross				Fair Value				Gross
(in millions of U.S. dollars)					Unrealized Loss							Unrealized Loss								Unrealized Loss
U.S. Treasury and agency	$	440			$	(1	)	$	—			$	—			$	440			$	(1	)
Foreign	1,234				(8		)	88				(6		)		1,322				(14		)
Corporate securities	1,026				(23		)	85				(8		)		1,111				(31		)
Mortgage-backed securities	855				(4		)	356				(32		)		1,211				(36		)
States, municipalities, and political subdivisions	316				(3		)	48				(4		)		364				(7		)
Total fixed maturities	3,871				(39		)	577				(50		)		4,448				(89		)
Equity securities	29				(4		)	—				—				29				(4		)
Other investments	68				(5		)	—				—				68				(5		)
Total	$	3,968			$	(48	)	$	577			$	(50	)		$	4,545			$	(98	)
g) Net investment income
	Years Ended December 31
(in millions of U.S. dollars)	2013				2012			2011
Fixed maturities	$	2,093			$	2,134		$	2,196
Short-term investments	29				28			43
Equity securities	37				34			36
Other	105				104			62
Gross investment income	2,264				2,300			2,337
Investment expenses	(120		)		(119		)	(95		)
Net investment income	$	2,144			$	2,181		$	2,242
h) Restricted assets
ACE is required to maintain assets on deposit with various regulatory authorities to support its insurance and reinsurance operations. These requirements are generally promulgated in the statutory regulations of the individual jurisdictions. The assets on deposit are available to settle insurance and reinsurance liabilities. ACE is also required to restrict assets pledged under repurchase agreements. We also use trust funds in certain large reinsurance transactions where the trust funds are set up for the benefit of the ceding companies and generally take the place of letter of credit (LOC) requirements. We also have investments in segregated portfolios primarily to provide collateral or guarantees for LOC and derivative transactions. Included in restricted assets at December 31, 2013 and 2012, are investments, primarily fixed maturities, totaling $16.3 billion and $16.6 billion, respectively, and cash of $162 million and $139 million, respectively.
The following table presents the components of restricted assets:
	31-Dec				31-Dec
(in millions of U.S. dollars)	2013				2012
Trust funds	$	11,315			$	11,389
Deposits with non-U.S. regulatory authorities	1,970				2,133
Assets pledged under repurchase agreements	1,435				1,401
Deposits with U.S. regulatory authorities	1,334				1,338
Other pledged assets	391				456
	$	16,445			$	16,717

Fair_value_measurements

Fair value measurements	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair value measurements	'
	Fair value measurements
	a) Fair value hierarchy
	Fair value of financial assets and financial liabilities is estimated based on the framework established in the fair value accounting guidance. The guidance defines fair value as the price to sell an asset or transfer a liability (an exit price) in an orderly transaction between market participants and establishes a three-level valuation hierarchy based on the reliability of the inputs. The fair value hierarchy gives the highest priority to quoted prices in active markets and the lowest priority to unobservable data.
	The three levels of the hierarchy are as follows:
	•	Level 1 – Unadjusted quoted prices for identical assets or liabilities in active markets;
	•	Level 2 – Includes, among other items, inputs other than quoted prices that are observable for the asset or liability such as interest rates and yield curves, quoted prices for similar assets and liabilities in active markets, and quoted prices for identical or similar assets and liabilities in markets that are not active; and
	•	Level 3 – Inputs that are unobservable and reflect management’s judgments about assumptions that market participants would use in pricing an asset or liability.
	We categorize financial instruments within the valuation hierarchy at the balance sheet date based upon the lowest level of inputs that are significant to the fair value measurement. Accordingly, transfers between levels within the valuation hierarchy occur when there are significant changes to the inputs, such as increases or decreases in market activity, changes to the availability of current prices, changes to the transparency to underlying inputs, and whether there are significant variances in quoted prices. Transfers in and/or out of any level are assumed to occur at the end of the period.
	We use pricing services to obtain fair value measurements for the majority of our investment securities. Based on management’s understanding of the methodologies used, these pricing services only produce an estimate of fair value if there is observable market information that would allow them to make a fair value estimate. Based on our understanding of the market inputs used by the pricing services, all applicable investments have been valued in accordance with GAAP. We do not typically adjust prices obtained from pricing services. The following is a description of the valuation techniques and inputs used to determine fair values for financial instruments carried at fair value, as well as the general classification of such financial instruments pursuant to the valuation hierarchy.
	Fixed maturities
	We use pricing services to estimate fair value measurements for the majority of our fixed maturities. The pricing services use market quotations for fixed maturities that have quoted prices in active markets; such securities are classified within Level 1. For fixed maturities other than U.S. Treasury securities that generally do not trade on a daily basis, the pricing services prepare estimates of fair value measurements using their pricing applications, which include available relevant market information, benchmark curves, benchmarking of like securities, sector groupings, and matrix pricing. Additional valuation factors that can be taken into account are nominal spreads, dollar basis, and liquidity adjustments. The pricing services evaluate each asset class based on relevant market and credit information, perceived market movements, and sector news. The market inputs used in the pricing evaluation, listed in the approximate order of priority include: benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, reference data, and industry and economic events. The extent of the use of each input is dependent on the asset class and the market conditions. Given the asset class, the priority of the use of inputs may change or some market inputs may not be relevant. Additionally, fixed maturities valuation is more subjective when markets are less liquid due to the lack of market based inputs (i.e., stale pricing), which may increase the potential that an investment's estimated fair value is not reflective of the price at which an actual transaction would occur. The overwhelming majority of fixed maturities are classified within Level 2 because the most significant inputs used in the pricing techniques are observable. For a small number of fixed maturities, we obtain a quote from a broker (typically a market maker). Due to the disclaimers on the quotes that indicate that the price is indicative only, we include these fair value estimates in Level 3.
	Equity securities
	Equity securities with active markets are classified within Level 1 as fair values are based on quoted market prices. For equity securities in markets which are less active, fair values are based on market valuations and are classified within Level 2. Equity securities for which pricing is unobservable are classified within Level 3.
	Short-term investments
	Short-term investments, which comprise securities due to mature within one year of the date of purchase that are traded in active markets, are classified within Level 1 as fair values are based on quoted market prices. Securities such as commercial paper and discount notes are classified within Level 2 because these securities are typically not actively traded due to their approaching maturity and, as such, their cost approximates fair value. Short-term investments for which pricing is unobservable are classified within Level 3.
	Other investments
	Fair values for the majority of Other investments including investments in partially-owned investment companies, investment funds, and limited partnerships are based on their respective net asset values or equivalent (NAV). The majority of these investments, for which NAV was used as a practical expedient to measure fair value, are classified within Level 3 because either ACE will never have the contractual option to redeem the investments or will not have the contractual option to redeem the investments in the near term. The remainder of such investments is classified within Level 2. Certain of our long-duration contracts are supported by assets that do not qualify for separate account reporting under GAAP. These assets comprise mutual funds classified within Level 1 in the valuation hierarchy on the same basis as other equity securities traded in active markets. Other investments also includes equity securities and fixed maturities held in rabbi trusts maintained by ACE for deferred compensation plans, which are classified within the valuation hierarchy on the same basis as other equity securities and fixed maturities.
	Securities lending collateral
	The underlying assets included in Securities lending collateral in the consolidated balance sheets are fixed maturities which are classified in the valuation hierarchy on the same basis as other fixed maturities. Excluded from the valuation hierarchy is the corresponding liability related to ACE’s obligation to return the collateral plus interest as it is reported at contract value and not fair value in the consolidated balance sheets.
	Investment derivative instruments
	Actively traded investment derivative instruments, including futures, options, and forward contracts are classified within Level 1 as fair values are based on quoted market prices. The fair value of cross-currency swaps are based on market valuations and are classified within Level 2. Investment derivative instruments are recorded in either Other assets or Accounts payable, accrued expenses, and other liabilities in the consolidated balance sheets.
	Other derivative instruments
	We maintain positions in other derivative instruments including exchange-traded equity futures contracts and option contracts designed to limit exposure to a severe equity market decline, which would cause an increase in expected claims and, therefore, reserves for our guaranteed minimum death benefits (GMDB) and guaranteed living benefits (GLB) reinsurance business. Our position in exchange-traded equity futures contracts is classified within Level 1. The fair value of the majority of the remaining positions in other derivative instruments is based on significant observable inputs including equity security and interest rate indices. Accordingly, these are classified within Level 2. Our position in credit default swaps is typically included within Level 3. Other derivative instruments are recorded in either Other assets or Accounts payable, accrued expenses, and other liabilities in the consolidated balance sheets.
	Separate account assets
	Separate account assets represent segregated funds where investment risks are borne by the customers, except to the extent of certain guarantees made by ACE. Separate account assets comprise mutual funds classified in the valuation hierarchy on the same basis as other equity securities traded in active markets and are classified within Level 1. Separate account assets also include fixed maturities classified within Level 2 because the most significant inputs used in the pricing techniques are observable. Excluded from the valuation hierarchy are the corresponding liabilities as they are reported at contract value and not fair value in the consolidated balance sheets. Separate account assets are recorded in Other assets in the consolidated balance sheets.
	Guaranteed living benefits
	The GLB arises from life reinsurance programs covering living benefit guarantees whereby we assume the risk of guaranteed minimum income benefits (GMIB) and guaranteed minimum accumulation benefits (GMAB) associated with variable annuity contracts. GLB’s are recorded in Accounts payable, accrued expenses, and other liabilities and Future policy benefits in the consolidated balance sheets. For GLB reinsurance, ACE estimates fair value using an internal valuation model which includes current market information and estimates of policyholder behavior. All of the treaties contain claim limits, which are factored into the valuation model. The fair value depends on a number of inputs, including changes in interest rates, changes in equity markets, credit risk, current account value, changes in market volatility, expected annuitization rates, changes in policyholder behavior, and changes in policyholder mortality.
	The most significant policyholder behavior assumptions include lapse rates and the GMIB annuitization rates. Assumptions regarding lapse rates and GMIB annuitization rates differ by treaty, but the underlying methodologies to determine rates applied to each treaty are comparable. The assumptions regarding lapse and GMIB annuitization rates determined for each treaty are based on a dynamic calculation that uses several underlying factors.
	A lapse rate is the percentage of in-force policies surrendered in a given calendar year. All else equal, as lapse rates increase, ultimate claim payments will decrease. In general, the base lapse function assumes low lapse rates (ranging from about 1 percent to 6 percent per annum) during the surrender charge period of the GMIB contract, followed by a “spike” lapse rate (ranging from about 10 percent to 30 percent per annum) in the year immediately following the surrender charge period, and then reverting to an ultimate lapse rate (generally around 10 percent per annum), typically over a 2-year period. This base rate is adjusted downward for policies with more valuable guarantees (policies with guaranteed values far in excess of their account values) by multiplying the base lapse rate by a factor ranging from 8 percent to 68 percent. Additional lapses due to partial withdrawals and older policyholders with tax-qualified contracts (due to required minimum distributions) are also included.
	GMIB annuitization rate is the percentage of policies for which the policyholder will elect to annuitize using the guaranteed benefit provided under the GMIB. All else equal, as GMIB annuitization rates increase, ultimate claim payments will increase, subject to treaty claim limits. All GMIB reinsurance treaties include claim limits to protect ACE in the event that actual annuitization behavior is significantly higher than expected. In general, ACE assumes that GMIB annuitization rates will be higher for policies with more valuable guarantees (policies with guaranteed values far in excess of their account values). In addition, we also assume that GMIB annuitization rates are higher in the first year immediately following the waiting period (the first year the policies are eligible to annuitize using the GMIB) in comparison to all subsequent years. We do not yet have fully credible annuitization experience for all clients.
	•	For clients representing about 37 percent of the total GMIB guaranteed value, we have credible annuitization experience for both the first year and also subsequent years of GMIB eligibility.  The annuitization function reflects the actual experience: the maximum annuitization rates for the first year of GMIB eligibility vary from 7 percent to 12 percent per annum; the maximum annuitization rates for subsequent years of GMIB eligibility vary from 7 percent to 10 percent per annum.
	•	For clients representing about 37 percent of the total GMIB guaranteed value, we have credible annuitization experience only for the first year of GMIB eligibility.  The annuitization function reflects the actual experience for the first year only: the maximum annuitization rates for the first year of GMIB eligibility vary from 14 percent to 55 percent per annum.  The annuitization function for subsequent years of GMIB eligibility is a weighted average (with a heavier weighting on credible experience from other clients) of three different annuitization functions with maximum per annum annuitization rates of 7 percent, 15 percent, and 30 percent.
	•	For clients representing about 26 percent of the total GMIB guaranteed value, we do not have any credible annuitization experience.  The annuitization function for the first year of GMIB eligibility is a weighted average (with a heavier weighting on credible observed experience from other clients) of three different annuitization functions with maximum per annum annuitization rates of 7 percent, 15 percent, and 55 percent.  For subsequent years of GMIB eligibility, these three functions have maximum per annum annuitization rates of 7 percent, 12 percent, and 30 percent.
	The effect of changes in key market factors on assumed lapse and annuitization rates reflect emerging trends using data available from cedants. For treaties with limited experience, rates are established in line with data received from other ceding companies adjusted, as appropriate, with industry estimates. The model and related assumptions are continuously re-evaluated by management and enhanced, as appropriate, based upon additional experience obtained related to policyholder behavior and availability of more information, such as market conditions, market participant assumptions, and demographics of in-force annuities.
	During the fourth quarter of 2013, we completed an in-depth review of actual policyholder lapse and annuitization behavior by treaty for our variable annuity reinsurance business. As a greater percentage of our clients’ policyholders have reached the ultimate lapse rate period and have become eligible to annuitize in the past year, we determined that experience was now credible enough to warrant a more robust evaluation of our assumptions compared to actual experience. As a result of our review, we made several adjustments to our lapse assumptions, the most significant of which was a reduction in lapses for most large, in-the-money, GMIB policies. The change in lapse assumptions increased the fair value of GLB liabilities and generated a realized loss of $104 million. We also made several adjustments to our annuitization assumptions, which generally lowered the utilization rates for most clients, while raising it for one client. The change in annuitization assumptions decreased the fair value of GLB liabilities and generated a realized gain of $64 million. We will continue to monitor actual policyholder behavior against our assumptions and make adjustments as appropriate. Also, during the fourth quarter of 2013, we realized a gain of $92 million related to an out-of-period adjustment for an error in a market valuation model. We evaluated the quantitative and qualitative aspects of this correction and concluded that the impact of recognizing this adjustment is not material to the consolidated financial statements and all prior period consolidated financial statements.
	For the years ended December 31, 2013, 2012, and 2011, we made minor technical refinements to the model with a favorable net income impact of approximately $9 million, $49 million, and $14 million, respectively.
	We view the variable annuity reinsurance business as having a similar risk profile to that of catastrophe reinsurance, with the probability of a cumulative long-term economic net loss relatively small at the time of pricing. However, adverse changes in market factors and policyholder behavior will have an adverse impact on net income, which may be material. Because of the significant use of unobservable inputs including policyholder behavior, GLB reinsurance is classified within Level 3.
	The following tables present, by valuation hierarchy, the financial instruments measured at fair value on a recurring basis:
	31-Dec-13	Level 1				Level 2				Level 3				Total
	(in millions of U.S. dollars)
	Assets:
	Fixed maturities available for sale
	U.S. Treasury and agency	$	1,626			$	1,323			$	—			$	2,949
	Foreign	223				14,324				44				14,591
	Corporate securities	—				17,304				166				17,470
	Mortgage-backed securities	—				10,886				8				10,894
	States, municipalities, and political subdivisions	—				3,350				—				3,350
		1,849				47,187				218				49,254
	Equity securities	373				460				4				837
	Short-term investments	953				803				7				1,763
	Other investments	305				231				2,440				2,976
	Securities lending collateral	—				1,632				—				1,632
	Investment derivative instruments	19				—				—				19
	Other derivative instruments	—				6				—				6
	Separate account assets	1,145				81				—				1,226
	Total assets measured at fair value	$	4,644			$	50,400			$	2,669			$	57,713
	Liabilities:
	Investment derivative instruments	$	6			$	—			$	—			$	6
	Other derivative instruments	60				2				—				62
	GLB(1)	—				—				193				193
	Total liabilities measured at fair value	$	66			$	2			$	193			$	261
	(1)	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. Refer to Note 5 c) for additional information.
	December 31, 2012	Level 1				Level 2				Level 3				Total
(in millions of U.S. dollars)
Assets:
Fixed maturities available for sale
U.S. Treasury and agency	$	2,050			$	1,685			$	—			$	3,735
Foreign	222				13,431				60				13,713
Corporate securities	20				16,586				102				16,708
Mortgage-backed securities	—				10,460				13				10,473
States, municipalities, and political subdivisions	—				2,677				—				2,677
	2,292				44,839				175				47,306
Equity securities	253				488				3				744
Short-term investments	1,503				725				—				2,228
Other investments	268				196				2,252				2,716
Securities lending collateral	—				1,791				—				1,791
Investment derivative instruments	11				—				—				11
Other derivative instruments	(6		)		30				—				24
Separate account assets	872				71				—				943
Total assets measured at fair value	$	5,193			$	48,140			$	2,430			$	55,763
Liabilities:
GLB(1)	$	—			$	—			$	1,119			$	1,119
(1)	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. Refer to Note 5 c) for additional information.
The transfers from Level 1 to Level 2 were $19 million and there were no transfers from Level 2 to Level 1 during the year ended December 31, 2013. The transfers from Level 1 to Level 2 were $40 million and the transfers from Level 2 to Level 1 were $15 million during the year ended December 31, 2012. The transfers between Level 1 and Level 2 during the year ended December 31, 2011 were not material.
Fair value of alternative investments
Included in Other investments in the fair value hierarchy at December 31, 2013 and 2012 are investment funds, limited partnerships, and partially-owned investment companies measured at fair value using NAV as a practical expedient. At December 31, 2013, there were no probable or pending sales related to any of the investments measured at fair value using NAV.
The following table presents, by investment category, the expected liquidation period, fair value, and maximum future funding commitments of alternative investments:
			31-Dec								31-Dec
			2013								2012
(in millions of U.S. dollars)	Expected		Fair Value				Maximum				Fair Value				Maximum
	Liquidation						Future Funding								Future Funding
	Period of Underlying Assets						Commitments								Commitments
Financial	5 to 9 Years		$	256			$	129			$	225			$	111
Real estate	3 to 9 Years		322				92				292				62
Distressed	6 to 9 Years		180				230				192				152
Mezzanine	6 to 9 Years		276				252				284				279
Traditional	3 to 8 Years		813				456				711				587
Vintage	1 to 3 Years		13				—				14				—
Investment funds	Not Applicable		428				—				395				—
			$	2,288			$	1,159			$	2,113			$	1,191
Included in all categories in the above table except for Investment funds are investments for which ACE will never have the contractual option to redeem but receives distributions based on the liquidation of the underlying assets. Further, for all categories except for Investment funds, ACE does not have the ability to sell or transfer the investments without the consent from the general partner of individual funds.
Investment Category		Consists of investments in private equity funds:
Financial		targeting financial services companies such as financial institutions and insurance services worldwide
Real estate		targeting global distress opportunities, value added U.S. properties, and global mezzanine debt securities in the commercial real estate market
Distressed		targeting distressed debt/credit and equity opportunities in the U.S
Mezzanine		targeting private mezzanine debt of large-cap and mid-cap companies in the U.S. and worldwide
Traditional		employing traditional private equity investment strategies such as buyout and venture with different geographical focuses including Brazil, Asia, Europe, and the U.S.
Vintage		made before 2002 and where the funds’ commitment periods had already expired
Investment funds
ACE’s investment funds employ various investment strategies such as long/short equity and arbitrage/distressed. Included in this category are investments for which ACE has the option to redeem at agreed upon value as described in each investment fund’s subscription agreement. Depending on the terms of the various subscription agreements, investment fund investments may be redeemed monthly, quarterly, semi-annually, or annually. If ACE wishes to redeem an investment fund investment, it must first determine if the investment fund is still in a lock-up period (a time when ACE cannot redeem its investment so that the investment fund manager has time to build the portfolio). If the investment fund is no longer in its lock-up period, ACE must then notify the investment fund manager of its intention to redeem by the notification date prescribed by the subscription agreement. Subsequent to notification, the investment fund can redeem ACE’s investment within several months of the notification. Notice periods for redemption of the investment funds range between 5 and 120 days. ACE can redeem its investment funds without consent from the investment fund managers.
Level 3 financial instruments
The fair values of assets and liabilities measured at fair value using significant unobservable inputs (Level 3) consist of various inputs and assumptions that management makes when determining fair value. Management analyzes changes in fair value measurements classified within Level 3 by comparing pricing and returns of our investments to benchmarks, including month-over-month movements, investment credit spreads, interest rate movements, and credit quality of securities.
The following table presents the significant unobservable inputs used in the Level 3 liability valuations. Excluded from the table below are inputs used to determine the fair value of Level 3 assets which are based on single broker quotes or net asset value and contain no quantitative unobservable inputs developed by management.
(in millions of U.S. dollars, except for percentages)	Fair Value at				Valuation		Significant		Ranges
	December 31, 2013				Technique		Unobservable Inputs
GLB(1)	$	193			Actuarial model		Lapse rate		1% – 30%
							Annuitization rate		0% – 55%
(1)	Discussion of the most significant inputs used in the fair value measurement of GLB and the sensitivity of those assumptions is included within Note 4 a) Guaranteed living benefits.
The following tables present a reconciliation of the beginning and ending balances of financial instruments measured at fair value using significant unobservable inputs (Level 3):
	Assets																								Liabilities
	Available-for-Sale Debt Securities													Equity				Short-term investments			Other				GLB(1)
Year Ended December 31, 2013	Foreign				Corporate				MBS					securities							investments
(in millions of U.S. dollars)					securities
Balance, beginning of year	$	60			$	102			$	13				$	3			$	—		$	2,252			$	1,119
Transfers into Level 3	36				47				—					8				8			—				—
Transfers out of Level 3	(54		)		(31		)		—					(1		)		(2		)	—				—
Change in Net Unrealized Gains (Losses) included in OCI	—				—				—					(6		)		—			45				—
Net Realized Gains/Losses	1				(2		)		—					4				—			(2		)		(926		)
Purchases	24				75				—					2				3			551				—
Sales	(21		)		(7		)		(3		)			(6		)		(1		)	(10		)		—
Settlements	(2		)		(18		)		(2		)			—				(1		)	(396		)		—
Balance, end of year	$	44			$	166			$	8				$	4			$	7		$	2,440			$	193
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	—			$	(2	)		$	—				$	—			$	—		$	(2	)		$	(926	)
(1)	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. Refer to Note 5 c) for additional information.
	Assets																														Liabilities
	Available-for-Sale Debt Securities																				Equity			Other				Other			GLB(1)
Year Ended December 31, 2012	U.S.				Foreign				Corporate				MBS				States,				securities			investments				derivative
	Treasury								securities								municipalities,											instruments
	and																and political
(in millions of U.S. dollars)	Agency																subdivisions
Balance, beginning of year	$	5			$	33			$	134			$	28			$	1			$	13		$	1,877			$	3		$	1,319
Transfers into Level 3	—				49				37				22				1				2			53				—			—
Transfers out of Level 3	(4		)		(13		)		(46		)		(35		)		(1		)		(11		)	—				—			—
Change in Net Unrealized Gains (Losses) included in OCI	—				(1		)		6				—				—				—			55				—			—
Net Realized Gains/Losses	—				—				(1		)		—				—				—			(7		)		(4		)	(200		)
Purchases	—				46				24				9				—				4			520				3			—
Sales	—				(53		)		(19		)		(7		)		—				(5		)	(9		)		—			—
Settlements	(1		)		(1		)		(33		)		(4		)		(1		)		—			(237		)		(2		)	—
Balance, end of year	$	—			$	60			$	102			$	13			$	—			$	3		$	2,252			$	—		$	1,119
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	—			$	—			$	—			$	—			$	—			$	—		$	(7	)		$	—		$	(200	)
(1)	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. The liability for GLB reinsurance was $1.4 billion at December 31, 2012 and $1.5 billion at December 31, 2011, which includes a fair value derivative adjustment of $1.1 billion and $1.3 billion, respectively.
					Assets																										Liabilities
					Available-for-Sale Debt Securities																										GLB(1)
Year Ended December 31, 2011	U.S.				Foreign				Corporate				MBS				States,				Equity			Other				Other
	Treasury								securities								municipalities,				securities			investments				derivative
	and																and political											instruments
(in millions of U.S. dollars)	Agency																subdivisions
Balance, beginning of year	$	—			$	26			$	115			$	39			$	2			$	13		$	1,432			$	4		$	507
Transfers into Level 3	—				9				42				4				—				—			—				—			—
Transfers out of Level 3	—				(18		)		(4		)		(48		)		—				—			—				—			—
Change in Net Unrealized Gains (Losses) included in OCI	—				(1		)		(2		)		—				—				(1		)	93				—			—
Net Realized Gains/Losses	—				—				(3		)		—				—				4			(3		)		2			812
Purchased	5				23				32				59				—				5			602				—			—
Sales	—				(3		)		(27		)		(17		)		—				(8		)	(55		)		—			—
Settlements	—				(3		)		(19		)		(9		)		(1		)		—			(192		)		(3		)	—
Balance, end of year	$	5			$	33			$	134			$	28			$	1			$	13		$	1,877			$	3		$	1,319
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	—			$	—			$	—			$	—			$	—			$	—		$	(3	)		$	(1	)	$	812
(1)	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. The liability for GLB reinsurance was $1.5 billion at December 31, 2011 and $648 million at December 31, 2010, which includes a fair value derivative adjustment of $1.3 billion and $507 million, respectively.
b) Financial instruments disclosed, but not measured, at fair value
ACE uses various financial instruments in the normal course of its business. Our insurance contracts are excluded from fair value of financial instruments accounting guidance, and therefore, are not included in the amounts discussed below.
The carrying values of cash, other assets, other liabilities, and other financial instruments not included below approximated their fair values.
Investments in partially-owned insurance companies
Fair values for investments in partially-owned insurance companies are based on ACE’s share of the net assets based on the financial statements provided by those companies.
Short- and long-term debt and trust preferred securities
Where practical, fair values for short-term debt, long-term debt, and trust preferred securities are estimated using discounted cash flow calculations based principally on observable inputs including incremental borrowing rates, which reflect ACE’s credit rating, for similar types of borrowings with maturities consistent with those remaining for the debt being valued.
The following tables present fair value, by valuation hierarchy, and carrying value of the financial instruments not measured at fair value:
31-Dec-13	Fair Value															Carrying Value
(in millions of U.S. dollars)	Level 1				Level 2				Level 3				Total
Assets:
Fixed maturities held to maturity
U.S. Treasury and agency	$	596			$	236			$	—			$	832		$	820
Foreign	—				897				—				897			864
Corporate securities	—				1,990				15				2,005			1,922
Mortgage-backed securities	—				1,379				—				1,379			1,341
States, municipalities, and political subdivisions	—				1,150				—				1,150			1,151
	596				5,652				15				6,263			6,098
Partially-owned insurance companies	—				—				470				470			470
Total assets	$	596			$	5,652			$	485			$	6,733		$	6,568
Liabilities:
Short-term debt	$	—			$	1,913			$	—			$	1,913		$	1,901
Long-term debt	—				4,088				—				4,088			3,807
Trust preferred securities	—				438				—				438			309
Total liabilities	$	—			$	6,439			$	—			$	6,439		$	6,017
31-Dec-12	Fair Value															Carrying Value
(in millions of U.S. dollars)	Level 1				Level 2				Level 3				Total
Assets:
Fixed maturities held to maturity
U.S. Treasury and agency	$	619			$	464			$	—			$	1,083		$	1,044
Foreign	—				964				—				964			910
Corporate securities	—				2,257				18				2,275			2,133
Mortgage-backed securities	—				2,116				—				2,116			2,028
States, municipalities, and political subdivisions	—				1,195				—				1,195			1,155
	619				6,996				18				7,633			7,270
Partially-owned insurance companies	—				—				454				454			454
Total assets	$	619			$	6,996			$	472			$	8,087		$	7,724
Liabilities:
Short-term debt	$	—			$	1,401			$	—			$	1,401		$	1,401
Long-term debt	—				3,916				—				3,916			3,360
Trust preferred securities	—				446				—				446			309
Total liabilities	$	—			$	5,763			$	—			$	5,763		$	5,070

Reinsurance

Reinsurance	12 Months Ended
	Dec. 31, 2013
Reinsurance Disclosures [Abstract]	'
Reinsurance	'
	Reinsurance
	a) Consolidated reinsurance
	ACE purchases reinsurance to manage various exposures including catastrophe risks. Although reinsurance agreements contractually obligate ACE's reinsurers to reimburse it for the agreed-upon portion of its gross paid losses, they do not discharge ACE's primary liability. The amounts for net premiums written and net premiums earned in the consolidated statements of operations are net of reinsurance. The following table presents direct, assumed, and ceded premiums:
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012				2011
	Premiums written
	Direct	$	19,212			$	18,144			$	17,626
	Assumed		3,616				3,449				3,205
	Ceded		(5,803	)			(5,518	)			(5,459	)
	Net	$	17,025			$	16,075			$	15,372
	Premiums earned
	Direct	$	18,856			$	17,802			$	17,534
	Assumed		3,479				3,302				3,349
	Ceded		(5,722	)			(5,427	)			(5,496	)
	Net	$	16,613			$	15,677			$	15,387
	For the years ended December 31, 2013, 2012, and 2011, reinsurance recoveries on losses and loss expenses incurred were $3.1 billion, $4.3 billion, and $3.3 billion, respectively.
	b) Reinsurance recoverable on ceded reinsurance
			31-Dec					31-Dec
	(in millions of U.S. dollars)		2013					2012
	Reinsurance recoverable on unpaid losses and loss expenses (1)			$	10,612				$	11,399
	Reinsurance recoverable on paid losses and loss expenses (1)			615					679
	Net reinsurance recoverable on losses and loss expenses			$	11,227				$	12,078
	(1)	Net of a provision for uncollectible reinsurance.
	We evaluate the financial condition of our reinsurers and potential reinsurers on a regular basis and also monitor concentrations of credit risk with reinsurers. The provision for uncollectible reinsurance is required principally due to the potential failure of reinsurers to indemnify ACE, primarily because of disputes under reinsurance contracts and insolvencies. We have established provisions for amounts estimated to be uncollectible. At December 31, 2013 and 2012, we recorded a provision for uncollectible reinsurance of $390 million and $439 million, respectively.
	The following tables present a listing, at December 31, 2013, of the categories of ACE's reinsurers. The first category, largest reinsurers, represents all groups of reinsurers where the gross recoverable exceeds one percent of ACE's total shareholders' equity. The provision for uncollectible reinsurance for the largest reinsurers, other reinsurers rated A- or better, and other reinsurers with ratings lower than A- is principally based on an analysis of the credit quality of the reinsurer and collateral balances. Other pools and government agencies include amounts backed by certain state and federal agencies. In certain states, insurance companies are required by law to participate in these pools. Structured settlements include annuities purchased from life insurance companies to settle claims. Since we retain the ultimate liability in the event that the life company fails to pay, we reflect the amount as a liability and a recoverable/receivable for GAAP purposes. Captives include companies established and owned by our insurance clients to assume a significant portion of their direct insurance risk from ACE (they are structured to allow clients to self-insure a portion of their insurance risk). It is generally our policy to obtain collateral equal to expected losses. Where appropriate, exceptions are granted but only with review and approval at a senior officer level. The final category, Other, includes amounts recoverable that are in dispute or are from companies that are in supervision, rehabilitation, or liquidation. We establish the provision for uncollectible reinsurance in this category based on a case-by-case analysis of individual situations including the merits of the underlying matter, credit and collateral analysis, and consideration of our collection experience in similar situations.
	(in millions of U.S. dollars, except percentages)	2013					Provision					% of Gross
	Categories
	Largest reinsurers		$	5,117				$	78			1.5	%
	Other reinsurers balances rated A- or better		2,901					36				1.2	%
	Other reinsurers balances with ratings lower than A- or not rated		587					103				17.5	%
	Other pools and government agencies		338					21				6.2	%
	Structured settlements		577					12				2.1	%
	Captives		1,762					14				0.8	%
	Other		335					126				37.6	%
	Total		$	11,617				$	390			3.4	%
	Largest Reinsurers
	Alleghany Corp (Transatlantic)	Lloyd's of London		Swiss Re Group
	Berkshire Hathaway Insurance Group	Munich Re Group		XL Capital Group
	HDI Group (Hanover Re)	Partner Re Group
	c) Assumed life reinsurance programs involving minimum benefit guarantees under annuity contracts
	The following table presents income and expenses relating to GMDB and GLB reinsurance. GLBs include GMIBs as well as some GMABs originating in Japan.
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012				2011
	GMDB
	Net premiums earned	$	77			$	85			$	98
	Policy benefits and other reserve adjustments	$	73			$	60			$	59
	GLB
	Net premiums earned	$	149			$	160			$	163
	Policy benefits and other reserve adjustments	27				61				47
	Net realized gains (losses)	929				203				(812		)
	Gain (loss) recognized in income	$	1,051			$	302			$	(696	)
	Net cash received	$	126			$	149			$	161
	Net (increase) decrease in liability	$	925			$	153			$	(857	)
	At December 31, 2013, reported liabilities for GMDB and GLB reinsurance were $100 million and $427 million, respectively, compared with $90 million and $1.4 billion, respectively, at December 31, 2012. The reported liability for GLB reinsurance of $427 million at December 31, 2013, and $1.4 billion at December 31, 2012, includes a fair value derivative adjustment of$193 million and $1.1 billion, respectively. Included in Net realized gains (losses) in the table above are gains (losses) related to foreign exchange and other fair value derivative adjustments. Reported liabilities for both GMDB and GLB reinsurance are determined using internal valuation models. Such valuations require considerable judgment and are subject to significant uncertainty. The valuation of these products is subject to fluctuations arising from, among other factors, changes in interest rates, changes in equity markets, changes in credit markets, changes in the allocation of the investments underlying annuitants’ account values, and assumptions regarding future policyholder behavior. These models and the related assumptions are continually reviewed by management and enhanced, as appropriate, based upon improvements in modeling assumptions and availability of more information, such as market conditions and demographics of in-force annuities.
	Variable Annuity Net Amount at Risk
	(i) Reinsurance covering the GMDB risk only
	At December 31, 2013 and 2012, the net amount at risk from reinsurance programs covering the GMDB risk only was $586 million and $1.3 billion, respectively.
	For reinsurance programs covering the GMDB risk only, the net amount at risk is defined as the present value of future claim payments under the following assumptions:
	•	policy account values and guaranteed values are fixed at the valuation date (December 31, 2013 and 2012, respectively);
	•	there are no lapses or withdrawals;
	•	mortality according to 100 percent of the Annuity 2000 mortality table;
	•	future claims are discounted in line with the discounting assumption used in the calculation of the benefit reserve averaging between 2.0 percent and 3.0 percent; and
	•	reinsurance coverage ends at the earlier of the maturity of the underlying variable annuity policy or the reinsurance treaty.
The total claim amount payable on reinsurance programs covering the GMDB risk only, if all the cedants’ policyholders were to die immediately at December 31, 2013 was approximately $668 million. This takes into account all applicable reinsurance treaty claim limits.
(ii) Reinsurance covering the GLB risk only
At December 31, 2013 and 2012, the net amount at risk from reinsurance programs covering the GLB risk only was $136 million and $445 million, respectively.
For reinsurance programs covering the GLB risk only, the net amount at risk is defined as the present value of future claim payments under the following assumptions:
•	policy account values and guaranteed values are fixed at the valuation date (December 31, 2013 and 2012, respectively);
•	there are no deaths, lapses, or withdrawals;
•	policyholders annuitize at a frequency most disadvantageous to ACE (in other words, annuitization at a level that maximizes claims taking into account the treaty limits) under the terms of the reinsurance contracts;
•	for annuitizing policyholders, the GMIB claim is calculated using interest rates in line with those used in calculating the reserve;
•	future claims are discounted in line with the discounting assumption used in the calculation of the benefit reserve averaging between 3.5 percent and 4.5 percent; and
•	reinsurance coverage ends at the earlier of the maturity of the underlying variable annuity policy or the reinsurance treaty.
(iii) Reinsurance covering both the GMDB and GLB risks on the same underlying policyholders
At December 31, 2013 and 2012, the GMDB net amount at risk from reinsurance programs covering both the GMDB and GLB risks on the same underlying policyholders was $73 million and $116 million, respectively.
At December 31, 2013 and 2012, the GLB net amount at risk from reinsurance programs covering both the GMDB and GLB risks on the same underlying policyholders was $141 million and $655 million, respectively.
These net amounts at risk reflect the interaction between the two types of benefits on any single policyholder (eliminating double-counting), and therefore the net amounts at risk should be considered additive.
For reinsurance programs covering both the GMDB and GLB risks on the same underlying policyholders, the net amount at risk is defined as the present value of future claim payments under the following assumptions:
•	policy account values and guaranteed values are fixed at the valuation date (December 31, 2013 and 2012, respectively);
•	there are no lapses, or withdrawals;
•	mortality according to 100 percent of the Annuity 2000 mortality table;
•	policyholders annuitize at a frequency most disadvantageous to ACE (in other words, annuitization at a level that maximizes claims taking into account the treaty limits) under the terms of the reinsurance contracts;
•	for annuitizing policyholders, the GMIB claim is calculated using interest rates in line with those used in calculating the reserve;
•	future claims are discounted in line with the discounting assumption used in the calculation of the benefit reserve averaging between 3.0 percent and 4.0 percent; and
•	reinsurance coverage ends at the earlier of the maturity of the underlying variable annuity policy or the reinsurance treaty.
The total claim amount payable on reinsurance programs covering both the GMDB and GLB risks on the same underlying policyholders, if all of the cedants’ policyholders were to die immediately at December 31, 2013 was approximately $84 million. This takes into account all applicable reinsurance treaty claim limits. Although there would be an increase in death claims resulting from 100 percent immediate mortality of all policyholders, the GLB claims would be zero.
The average attained age of all policyholders under sections i), ii), and iii) above, weighted by the guaranteed value of each reinsured policy, is approximately 68 years.

Intangible_Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Intangible assets	'
	Intangible assets
	Included in Goodwill and other intangible assets in the consolidated balance sheets at December 31, 2013 and 2012, are goodwill of $4.6 billion and $4.3 billion, respectively, and other intangible assets of $801 million and $656 million, respectively.
	The following table presents a roll-forward of Goodwill by segment:
	(in millions of U.S. dollars)	Insurance – North American			Insurance – North American Agriculture			Insurance – Overseas General			Global Reinsurance		Life			ACE Consolidated
		P&C
	Balance at December 31, 2011	$	1,216		$	134		$	1,603		$	365	$	830		$	4,148
	Purchase price allocation adjustment	—			—			—			—		4			4
	Acquisition of JaPro	—			—			123			—		—			123
	Foreign exchange revaluation and other	3			—			38			—		3			44
	Balance at December 31, 2012	$	1,219		$	134		$	1,764		$	365	$	837		$	4,319
	Acquisition of Fianzas Monterrey	—			—			135			—		—			135
	Acquisition of ABA Seguros	—			—			283			—		—			283
	Foreign exchange revaluation and other	(4		)	—			(128		)	—		(2		)	(134		)
	Balance at December 31, 2013	$	1,215		$	134		$	2,054		$	365	$	835		$	4,603
	Included in other intangible assets at December 31, 2013 and 2012, are intangible assets subject to amortization of $695 million and $554 million, respectively, and intangible assets not subject to amortization of $106 million and $102 million, respectively. Intangible assets subject to amortization include agency relationships, software, client lists, renewal rights, and trademarks, primarily attributable to the acquisitions of Rain and Hail, Fianzas Monterrey, and ABA Seguros. The majority of the balance of intangible assets not subject to amortization relates to Lloyd's of London (Lloyd's) Syndicate 2488 (Syndicate 2488) capacity. Amortization expense related to other intangible assets amounted to $95 million, $51 million, and $29 million for the years ended December 31, 2013, 2012, and 2011, respectively.
	The following table presents a roll-forward of VOBA:
	(in millions of U.S. dollars)	2013			2012			2011
	Balance, beginning of year	$	614		$	676		$	634
	Acquisition of New York Life's Korea operations and Hong Kong operations	—			—			151
	Amortization expense	(64		)	(82		)	(108		)
	Foreign exchange revaluation	(14		)	20			(1		)
	Balance, end of year	$	536		$	614		$	676
	The following table presents estimated amortization expense related to other intangible assets and VOBA for the next five years:
	For the Year Ending December 31	Other intangible assets			VOBA
	(in millions of U.S. dollars)
	2014	$	81		$	55
	2015	62			50
	2016	55			45
	2017	52			40
	2018	49			35
	Total	$	299		$	225

Unpaid_losses_and_loss_expense

Unpaid losses and loss expenses	12 Months Ended
	Dec. 31, 2013
Unpaid Losses And Loss Expenses [Abstract]	'
Unpaid Losses and Loss Expenses	'
	Unpaid losses and loss expenses
	ACE establishes reserves for the estimated unpaid ultimate liability for losses and loss expenses under the terms of its policies and agreements. Reserves include estimates for both claims that have been reported and for IBNR, and include estimates of expenses associated with processing and settling these claims. Reserves are recorded in Unpaid losses and loss expenses in the consolidated balance sheets. The process of establishing loss and loss expense reserves for P&C claims can be complex and is subject to considerable uncertainty as it requires the use of informed estimates and judgments. Our estimates and judgments may be revised as additional experience and other data become available and are reviewed, as new or improved methodologies are developed, or as laws change. We continually evaluate our estimate of reserves in light of developing information and in light of discussions and negotiations with our insureds. While we believe that our reserves for unpaid losses and loss expenses at December 31, 2013 are adequate, new information or trends may lead to future developments in ultimate losses and loss expenses significantly greater or less than the reserves provided. Any such revisions could result in future changes in estimates of losses or reinsurance recoverable and would be reflected in our results of operations in the period in which the estimates are changed.
	The following table presents a reconciliation of unpaid losses and loss expenses:
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012					2011
	Gross unpaid losses and loss expenses, beginning of year		$	37,946			$	37,477				$	37,391
	Reinsurance recoverable on unpaid losses(1)		(11,399		)		(11,602		)			(12,149		)
	Net unpaid losses and loss expenses, beginning of year		26,547				25,875					25,242
	Acquisition of subsidiaries		86				14					92
	Total		26,633				25,889					25,334
	Net losses and loss expenses incurred in respect of losses occurring in:
	Current year		9,878				10,132					10,076
	Prior years		(530		)		(479		)			(556		)
	Total		9,348				9,653					9,520
	Net losses and loss expenses paid in respect of losses occurring in:
	Current year		3,942				4,325					4,209
	Prior years		5,035				4,894					4,657
	Total		8,977				9,219					8,866
	Foreign currency revaluation and other		(173		)		224					(113		)
	Net unpaid losses and loss expenses, end of year		26,831				26,547					25,875
	Reinsurance recoverable on unpaid losses(1)		10,612				11,399					11,602
	Gross unpaid losses and loss expenses, end of year		$	37,443			$	37,946				$	37,477
	(1) Net of provision for uncollectible reinsurance.
	Net losses and loss expenses incurred includes $530 million, $479 million, and $556 million, of net favorable prior period development in the years ended December 31, 2013, 2012, and 2011, respectively. Long-tail lines include lines such as workers’ compensation, general liability, and professional liability; while short-tail lines include lines such as most property lines, energy, personal accident, aviation, marine (including associated liability-related exposures) and agriculture. Significant prior period movements by segment, principally driven by reserve reviews completed during each respective period, are discussed in more detail below. The remaining net development for long-tail and short-tail business for each segment comprises numerous favorable and adverse movements across a number of lines and accident years, none of which is significant individually or in the aggregate.
	Insurance – North American P&C
	Insurance – North American P&C's active operations experienced net favorable prior period development of $327 million in 2013 which was the net result of several underlying favorable and adverse movements driven by the following principal changes:
	•	Net favorable development of $221 million in long-tail business, including:
	•	Favorable development of $72 million in our retail D&O portfolios, primarily impacting the 2008 and prior accident years. Favorable settlements on several large claims drove the favorable development in 2004 and prior accident years, while favorable action in 2008 is primarily due to an increase in weighting applied to experience-based and simulation methods;
	•	Favorable development of $63 million in our medical risk operations, primarily impacting the 2007 to 2009 accident years. Paid and reported loss activity for this business in these accident years continued to be lower than expected and we have increased our weighting applied to experience-based methods; and
	•	Favorable development of $50 million in our U.S. excess casualty and umbrella businesses primarily affecting the 2007 and prior accident years. Reported activity on loss and allocated loss adjustment expenses was lower than expected based on estimates from our prior review. In addition, increased weighting was applied to experience-based methods in the current review for these accident periods;
	•	Net favorable development of $28 million in our national accounts portfolios which consist of commercial auto, general liability and workers' compensation lines of business. This favorable movement was the net impact of favorable and adverse movements, including:
	•	Favorable development of $40 million related to our annual assessment of multi-claimant events including industrial accidents, impacting the 2012 accident year. Consistent with prior years, we reviewed these potential exposures after the close of the accident year to allow for late reporting or identification of significant losses;
	•	Adverse development of $40 million predominantly in workers' compensation, primarily impacting the 2006 and prior accident years. The development was a function of higher than expected reported loss activity, higher allocated loss adjustment expenses, as well as an increase in weighting applied to experience-based methods; and
	•	Net favorable development of $28 million across a number of lines and accident years, none of which was significant individually or in the aggregate.
	•	Favorable development of $25 million in our foreign casualty Controlled Master Program and Cash Flow portfolios affecting the 2009 and prior accident years. Paid and reported loss activity for this business in these accident years continued to be lower than expected and we have increased our weighting applied to experience-based methods;
	•	Favorable development of $106 million in short-tail business, primarily from:
	•	Net favorable development of $45 million in our wholesale property and inland marine portfolios, primarily in accident years 2010 to 2012, due to favorable case incurred emergence and favorable settlements of several large claims; and
	•	Favorable development of $29 million in our political risk business in the 2009 and 2010 accident years primarily due to favorable settlements of a few large claims;
	Insurance – North American P&C's run-off operations incurred adverse prior period development of $193 million in our Westchester and Brandywine run-off operations during 2013, which was the net result of adverse and favorable movements impacting accident years 1996 and prior, driven by the following principal changes:
	•	Adverse development of $161 million related to the completion of the reserve reviews during 2013. The development primarily arose from case specific asbestos and environmental claims related to increased loss and defense cost payment activity and the costs associated with certain case settlements in 2013. Further, we experienced higher than expected paid loss and case reserve activity in our assumed reinsurance portfolio; and
	•	Adverse development of $27 million on unallocated loss adjustment expenses due to run-off operating expenses paid and incurred during 2013.
	Insurance – North American P&C's active operations experienced net favorable prior period development of $348 million in 2012 which was the net result of several underlying favorable and adverse movements driven by the following principal changes:
	•	Net favorable development of $245 million in long-tail business, including:
	•	Favorable development of $73 million in a collection of portfolios of umbrella and excess casualty business, primarily affecting the 2007 and prior accident years. The favorable development was the function of both the continuation of the lower than expected reported loss activity in the period since our last review and an increase in weighting applied to experience-based methods, particularly for the 2006 accident year, as these accident periods matured;
	•	Favorable development of $67 million in our D&O portfolios primarily affecting the 2007 and prior accident years. Case loss activity was lower than expected during the 2012 calendar year, including reductions in our internal estimates of exposure on several potentially large claims. These reductions were a function of changes in account specific circumstances since our prior review;
	•	Favorable development of $57 million in our medical risk operations, primarily in the 2007 and prior accident years. Reported and paid loss activity for these accident years were lower than expected since our prior review; and
	•	Net favorable development of $39 million in our national accounts portfolios which consists of commercial auto liability, general liability, and workers' compensation lines of business. This favorable development was the net impact of favorable and adverse movements, including:
	•	Favorable development of $41 million in the 2011 accident year related to our annual assessment of multi-claimant events including industrial accidents. Consistent with prior years, we reviewed these potential exposures after the close of the accident year to allow for late reporting or identification of significant losses;
	•	Favorable development of $34 million in the 2007 accident year, primarily in workers' compensation. The favorable development was the combined effect of lower than expected incurred loss activity and an increase in weighting applied to experience-based methods; and
	•	Adverse development of $36 million affecting the 2006 and prior accident years largely in workers' compensation. The causes for this adverse movement were various and included adverse development on several specific large claims, higher than expected loss activity in certain accident years, an increase in weighting applied to experience-based methods, and a refinement of our treatment of ceded reinsurance recoveries on a few select treaties due to information which became known since our prior review.
	•	Favorable development of $103 million in short-tail business, primarily from:
	•	Favorable development of $88 million in our property, inland marine and commercial marine businesses primarily arising in the 2009 through 2011 accident years. Reported loss activity during the 2012 calendar was lower than expected, particularly in our high excess property portfolio; and
	•	Favorable development of $27 million in our aviation product lines, primarily general aviation hull and liability, affecting the 2009 and prior accident years. Actual paid and incurred loss activity were lower than expected based on long-term historical averages leading to a reduction in our estimate of ultimate losses.
	Insurance – North American P&C's run-off operations incurred net adverse prior period development of $168 million in our Westchester and Brandywine run-off operations during 2012, which was the net result of adverse and favorable movements impacting accident years 1996 and prior, driven by the following principal changes:
	•	Adverse development of $150 million related to the completion of the reserve review during 2012. The development primarily arose from case specific asbestos and environmental claims related to increased loss and defense cost payment activity and the costs associated with certain case settlements made in 2012. Further, we experienced higher than expected paid loss and case reserve activity in our assumed reinsurance portfolio; and
	•	Adverse development of $18 million on unallocated loss adjustment expenses due to run-off operating expenses paid during 2012.
	Insurance – North American P&C active operations experienced net favorable prior period development of $289 million in 2011, representing 1.8 percent of its beginning of period net unpaid loss and loss expense reserves. Insurance – North American P&C run-off operations incurred net adverse prior period development of $102 million in 2011, representing 0.6 percent of its beginning of period net unpaid loss and loss expense reserves.
	Insurance – North American Agriculture
	Insurance – North American Agriculture experienced net favorable prior period development of $13 million, $12 million, and $8 million in 2013, 2012, and 2011, respectively, in short-tail business across a number of accident years, none of which was significant individually or in the aggregate.
	Insurance – Overseas General
	Insurance – Overseas General experienced net favorable prior period development of $299 million in 2013, which was the net result of several underlying favorable and adverse movements, driven by the following principal changes:
	•	Net favorable development of $127 million in long-tail business, including:
	•	Favorable development of $92 million in casualty (primary and excess). Reserve reviews indicated favorable claim activity of $135 million in accident years 2009 and prior. These reviews reflected an increase in weighting applied to experience-based methods as these accident years continued to mature. Adverse development of $43 million in accident years 2010 to 2012 was primarily due to development in specific individual large claims and also in several accounts now exposed on an excess basis following adverse loss development of the underlying aggregate retention layer; and
•	Net favorable development of $35 million in financial lines. Reserve reviews indicated favorable claim activity of $63 million in accident years 2009 and prior. These reviews reflected an increase in weighting applied to experience-based methods as these accident years continued to mature. Adverse development of $28 million in accident year 2012 was incurred due to notifications on specific large claims.
•	Favorable development of $172 million in short-tail business, primarily from:
•	Favorable development of $104 million across property, technical lines and marine. Favorable development of $69 million in accident years 2010 to 2012 reflected lower than expected loss emergence. In addition, favorable development of $35 million in the property and marine liability lines in accident years 2009 and prior was primarily due to case specific developments;
•	Favorable development of $39 million across accident and health and personal lines primarily reflected lower than expected loss emergence, primarily in accident years 2010 to 2012; and
•	Favorable development of $29 million predominantly in the wholesale aviation business, primarily in accident years 2009 and prior, due to case specific developments.
Insurance – Overseas General experienced net favorable prior period development of $226 million in 2012, which was the net result of several underlying favorable and adverse movements, driven by the following principal changes:
•	Net favorable development of $121 million in long-tail business, including:
•	Favorable development of $150 million in casualty (primary and excess) and financial lines for accident years 2008 and prior. We recognized the impact of favorable loss emergence since the prior study and increased the weighting applied to experience-based methods; and
•	Adverse development of $29 million in casualty (mainly primary) and financial lines for accident years 2009 to 2011 in response to claims emergence primarily in 2011. The adverse development was driven by changes in case specific circumstances on several specific larger claims and, to a lesser extent, increased frequency trends in primary European casualty impacting accident year 2011.
•	Favorable development of $105 million in short-tail business, including property, marine, A&H, and personal lines across multiple geographical regions, and in both retail and wholesale operations, principally as a result of lower than expected loss emergence, mostly in accident years 2009 and 2010.
Insurance – Overseas General experienced net favorable prior period development of $290 million in 2011, representing 4.2 percent of the segment's beginning of period net unpaid loss and loss expense reserves.
Global Reinsurance
Global Reinsurance experienced net favorable prior period development of $84 million in 2013, which was the net result of several underlying favorable and adverse movements, driven by the following principal changes:
•	Net favorable development of $53 million in long-tail business, primarily including:
•	Favorable development of $25 million in professional liability lines, primarily in treaty years 2008 and prior, reflected favorable paid and incurred loss trends and an increase in weighting applied to experience-based methods; and
•	Favorable development of $20 million in medical malpractice business, principally in treaty years 2009 and prior, reflected favorable paid and incurred loss trends and an increase in weighting applied to experience-based methods.
•	Net favorable development of $31 million in short-tail business, primarily in treaty years 2007 to 2012 across property lines (including property catastrophe), trade credit, marine, and surety principally as a result of lower than expected loss emergence.
Global Reinsurance experienced net favorable prior period development of $61 million in 2012, which was the net result of several underlying favorable and adverse movements, driven by the following principal changes:
•	Favorable prior period development of $54 million in long-tail business primarily in treaty years 2008 and prior in casualty and medical malpractice lines. The lower loss estimates arose from a combination of favorable paid and incurred loss trends and increased weighting applied to experience-based methods; and
•	Net favorable development of $29 million in short-tail business, primarily in treaty years 2010 and prior across property lines (including property catastrophe), trade credit, marine, and surety principally as a result of lower than expected loss emergence.
Global Reinsurance experienced net favorable prior period development of $71 million in 2011, representing 3.1 percent of the segment's beginning of period net unpaid loss and loss expense reserves.
Asbestos and environmental (A&E) and other run-off liabilities
a) A&E liabilities
Included in liabilities for losses and loss expenses are amounts for A&E (A&E liabilities). The A&E liabilities principally relate to claims arising from bodily-injury claims related to asbestos products and remediation costs associated with hazardous waste sites. The estimation of A&E liabilities is particularly sensitive to future changes in the legal, social, and economic environments and legislative reforms. ACE has not assumed any such future changes in setting the value of its A&E reserves, which include provisions for both reported and IBNR claims. ACE's A&E reserves are not discounted for GAAP reporting.
The following table presents a roll-forward of consolidated A&E loss reserves (excluding other run-off liabilities), allocated loss expense reserves for A&E exposures, and the provision for uncollectible paid and unpaid reinsurance recoverables:
	Asbestos									Environmental								Total
(in millions of U.S. dollars)	Gross				Net					Gross				Net				Gross					Net
Balance at December 31, 2012 (1)		$	1,886			$	970				$	194			$	136			$	2,080				$	1,106
Incurred activity		125				96					119				75				244					171			(2)
Paid activity		(367		)		(140		)			(118		)		(86		)		(485		)			(226		)
Balance at December 31, 2013		$	1,644			$	926				$	195			$	125			$	1,839				$	1,051
-1	Balances at December 31, 2012 have been adjusted to present claims in a manner consistent with balances disclosed at December 31, 2013.
(2)	Excludes unallocated loss expenses.
The A&E net loss reserves including allocated loss expense reserves and provision for uncollectible reinsurance at December 31, 2013, of $1.1 billion shown in the table above comprise $816 million in reserves in respect of Brandywine operations (see Brandywine run-off section below), $146 million of reserves held by Westchester Specialty (see Westchester Specialty section below), $79 million of reserves held by Insurance – Overseas General, $7 million of reserves held by ACE Bermuda, and $3 million of reserves held by Penn Millers. The incurred activity of $171 million is primarily the result of adverse activity in Brandywine and Westchester of $158 million and $14 million, respectively.
b) A&E and other run-off liabilities
The net figures in the above table (under A&E liabilities section) reflect third-party reinsurance other than reinsurance provided by National Indemnity Company (NICO) under two aggregate excess of loss contracts described below (collectively, the NICO contracts).  ACE excludes the NICO contracts as they cover non-A&E liabilities as well as A&E liabilities.  The split of coverage provided under the NICO contracts for A&E liabilities as compared to non-A&E liabilities is entirely dependent on the timing of the payment of the related claims. ACE's ability to make an estimate of this split is not practicable. ACE believes, instead, that the A&E discussion is best provided excluding the NICO contracts, while separately discussing the NICO contracts in relation to the total subject business, both A&E and other liabilities, covered by those contracts.  With certain exceptions, the NICO contracts provide coverage for the net incurred losses and allocated loss expenses within the limits of coverage and above ACE's retention levels.  These exceptions include losses arising from certain operations of Insurance – Overseas General and participation by ACE Bermuda as a co-reinsurer or retrocessionaire in the NICO contracts.
ACE's exposure to A&E claims principally arises out of liabilities acquired when it purchased Westchester Specialty in 1998 and CIGNA's P&C business in 1999, with the larger exposure contained within the liabilities acquired in the CIGNA transaction. In 1996, prior to ACE's acquisition of CIGNA's P&C business, the Pennsylvania Insurance Commissioner approved a plan to restructure INA Financial Corporation and its subsidiaries (the Restructuring) which included the division of Insurance Company of North America (INA) into two separate corporations that ACE acquired as part of the CIGNA P&C business:
(1) An active insurance company that retained the INA name and continued to write P&C business; and
(2) An inactive run-off company, now called Century Indemnity Company (Century).
As a result of the division, predominantly all A&E and certain other liabilities of INA were ascribed to Century and extinguished, as a matter of Pennsylvania law, as liabilities of INA.
As part of the Restructuring, most A&E liabilities of various U.S. affiliates of INA were reinsured to Century. Century and certain other run-off companies having A&E and other liabilities were contributed to Brandywine Holdings. ACE acquired Brandywine Holdings and its various subsidiaries as part of the 1999 acquisition of CIGNA's P&C business. For additional information, refer to “Brandywine Run-Off Entities” below.
During 2013, we conducted our annual internal, ground-up review of our consolidated A&E liabilities as of December 31, 2012. As a result of the internal review, we increased our gross unpaid losses and loss expenses in 2013 for the Brandywine operations, including A&E, by $277 million, while the net unpaid losses and loss expenses increased by $166 million. In addition, we increased gross unpaid losses and loss expenses for Westchester Specialty's A&E and other liabilities by $3 million, while the net unpaid losses and loss expenses increased by $5 million.
An internal review was also conducted during 2012 of consolidated A&E liabilities as of December 31, 2011. As a result of that internal review, we increased gross unpaid losses and loss expenses in 2012 for the Brandywine operations, including A&E, by $275 million while the net unpaid losses and loss expenses increased by $146 million. In addition, we increased gross unpaid losses and loss expenses for Westchester Specialty's A&E and other liabilities by $17 million, while the net unpaid losses and loss expenses increased by $4 million.
In 2012, in addition to our annual internal review, a team of external actuaries performed an evaluation as to the adequacy of Century's reserves. This external review was conducted in accordance with the Brandywine Restructuring Order, which requires that an independent actuarial review of Century's reserves be completed every two years. Management takes full responsibility for the estimation of its A&E liabilities.
Brandywine run-off – impact of NICO contracts on ACE's run-off liabilities
As part of the acquisition of CIGNA's P&C business, NICO provided $2.5 billion of reinsurance protection to Century on all Brandywine loss and allocated loss adjustment expense reserves and on the A&E reserves of various ACE INA insurance subsidiaries reinsured by Century (in each case, including uncollectible reinsurance). The benefits of this NICO contract (the Brandywine NICO Agreement) flowed to the other Brandywine companies and to the ACE INA insurance subsidiaries through agreements between those companies and Century. The Brandywine NICO Agreement was exhausted on an incurred basis in 2002 and on a paid basis in 2013.
The following table presents a roll-forward of net loss reserves, allocated loss expense reserves, and provision for uncollectible paid and unpaid reinsurance recoverables in respect of Brandywine operations only, including the impact of the Brandywine NICO Agreement:
	Brandywine													NICO Coverage				Net of NICO Coverage
(in millions of U.S. dollars)	A&E				Other				(1)	Total
Balance at December 31, 2012		$	852			$	421				$	1,273			$	18		$	1,255
Incurred activity		158				9					167				—			167			(2)
Paid activity		(194		)		(63		)			(257		)		(18		)	(239		)
Balance at December 31, 2013		$	816			$	367				$	1,183			$	—		$	1,183
(1)	Other consists primarily of workers' compensation, non-A&E general liability losses, and provision for uncollectible reinsurance on non-A&E business.
(2)	Excludes $(1) million of unallocated loss expenses (benefits).
The incurred activity of $167 million primarily relates to the internal reviews of consolidated A&E loss reserves.
Westchester Specialty – impact of NICO contracts on ACE's run-off liabilities
As part of the Westchester Specialty acquisition in 1998, NICO provided a 75 percent pro-rata share of $1 billion of reinsurance protection on losses and loss adjustment expenses incurred on or before December 31, 1996, in excess of a retention of $721 million. At December 31, 2013, the remaining unused incurred limit under the NICO Agreement was $490 million, which is only available for losses and loss adjustment expenses.
The following table presents a roll-forward of net loss reserves, allocated loss expense reserves, and provision for uncollectible paid and unpaid reinsurance recoverables in respect of 1996 and prior Westchester Specialty operations only, including the impact of the Westchester NICO Agreement:
	Westchester Specialty													NICO Coverage				Net of NICO Coverage
(in millions of U.S. dollars)	A&E				Other					Total
Balance at December 31, 2012		$	151			$	44				$	195			$	158			$	37
Incurred activity		14				(11		)			3				2				1			(1)
Paid activity		-19				—					-19				-19				—
Balance at December 31, 2013		$	146			$	33				$	179			$	141			$	38
-1	Excludes $4 million of unallocated loss expenses.
The incurred activity of $1 million primarily relates to the internal reviews of consolidated A&E loss reserves.
Brandywine run-off entities
In addition to housing a significant portion of ACE's A&E exposure, the Brandywine operations include run-off liabilities related to various insurance and reinsurance businesses. ACE's Brandywine insurance companies are Century (a Pennsylvania insurer) and Century International Reinsurance Company Ltd., a Bermuda insurer (CIRC).  The Brandywine companies are direct or indirect subsidiaries of Brandywine Holdings.
The U.S.-based ACE INA companies assumed two contractual obligations in respect of the Brandywine operations in connection with the Restructuring: a dividend retention fund obligation and a surplus maintenance obligation in the form of the excess of loss (XOL) agreement.
INA Financial Corporation established and funded a dividend retention fund (the Dividend Retention Fund) consisting of $50 million plus investment earnings. Pursuant to an interpretation of the Brandywine Restructuring Order, the full balance of the Dividend Retention Fund was contributed to Century as of December 31, 2002. Under the Restructuring Order, while any obligation to maintain the Dividend Retention Fund is in effect, to the extent dividends are paid by INA Holdings Corporation to its parent, INA Financial Corporation, and to the extent INA Financial Corporation then pays such dividends to INA Corporation, a portion of those dividends must be withheld to replenish the principal of the Dividend Retention Fund to $50 million. Effective January 28, 2011, the Pennsylvania Insurance Department clarified the scope of the Dividend Retention Fund that capital contributions from the Dividend Retention Fund to Century shall not be required until the XOL Agreement has less than $200 million of capacity remaining on an incurred basis for statutory reporting purposes. The amount of the capital contribution shall be the lesser of the amount necessary to restore the XOL Agreement remaining capacity to $200 million or the Dividend Retention Fund balance. The Dividend Retention Fund may not be terminated without prior written approval from the Pennsylvania Insurance Commissioner.
In addition, an ACE INA insurance subsidiary provided reinsurance coverage to Century in the amount of $800 million under an XOL, triggered if the statutory capital and surplus of Century falls below $25 million or if Century lacks liquid assets with which to pay claims as they become due.
Effective December 31, 2004, ACE INA Holdings contributed $100 million to Century in exchange for a surplus note. After giving effect to the contribution and issuance of the surplus note, the statutory surplus of Century at December 31, 2013 was $25 million and approximately $232 million in statutory-basis losses have been ceded to the XOL on an inception-to-date basis. Century reports the amount ceded under the XOL in accordance with statutory accounting principles, which differ from GAAP by, among other things, allowing Century to discount its liabilities, including certain asbestos related and environmental pollution liabilities and Century's reinsurance payable to active companies. For GAAP reporting purposes, intercompany reinsurance recoverables related to the XOL are eliminated upon consolidation.
While ACE believes it has no legal obligation to fund losses above the XOL limit of coverage, ACE's consolidated results would nevertheless continue to include any losses above the limit of coverage for so long as the Brandywine companies remain consolidated subsidiaries of ACE.
Uncertainties relating to ACE's ultimate Brandywine exposure
In addition to the Dividend Retention Fund and XOL commitments described above, certain ACE entities are primarily liable for asbestos, environmental, and other exposures that they have reinsured to Century. Accordingly, if Century were to become insolvent and ACE were to lose control of Century, some or all of the recoverables due to these ACE companies from Century could become uncollectible, yet those ACE entities would continue to be responsible to pay claims to their insureds or reinsureds. At December 31, 2013 and 2012, the aggregate reinsurance balances ceded by the active ACE companies to Century were approximately $929 million and $958 million, respectively. At December 31, 2013 and 2012, Century's carried gross reserves (including reserves ceded by the active ACE companies to Century) were $2.3 billion and $2.1 billion, respectively. ACE believes the intercompany reinsurance recoverables, which relate to liabilities payable over many years, are not impaired. Should Century's loss reserves experience adverse development in the future and should Century be placed into rehabilitation or liquidation, the reinsurance recoverables due from Century to its affiliates would be payable only after the payment in full of certain expenses and liabilities, including administrative expenses and direct policy liabilities. Thus, the intercompany reinsurance recoverables would be at risk to the extent of the shortage of assets remaining to pay these recoverables.

Taxation

Taxation	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Taxation	'
	Taxation
	Under Swiss law, a resident company is subject to income tax at the federal, cantonal, and communal levels that is levied on net worldwide income. Income attributable to permanent establishments or real estate located abroad is excluded from the Swiss tax base. ACE Limited is a holding company and, therefore, is exempt from cantonal and communal income tax. As a result, ACE Limited is subject to Swiss income tax only at the federal level. Furthermore, participation relief (i.e., tax relief) is granted to ACE Limited at the federal level for qualifying dividend income and capital gains related to the sale of qualifying participations (i.e., subsidiaries). It is expected that the participation relief will result in a full exemption of participation income from federal income tax. ACE Limited is resident in the Canton and City of Zurich and, as such, is subject to an annual cantonal and communal capital tax on the taxable equity of ACE Limited in Switzerland.
	ACE has two Swiss operating subsidiaries resident in the Canton and City of Zurich, an insurance company, ACE Insurance (Switzerland) Limited, which, in turn, owns a reinsurance company, ACE Reinsurance (Switzerland) Limited. Both are subject to federal, cantonal, and communal income tax and to annual cantonal and communal capital tax.
	Under current Bermuda law, ACE Limited and its Bermuda subsidiaries are not required to pay any taxes on income or capital gains. If a Bermuda law were enacted that would impose taxes on income or capital gains, ACE Limited and the Bermuda subsidiaries have received an undertaking from the Minister of Finance in Bermuda that would exempt such companies from Bermudian taxation until March 2035.
	Income from ACE's operations at Lloyd's is subject to United Kingdom corporation taxes. Lloyd's is required to pay U.S. income tax on U.S. connected income (U.S. income) written by Lloyd's syndicates. Lloyd's has a closing agreement with the Internal Revenue Service (IRS) whereby the amount of tax due on this business is calculated by Lloyd's and remitted directly to the IRS. These amounts are then charged to the accounts of the Names/Corporate Members in proportion to their participation in the relevant syndicates. ACE's Corporate Members are subject to this arrangement but, as U.K. domiciled companies, will receive U.K. corporation tax credits for any U.S. income tax incurred up to the value of the equivalent U.K. corporation income tax charge on the U.S. income.
	ACE Group Holdings and its respective subsidiaries are subject to income taxes imposed by U.S. authorities and file a consolidated U.S. tax return. Combined Insurance and its life subsidiary will file a separate consolidated U.S. tax return for tax years prior to 2014. Should ACE Group Holdings pay a dividend to ACE, withholding taxes would apply. Currently, however, no withholding taxes are accrued with respect to such un-remitted earnings as management has no intention of remitting these earnings. Similarly, no taxes have been provided on the un-remitted earnings of certain foreign subsidiaries as management has no intention of remitting these earnings. The cumulative amount that would be subject to withholding tax, if distributed, as well as the determination of the associated tax liability are not practicable to compute; however, such amount would be material to ACE. Certain international operations of ACE are also subject to income taxes imposed by the jurisdictions in which they operate.
	ACE is not subject to income taxation other than as stated above.  There can be no assurance that there will not be changes in applicable laws, regulations, or treaties which might require ACE to change the way it operates or becomes subject to taxation.
	ACE's domestic operations are in Switzerland, the jurisdiction where we are legally organized, incorporated, and registered. Domestic operations for the years ended December 31, 2013, 2012, and 2011 are not considered significant to the consolidated income before income taxes for the respective periods.
	The following table presents the provision for income taxes:
		Years Ended December 31
	(in millions of U.S. dollars)	2013			2012			2011
	Current tax expense	$	231		$	305		$	485
	Deferred tax expense (benefit)	249			(35		)	17
	Provision for income taxes	$	480		$	270		$	502
	The most significant jurisdictions contributing to the overall taxation of ACE are calculated using the following rates: Switzerland 7.83 percent, Bermuda 0.0 percent, U.S. 35.0 percent, and U.K. 23.25 percent. The following table presents a reconciliation of the difference between the provision for income taxes and the expected tax provision at the Swiss statutory income tax rate:
		Years Ended December 31
	(in millions of U.S. dollars)	2013			2012			2011
	Expected tax provision at Swiss statutory tax rate	$	331		$	233		$	160
	Permanent differences:
	Taxes on earnings subject to rate other than Swiss statutory rate	124			129			323
	Tax-exempt interest and dividends received deduction, net of proration	(27		)	(24		)	(21		)
	Net withholding taxes	27			23			19
	Favorable resolution of prior years' tax matters and closing statutes of limitations	(5		)	(124		)	—
	Change in valuation allowance	4			4			(2		)
	Other	26			29			23
	Total provision for income taxes	$	480		$	270		$	502
	The following table presents the components of the net deferred tax assets:
		31-Dec			31-Dec
	(in millions of U.S. dollars)	2013			2012
	Deferred tax assets:
	Loss reserve discount	$	807		$	849
	Unearned premiums reserve	93			98
	Foreign tax credits	1,236			1,131
	Investments	3			43
	Provision for uncollectible balances	78			110
	Loss carry-forwards	54			55
	Other	184			110
	Total deferred tax assets	2,455			2,396
	Deferred tax liabilities:
	Deferred policy acquisition costs	138			68
	VOBA and other intangible assets	351			379
	Un-remitted foreign earnings	982			795
	Unrealized appreciation on investments	210			586
	Other	94			59
	Total deferred tax liabilities	1,775			1,887
	Valuation allowance	64			56
	Net deferred tax assets	$	616		$	453
	The valuation allowance of $64 million at December 31, 2013, and $56 million at December 31, 2012, reflects management's assessment, based on available information, that it is more likely than not that a portion of the deferred tax assets will not be realized due to the inability of certain foreign subsidiaries to generate sufficient taxable income and the inability of ACE Group Holdings and its subsidiaries to use foreign tax credits. Adjustments to the valuation allowance are made when there is a change in management's assessment of the amount of deferred tax assets that are realizable.
	At December 31, 2013, ACE has net operating loss carry-forwards of $154 million which, if unused, will expire in the years 2014 through 2033, and a foreign tax credit carry-forward in the amount of $131 million which, if unused, will expire in the years 2015 through 2023.
	The following table presents a reconciliation of the beginning and ending amount of gross unrecognized tax benefits:
		31-Dec			31-Dec
	(in millions of U.S. dollars)	2013			2012
	Balance, beginning of year	$	26		$	134
	Additions based on tax provisions related to the current year	5			19
	Reductions for settlements with tax authorities	—			(16		)
	Reductions for the lapse of the applicable statutes of limitations	(4		)	(111		)
	Balance, end of year	$	27		$	26
	At December 31, 2013 and 2012, the total amount of unrecognized tax benefits that would affect the effective tax rate, if recognized, is $5 million and $8 million, respectively. At December 31, 2013 and 2012, $22 million and $18 million, respectively, of unrecognized tax benefits would not affect the effective tax rate, if recognized, as the ultimate deductibility is highly certain but there is uncertainty about the timing of such deductibility. Because of the impact of deferred tax accounting, other than interest and penalties, an unfavorable resolution of these temporary items would not affect the effective tax rate but would accelerate the payment of cash to the taxing authority to an earlier period.
	ACE recognizes accruals for interest and penalties, if any, related to unrecognized tax benefits in income tax expense in the consolidated statements of operations. Tax-related interest expense (income) and penalties reported in the consolidated statements of operations for the years ended December 31, 2013, 2012, and 2011 were $(1) million, $(8) million, and $3 million, respectively. At December 31, 2013 and 2012, ACE recorded $11 million and $12 million, respectively, in liabilities for tax-related interest and penalties in our consolidated balance sheets.
	In April 2012, ACE reached final settlement with the IRS Appeals Division regarding several issues raised by the IRS Examination Division in its federal tax returns for 2005, 2006, and 2007. The settlement of these issues had no net impact on our results of operations. In addition, the IRS completed its field examination of ACE’s federal tax returns for 2008 and 2009 during June 2012. No material adjustments resulted from this examination. During 2012, ACE recognized a $124 million benefit resulting from the favorable resolution of various prior years' tax matters and the closing of statutes of limitations. During 2013, ACE reduced the amount of unrecognized tax benefits by $5 million resulting from the closing of applicable statutes of limitations. It is reasonably possible that over the next twelve months, the amount of unrecognized tax benefits may change resulting from the re-evaluation of unrecognized tax benefits arising from examinations of taxing authorities and the closing of tax statutes of limitations. With few exceptions, ACE is no longer subject to state and local or non-U.S. income tax examinations for years before 2005.

Debt

Debt	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Debt	'
	Debt
		31-Dec		31-Dec
	(in millions of U.S. dollars)	2013		2012		Early Redemption Option
	Short-term debt
	ACE INA $500 million 5.875% senior notes due June 2014	$	500	$	—	Make-whole premium plus 0.20%
	Repurchase agreements (weighted average interest rate of 0.3% and 0.4%)	1,401		1,401		None
	Total short-term debt	$	1,901	$	1,401
	Long-term debt
	ACE INA senior notes:
	$500 million 5.875% due June 2014	$	—	$	500	Make-whole premium plus 0.20%
	$450 million 5.6% due May 2015	449		449		Make-whole premium plus 0.35%
	$700 million 2.6% due November 2015	700		699		Make-whole premium plus 0.20%
	$500 million 5.7% due February 2017	500		500		Make-whole premium plus 0.20%
	$300 million 5.8% due March 2018	300		300		Make-whole premium plus 0.35%
	$500 million 5.9% due June 2019	500		500		Make-whole premium plus 0.40%
	$475 million 2.7% due March 2023	473		—		Make-whole premium plus 0.10%
	$300 million 6.7% due May 2036	299		299		Make-whole premium plus 0.20%
	$475 million 4.15% due March 2043	474		—		Make-whole premium plus 0.15%
	ACE INA $100 million 8.875% debentures due August 2029	100		100		None
	Other long-term debt (2.75% to 7.1% due December 2019 to September 2020)	12		13		None
	Total long-term debt	$	3,807	$	3,360
	Trust preferred securities
	ACE INA capital securities due April 2030	$	309	$	309	Redemption price(1)
	(1)	Redemption price is equal to accrued and unpaid interest to the redemption date plus the greater of (i) 100 percent of the principal amount thereof, or (ii) sum of present value of scheduled payments of principal and interest on the debentures from the redemption date to April 1, 2030.
	a) Short-term debt
	ACE has executed repurchase agreements with certain counterparties under which ACE agreed to sell securities and repurchase them at a future date for a predetermined price.
	b) Long-term debt
	In March 2013, ACE INA issued $475 million of 2.7 percent senior notes due March 2023 and $475 million of 4.15 percent senior notes due March 2043.
	All of ACE INA’s senior notes are redeemable at any time at ACE INA's option subject to the provisions described above. A “make-whole premium” is the present value of the remaining principal and interest discounted at the applicable U.S. Treasury rate. The senior notes are also redeemable at par plus accrued and unpaid interest in the event of certain changes in tax law. The debentures, subject to certain exceptions, are not redeemable before maturity.
	The senior notes and debentures do not have the benefit of any sinking fund. These senior unsecured notes and debentures are guaranteed on a senior basis by ACE Limited and they rank equally with all of ACE's other senior obligations. They also contain customary limitations on lien provisions as well as customary events of default provisions which, if breached, could result in the accelerated maturity of such senior debt.
	c) ACE INA capital securities
	In March 2000, ACE Capital Trust II, a Delaware statutory business trust, publicly issued $300 million of 9.7 percent Capital Securities (the Capital Securities) due to mature in April 2030. At the same time, ACE INA purchased $9.2 million of common securities of ACE Capital Trust II. The sole assets of ACE Capital Trust II consist of $309 million principal amount of 9.7 percent Junior Subordinated Deferrable Interest Debentures (the Subordinated Debentures) issued by ACE INA due to mature in April 2030.
	Distributions on the Capital Securities are payable semi-annually and may be deferred for up to ten consecutive semi-annual periods (but no later than April 1, 2030). Any deferred payments would accrue interest compounded semi-annually if ACE INA defers interest on the Subordinated Debentures. Interest on the Subordinated Debentures is payable semi-annually. ACE INA may defer such interest payments (but no later than April 1, 2030), with such deferred payments accruing interest compounded semi-annually. The Capital Securities and the ACE Capital Trust II Common Securities will be redeemed upon repayment of the Subordinated Debentures.
	ACE Limited has guaranteed, on a subordinated basis, ACE INA's obligations under the Subordinated Debentures, and distributions and other payments due on the Capital Securities. These guarantees, when taken together with ACE's obligations under expense agreements entered into with ACE Capital Trust II, provide a full and unconditional guarantee of amounts due on the Capital Securities.

Commitments_contingencies_and_

Commitments, contingencies, and guarantees	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments, contingencies, and guarantees	'
	Commitments, contingencies, and guarantees
	a) Derivative instruments
	Derivative instruments employed
	ACE maintains positions in derivative instruments such as futures, options, swaps, and foreign currency forward contracts for which the primary purposes are to manage duration and foreign currency exposure, yield enhancement, or to obtain an exposure to a particular financial market. ACE also maintains positions in convertible bond investments that contain embedded derivatives. These are the most numerous and frequent derivative transactions.
	In addition, ACE from time to time purchases to be announced mortgage-backed securities (TBAs) as part of its investing activities.
	Under reinsurance programs covering GLBs, ACE assumes the risk of GLBs, including GMIB and GMAB, associated with variable annuity contracts. The GMIB risk is triggered if, at the time the contract holder elects to convert the accumulated account value to a periodic payment stream (annuitize), the accumulated account value is not sufficient to provide a guaranteed minimum level of monthly income. The GMAB risk is triggered if, at contract maturity, the contract holder’s account value is less than a guaranteed minimum value. The GLB reinsurance product meets the definition of a derivative instrument. Benefit reserves in respect of GLBs are classified as Future policy benefits (FPB) while the fair value derivative adjustment is classified within Accounts payable, accrued expenses, and other liabilities (AP). ACE also maintains positions in exchange-traded equity futures contracts and options on equity market indices to limit equity exposure in the GMDB and GLB blocks of business.
	In relation to certain debt issuances, ACE from time to time enters into interest rate swap transactions for the purpose of either fixing or reducing borrowing costs. Although the use of these interest rate swaps has the economic effect of fixing or reducing borrowing costs on a net basis, gross interest expense on the related debt issuances is included in Interest expense while the settlements related to the interest rate swaps are reflected in Net realized gains (losses) in the consolidated statements of operations. At December 31, 2013, ACE had no in-force interest rate swaps.
	ACE from time to time buys credit default swaps to mitigate global credit risk exposure, primarily related to reinsurance recoverables. At December 31, 2013, ACE had no in-force credit default swaps.
	All derivative instruments are carried at fair value with changes in fair value recorded in Net realized gains (losses) in the consolidated statements of operations. None of the derivative instruments are designated as hedges for accounting purposes.
	The following table presents the balance sheet locations, fair values of derivative instruments in an asset or (liability) position, and notional values/payment provisions of our derivative instruments:
		31-Dec-13													31-Dec-12
		Consolidated		Fair Value								Notional		Consolidated	Fair Value					Notional
		Balance Sheet										Value/		Balance Sheet						Value/
		Location(1)		Derivative Asset				Derivative (Liability)				Payment		Location	Derivative Asset		Derivative (Liability)			Payment
	(in millions of U.S. dollars)											Provision								Provision
	Investment and embedded derivative instruments
	Foreign currency forward contracts	OA / (AP)		$	3			$	(4	)		$	1,202	AP	$	—	$	—		$	620
	Cross-currency swaps	OA / (AP)		—				—				50		AP	—		—			50
	Futures contracts on money market instruments	OA / (AP)		3				—				3,910		AP	1		—			2,710
	Futures contracts on notes and bonds	OA / (AP)		13				(2		)		871		AP	10		—			915
	Convertible bonds	FM AFS		302				—				254		FM AFS	309		—			279
				$	321			$	(6	)		$	6,287		$	320	$	—		$	4,574
	Other derivative instruments
	Futures contracts on equities(2)	OA / (AP)		$	—			$	(60	)		$	1,692	AP	$	—	$	(6	)	$	2,308
	Options on equity market indices(2)	OA / (AP)		6				—				250		AP	30		—			250
	Other	OA / (AP)		—				(2		)		8		AP	—		—			—
				$	6			$	(62	)		$	1,950		$	30	$	(6	)	$	2,558
	GLB(3)	(AP) / (FPB)		$	—			$	(427	)		$	277	AP / FPB	$	—	$	(1,352	)	$	1,100
	-1	Other assets (OA), Fixed maturities available for sale (FM AFS)
	(2)	Related to GMDB and GLB blocks of business.
	(3)	Includes both future policy benefits reserves and fair value derivative adjustment. Refer to Note 5 c) for additional information. Note that the payment provision related to GLB is the net amount at risk. The concept of a notional value does not apply to the GLB reinsurance contracts.
	On January 1, 2013, we adopted new accounting guidance that requires disclosure of financial instruments subject to a master netting agreement.  At December 31, 2013 and December 31, 2012, derivative liabilities of $41 million and derivative assets of $35 million, respectively, included in the table above were subject to a master netting agreement.  The remaining derivatives included in the table above were not subject to a master netting agreement.
	At both December 31, 2013 and 2012, our repurchase obligations of $1,401 million were fully collateralized.  At December 31, 2013 and 2012, our securities lending payable was $1,633 million and $1,795 million, respectively, and our securities lending collateral was $1,632 million and $1,791 million, respectively.  The securities lending collateral can only be accessed in the event that the institution borrowing the securities is in default under the lending agreement.  An indemnification agreement with the lending agent protects us in the event a borrower becomes insolvent or fails to return any of the securities on loan.  In contrast to securities lending programs, the use of cash received is not restricted for the repurchase obligations.
	The following table presents net realized gains (losses) related to derivative instrument activity in the consolidated statements of operations:
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012				2011
	Investment and embedded derivative instruments
	Foreign currency forward contracts	$	11			$	(9	)		$	6
	All other futures contracts and options	61				(22		)		(98		)
	Convertible bonds	6				25				(50		)
	TBAs	—				—				(1		)
	Total investment and embedded derivative instruments	$	78			$	(6	)		$	(143	)
	GLB and other derivative instruments
	GLB(1)	$	878			$	171			$	(779	)
	Futures contracts on equities(2)	(555		)		(273		)		(12		)
	Options on equity market indices(2)	(24		)		(24		)		8
	Other	(2		)		(4		)		(4		)
	Total GLB and other derivative instruments	$	297			$	(130	)		$	(787	)
		$	375			$	(136	)		$	(930	)
	(1)	Excludes foreign exchange gains (losses) related to GLB.
	(2)	Related to GMDB and GLB blocks of business.
	Derivative instrument objectives
	(i) Foreign currency exposure management
	A foreign currency forward contract (forward) is an agreement between participants to exchange specific foreign currencies at a future date. ACE uses forwards to minimize the effect of fluctuating foreign currencies.
	(ii) Duration management and market exposure
	Futures
	Futures contracts give the holder the right and obligation to participate in market movements, determined by the index or underlying security on which the futures contract is based. Settlement is made daily in cash by an amount equal to the change in value of the futures contract times a multiplier that scales the size of the contract. Exchange-traded futures contracts on money market instruments, notes and bonds are used in fixed maturity portfolios to more efficiently manage duration, as substitutes for ownership of the money market instruments, bonds and notes without significantly increasing the risk in the portfolio. Investments in futures contracts may be made only to the extent that there are assets under management not otherwise committed.
	Exchange-traded equity futures contracts are used to limit exposure to a severe equity market decline, which would cause an increase in expected claims and therefore, reserves for GMDB and GLB reinsurance business.
	Options
	An option contract conveys to the holder the right, but not the obligation, to purchase or sell a specified amount or value of an underlying security at a fixed price. Option contracts are used in the investment portfolio as protection against unexpected shifts in interest rates, which would affect the duration of the fixed maturity portfolio. By using options in the portfolio, the overall interest rate sensitivity of the portfolio can be reduced. Option contracts may also be used as an alternative to futures contracts in the synthetic strategy as described above.
	Another use for option contracts is to limit exposure to a severe equity market decline, which would cause an increase in expected claims and therefore, reserves for GMDB and GLB reinsurance business.
	The price of an option is influenced by the underlying security, expected volatility, time to expiration, and supply and demand.
	The credit risk associated with the above derivative financial instruments relates to the potential for non-performance by counterparties. Although non-performance is not anticipated, in order to minimize the risk of loss, management monitors the creditworthiness of its counterparties and obtains collateral. The performance of exchange-traded instruments is guaranteed by the exchange on which they trade. For non-exchange-traded instruments, the counterparties are principally banks which must meet certain criteria according to our investment guidelines.
Cross-currency swaps
Cross-currency swaps are agreements under which two counterparties exchange interest payments and principal denominated in different currencies at a future date.  We use cross-currency swaps to reduce the foreign currency and interest rate risk by converting cash flows back into local currency.  We invest in foreign currency denominated investments to improve credit diversification and also to obtain better duration matching to our liabilities that is limited in the local currency market.
Other
Included within Other are derivatives intended to reduce potential losses which may arise from certain exposures in our insurance business.  The economic benefit provided by these derivatives is similar to purchased reinsurance.  For example, from time to time ACE may enter into derivative contracts to protect underwriting results in the event of a significant decline in commodity prices.  Also included within Other are credit default swaps purchased and certain life insurance products that meet the definition of a derivative instrument for accounting purposes.
(iii) Convertible security investments
A convertible bond is a debt instrument that can be converted into a predetermined amount of the issuer’s equity at certain times prior to the bond’s maturity. The convertible option is an embedded derivative within the fixed maturity host instruments which are classified in the investment portfolio as available for sale. ACE purchases convertible bonds for their total return and not specifically for the conversion feature.
(iv) TBA
By acquiring TBAs, we make a commitment to purchase a future issuance of mortgage-backed securities. For the period between purchase of the TBAs and issuance of the underlying security, we account for our position as a derivative in the consolidated financial statements. ACE purchases TBAs both for their total return and for the flexibility they provide related to our mortgage-backed security strategy.
(v) GLB
Under the GLB program, as the assuming entity, ACE is obligated to provide coverage until the expiration or maturity of the underlying deferred annuity contracts or the expiry of the reinsurance treaty. Premiums received under the reinsurance treaties are classified as premium. Expected losses allocated to premiums received are classified as Future policy benefits and valued similar to GMDB reinsurance. Other changes in fair value, principally arising from changes in expected losses allocated to expected future premiums, are classified as Net realized gains (losses). Fair value represents management’s estimate of exit price and thus, includes a risk margin. We may recognize a realized loss for other changes in fair value due to adverse changes in the capital markets (e.g., declining interest rates and/or declining equity markets) and changes in actual or estimated future policyholder behavior (e.g., increased annuitization or decreased lapse rates) although we expect the business to be profitable. We believe this presentation provides the most meaningful disclosure of changes in the underlying risk within the GLB reinsurance programs for a given reporting period.
b) Concentrations of credit risk
Our investment portfolio is managed following prudent standards of diversification. Specific provisions limit the allowable holdings of a single issue and issuer. We believe that there are no significant concentrations of credit risk associated with our investments. Our three largest exposures by issuer at December 31, 2013, were JP Morgan Chase & Co., Goldman Sachs Group Inc., and General Electric Company. Our largest exposure by industry at December 31, 2013 was financial services.
We market our insurance and reinsurance worldwide primarily through insurance and reinsurance brokers. We assume a degree of credit risk associated with brokers with whom we transact business. During both years ended December 31, 2013 and 2012, and in the year ended December 31, 2011, approximately 11 percent and 12 percent, respectively, of our gross premiums written were generated from or placed by Marsh, Inc. This entity is a large, well established company and there are no indications that it is financially troubled at December 31, 2013. In addition, during the year ended December 31, 2011, approximately 10 percent of our gross premiums written were generated from or placed by Aon Corporation and its affiliates. No other broker and no one insured or reinsured accounted for more than 10 percent of gross premiums written in the years ended December 31, 2013, 2012, and 2011.
c) Other investments
At December 31, 2013, included in Other investments in the consolidated balance sheet are investments in limited partnerships and partially-owned investment companies with a carrying value of $1.9 billion. In connection with these investments, we have commitments that may require funding of up to $1.2 billion over the next several years.
d) Letters of credit
We have a $1.0 billion unsecured operational LOC facility (adjustable to $1.5 billion upon consent of the issuers) expiring in November 2017. We are allowed to use up to $300 million of this LOC facility as an unsecured revolving credit facility. At December 31, 2013, outstanding LOCs issued under this facility were $376 million. We also have a $500 million unsecured operational LOC facility expiring in June 2014. At December 31, 2013, this facility was fully utilized.
To satisfy funding requirements of ACE's Lloyd's Syndicate 2488 through 2014, we have a series of four bilateral uncollateralized LOC facilities totaling $425 million. LOCs issued under these facilities will expire no earlier than December 2017. Usage of this facility at December 31, 2013 was $352 million.
These facilities require that ACE Limited and/or certain of its subsidiaries continue to maintain certain covenants. ACE Limited is also required to maintain a minimum consolidated net worth covenant and a maximum leverage covenant, which have been met at December 31, 2013.
e) Legal proceedings
Our insurance subsidiaries are subject to claims litigation involving disputed interpretations of policy coverages and, in some jurisdictions, direct actions by allegedly-injured persons seeking damages from policyholders. These lawsuits, involving claims on policies issued by our subsidiaries which are typical to the insurance industry in general and in the normal course of business, are considered in our loss and loss expense reserves. In addition to claims litigation, we are subject to lawsuits and regulatory actions in the normal course of business that do not arise from or directly relate to claims on insurance policies. This category of business litigation typically involves, among other things, allegations of underwriting errors or misconduct, employment claims, regulatory activity, or disputes arising from our business ventures. In the opinion of management, our ultimate liability for these matters could be, but we believe is not likely to be, material to our consolidated financial condition and results of operations.
f) Lease commitments
We lease office space and equipment under operating leases which expire at various dates through 2033. Rent expense was $128 million, $112 million, and $114 million for the years ended December 31, 2013, 2012, and 2011, respectively. Future minimum lease payments under the leases are expected to be as follows:
For the year ending December 31
(in millions of U.S. dollars)
2014	$	106
2015	99
2016	86
2017	70
2018	49
Thereafter	124
Total minimum future lease commitments	$	534

Shareholders_equity

Shareholders' equity	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Note [Abstract]	'
Shareholders' equity	'
	Shareholders’ equity
	a) Common Shares
	All of ACE’s Common Shares are authorized under Swiss corporate law. Though the par value of Common Shares is stated in Swiss francs, ACE continues to use U.S. dollars as its reporting currency for preparing the consolidated financial statements. Under Swiss corporate law, we are generally prohibited from issuing Common Shares below their par value. If there were a need to raise common equity at a time when the trading price of ACE's Common Shares is below par value, we would need in advance to obtain shareholder approval to decrease the par value of the Common Shares.
	At our May 2012 and 2013 Annual General Meetings, our shareholders approved a dividend for the following years, respectively, payable in four quarterly installments after the annual general meetings in the form of a distribution by way of a par value reduction. At the January 10, 2014 Extraordinary General Meeting, our shareholders approved a resolution to increase our quarterly dividend from $0.51 per share to $0.63 per share for the final two quarterly installments (made on January 31, 2014 and the payment to be made by the end of April 2014) that had been earlier approved at our 2013 annual general meeting. The $0.12 per share increase for each installment will be distributed from capital contribution reserves while the existing $0.51 per share will be distributed by way of a par value reduction.
	Under Swiss corporate law, dividends, including distributions through a reduction in par value (par value reduction), must be stated in Swiss francs though dividend payments are made by ACE in U.S. dollars. Dividend distributions following ACE's redomestication to Switzerland have generally been made by way of par value reduction (under the methods approved by our shareholders at our Annual General Meetings) and had the effect of reducing par value per Common Share each time a dividend was distributed. In light of a January 1, 2011 Swiss tax law change, we may also issue dividends without subjecting them to withholding tax by way of distributions from capital contribution reserves (Additional paid-in capital), a subaccount of legal reserves, and paid out of free reserves (Retained earnings). We employed this method of dividends during portions of 2011 and 2012, and to effect our dividend increase that was approved by shareholders on January 10, 2014.
	b) Shares issued, outstanding, authorized, and conditional
		Years Ended December 31
		2013		2012		2011
	Shares issued, beginning of year	342,832,412		342,832,412		341,094,559
	Exercise of stock options	—		—		1,737,853
	Shares issued, end of year	342,832,412		342,832,412		342,832,412
	Common Shares in treasury, end of year (at cost)	(3,038,477	)	(2,510,878	)	(5,905,136	)
	Shares issued and outstanding, end of year	339,793,935		340,321,534		336,927,276
	Common Shares issued to employee trust
	Balance, beginning of year	(9,467	)	(9,467	)	(101,481	)
	Shares redeemed	—		—		92,014
	Balance, end of year	(9,467	)	(9,467	)	(9,467	)
	Prior to August 2011, exercises of stock options were satisfied through newly issued shares. From August 2011 onward, exercises of stock options were satisfied through Common Shares in treasury. Other decreases in Common Shares in treasury are principally due to grants of restricted stock, and purchases under the Employee Stock Purchase Plan (ESPP). Increases in Common Shares in treasury are due to open market repurchases of Common Shares and the surrender of Common Shares to satisfy tax withholding obligations in connection with the vesting of restricted stock and the forfeiture of unvested restricted stock.
	For the years ended December 31, 2013, 2012, and 2011, ACE repurchased 3,266,531 Common Shares, 100,000 Common Shares, and 2,058,860 Common Shares in a series of open market transactions, respectively. The cost of these shares, which were placed in treasury, totaled $290 million, $7 million, and $132 million for the years ended December 31, 2013, 2012, and 2011, respectively. ACE repurchased these Common Shares to partially offset potential dilution from the exercise of stock options and the granting of restricted stock under share-based compensation plans as well as part of an overall capital management strategy.
	Common Shares issued to employee trust are issued by ACE to a rabbi trust for deferred compensation obligations as discussed in Note 11 f) below.
	Authorized share capital for general purposes
	The ACE Limited Board of Directors (Board) has shareholder-approved authority as set forth in the Articles of Association to increase for general purposes ACE's share capital from time to time through May 16, 2014, by the issuance of up to 140,000,000 fully paid up Common Shares, with a par value equal to the par value of ACE's Common Shares as set forth in the Articles of Association at the time of any such issuance.
	Conditional share capital for bonds and similar debt instruments
	The share capital of ACE may be increased through the issuance of a maximum of 33,000,000 fully paid up Common Shares (with a par value of CHF 27.04 as of December 31, 2013) through the exercise of conversion and/or option or warrant rights granted in connection with bonds, notes, or similar instruments, issued or to be issued by ACE, including convertible debt instruments.
	Conditional share capital for employee benefit plans
	The share capital of ACE may be increased through the issuance of a maximum of 25,410,929 fully paid up Common Shares (with a par value of CHF 27.04 as of December 31, 2013) in connection with the exercise of option rights granted to any employee of ACE, and any consultant, director, or other person providing services to ACE.
	c) ACE Limited securities repurchase authorization
	On November 21, 2013, the Board announced authorization of a share repurchase program of up to $2 billion of ACE's Common Shares through December 31, 2014.  This $2 billion authorization replaces the previous authorizations which had a remaining balance of $228 million and expired on December 31, 2013. Such repurchases may be made in the open market, in privately negotiated transactions, block trades, accelerated repurchases and/or through option or other forward transactions. At December 31, 2013, $1.94 billion in share repurchase authorization remained through December 31, 2014 pursuant to the Board authorization. For the period January 1, 2014 through February 27, 2014, ACE repurchased 3,437,082 Common Shares for a total of $326 million in a series of open market transactions. At February 27, 2014, $1.62 billion in share repurchase authorization remained through December 31, 2014.
	d) General restrictions
	The holders of the Common Shares are entitled to receive dividends as approved by the shareholders. Holders of Common Shares are allowed one vote per share provided that, if the controlled shares of any shareholder constitute ten percent or more of the outstanding Common Shares of ACE, only a fraction of the vote will be allowed so as not to exceed ten percent in aggregate. Entry of acquirers of Common Shares as shareholders with voting rights in the share register may be refused if it would confer voting rights with respect to ten percent or more of the registered share capital recorded in the commercial register.
	e) Dividends
	Refer to section a) above for a discussion on the methods of dividend payments. Dividend distributions on Common Shares amounted to CHF 1.85 ($2.02) per Common Share (paid through par value reductions), CHF 1.91 ($2.06) per Common Share (including par value reductions of CHF 1.38 per Common Share), and CHF 1.22 ($1.38) per Common Share (including a par value reduction of CHF 0.30 per Common Share) for the years ended December 31, 2013, 2012, and 2011, respectively. Par value reductions have been reflected as such through Common Shares in the consolidated statements of shareholders' equity. The par value per Common Share at December 31, 2013, was CHF 27.04.
	f) Deferred compensation obligation
	ACE maintains rabbi trusts for deferred compensation plans principally for employees and former directors. The shares issued by ACE to the rabbi trusts in connection with deferrals of share compensation are classified in shareholders' equity and accounted for at historical cost in a manner similar to Common Shares in treasury. These shares are recorded in Common Shares issued to employee trust and the obligations are recorded in Deferred compensation obligation in the consolidated balance sheets. Changes in the fair value of the shares underlying the obligations are recorded in Accounts payable, accrued expenses, and other liabilities in the consolidated balance sheets and the related expense or income is recorded in Administrative expenses in the consolidated statements of operations.
	The rabbi trusts also hold other assets, such as fixed maturities, equity securities, and life insurance policies. The assets of the rabbi trusts are consolidated with ACE's assets in the consolidated balance sheets. Assets held by the trust and the associated obligations are reported at fair value in Other investments and Accounts payable, accrued expenses, and other liabilities, respectively, in the consolidated balance sheets, with changes in fair value reflected as a corresponding increase or decrease to Other (income) expense in the consolidated statements of operations. However, life insurance policies assets and obligations are reported at cash surrender value.

Sharebased_compensation

Share-based compensation	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share-based compensation	'
	Share-based compensation
	ACE has share-based compensation plans which currently provide the Board the ability to grant awards of stock options, restricted stock, and restricted stock units to its employees, consultants, and members of the Board.
	ACE principally issues restricted stock grants and stock options on a graded vesting schedule. ACE recognizes compensation cost for restricted stock and stock option grants with only service conditions that have a graded vesting schedule on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in-substance, multiple awards. We incorporate an estimate of future forfeitures (6.5 percent assumption used for 2013, 2012, and 2011) into the determination of compensation cost for both grants of restricted stock and stock options.
	During 2004, we established the ACE Limited 2004 Long-Term Incentive Plan (the 2004 LTIP), which replaced our prior incentive plans except for outstanding awards. The 2004 LTIP will continue in effect until terminated by the Board. Under the 2004 LTIP, Common Shares of ACE are authorized to be issued pursuant to awards made as stock options, stock appreciation rights, performance shares, performance units, restricted stock, and restricted stock units.
	ACE generally grants restricted stock and restricted stock units with a 4-year vesting period, based on a graded vesting schedule. The restricted stock is granted at market close price on the day of grant. Each restricted stock unit represents our obligation to deliver to the holder one Common Share upon vesting.
	In May 2013, our shareholders approved an increase of eight million shares authorized to be issued under the 2004 LTIP, bringing the total shares authorized (i.e., for grant since its inception) to the sum of: (i) 38,600,000 common shares; and (ii) any shares that are represented by awards granted under the prior plans that are forfeited, expired, or are canceled after the effective date of the 2004 LTIP, without delivery of shares or which result in the forfeiture of the shares back to ACE to the extent that such shares would have been added back to the reserve under the terms of the applicable prior plan. At December 31, 2013, a total of 11,231,423 shares remain available for future issuance under the 2004 LTIP.
	In May 2012, our shareholders approved an increase of 1,500,000 shares authorized to be issued under the ESPP bringing the total shares authorized to 4,500,000 shares.  At December 31, 2013, a total of 1,313,586 shares remain available for issuance under the ESPP.
	ACE generally issues Common Shares for the exercise of stock options, restricted stock, and purchases under the ESPP from un-issued reserved shares (conditional share capital) and Common Shares in treasury.
	The following table presents pre-tax and after-tax share-based compensation expense:
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012			2011
	Stock options and shares issued under ESPP:
	Pre-tax	$	24			$	22		$	23
	After-tax (1)	$	18			$	17		$	17
	Restricted stock:
	Pre-tax	$	153			$	109		$	108
	After-tax	$	89			$	64		$	70
	(1)	Excludes windfall tax benefit for share-based compensation recognized as a direct adjustment to Additional paid-in capital of $36 million, $18 million and $6 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	Unrecognized compensation expense related to the unvested portion of ACE's employee share-based awards was $107 million at December 31, 2013, and is expected to be recognized over a weighted-average period of approximately 1 year.
	Stock options
	ACE's 2004 LTIP permits grants of both incentive and non-qualified stock options principally at an option price per share equal to the grant date fair value of ACE's Common Shares. Stock options are generally granted with a 3-year vesting period and a 10-year term. Stock options vest in equal annual installments over the respective vesting period, which is also the requisite service period.
	ACE's 2013 share-based compensation expense includes a portion of the cost related to the 2010 through 2013 stock option grants. Stock option fair value was estimated on the grant date using the Black-Scholes option-pricing model that uses the weighted-average assumptions noted below:
		Years Ended December 31
		2013		2012		2011
	Dividend yield	2.4	%	2.7	%	2.2	%
	Expected volatility	27.8	%	29.8	%	28.8	%
	Risk-free interest rate	1	%	1.1	%	2.3	%
	Expected life	5.8 years		5.8 years		5.4 years
	The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant. The expected life (estimated period of time from grant to exercise date) was estimated using the historical exercise behavior of employees. Expected volatility was calculated as a blend of (a) historical volatility based on daily closing prices over a period equal to the expected life assumption, (b) long-term historical volatility based on daily closing prices over the period from ACE's initial public trading date through the most recent quarter, and (c) implied volatility derived from ACE's publicly traded options.
	The following table presents a roll-forward of ACE's stock options:
	(Intrinsic Value in millions of U.S. dollars)	Number of Options			Weighted-Average Exercise Price			Weighted-Average Fair Value			Total Intrinsic Value
	Options outstanding, December 31, 2010	11,942,893			$	46.8
	Granted	1,649,824			$	62.68		$	14.67
	Exercised	(2,741,238	)		$	44.45					$	63
	Forfeited	(271,972	)		$	51.33
	Options outstanding, December 31, 2011	10,579,507			$	49.78
	Granted	1,462,103			$	73.36		$	15.58
	Exercised	(2,401,869	)		$	42.5					$	78
	Forfeited	(190,082	)		$	61.87
	Options outstanding, December 31, 2012	9,449,659			$	55.03
	Granted	1,821,063			$	85.41		$	17.29
	Exercised	(1,658,671	)		$	48.17					$	70
	Forfeited	(115,195	)		$	72.5
	Options outstanding, December 31, 2013	9,496,856			$	61.84					$	396
	Options exercisable, December 31, 2013	6,330,456			$	53.52					$	317
	The weighted-average remaining contractual term was 6.5 years for stock options outstanding and 4.8 years for stock options exercisable at December 31, 2013. Cash received from the exercise of stock options for the year ended December 31, 2013 was $85 million.
	Restricted stock and restricted stock units
	Grants of restricted stock and restricted stock units granted under the 2004 LTIP typically have a 4-year vesting period, based on a graded vesting schedule. ACE also grants restricted stock awards to non-management directors which vest at the following year's annual general meeting. The restricted stock is granted at market close price on the grant date. Each restricted stock unit represents our obligation to deliver to the holder one Common Share upon vesting. ACE's 2013 share-based compensation expense includes a portion of the cost related to the restricted stock granted in the years 2009 through 2013.
	The following table presents a roll-forward of our restricted stock awards. Included in the roll-forward below are 20,969 restricted stock awards, 25,669 restricted stock awards, and 32,660 restricted stock awards that were granted to non-management directors during the years ended December 31, 2013, 2012, and 2011 respectively:
		Number of Restricted Stock			Weighted-Average Grant-Date Fair Value
	Unvested restricted stock, December 31, 2010	5,305,732			$	48.74
	Granted	1,808,745			$	60.01
	Vested	(1,929,189	)		$	50.82
	Forfeited	(333,798	)		$	47.46
	Unvested restricted stock, December 31, 2011	4,851,490			$	52.2
	Granted	1,589,178			$	73.46
	Vested	(1,923,385	)		$	52.71
	Forfeited	(262,436	)		$	58.4
	Unvested restricted stock, December 31, 2012	4,254,847			$	59.53
	Granted	1,544,485			$	86.07
	Vested	(1,951,494	)		$	57.44
	Forfeited	(139,651	)		$	67.72
	Unvested restricted stock, December 31, 2013	3,708,187			$	71.38
During the years ended December 31, 2013, 2012, and 2011, ACE awarded 271,004 restricted stock units, 262,549 restricted stock units, and 261,214 restricted stock units, respectively, to employees and officers each with a weighted-average grant date fair value per share of $85.44, $73.41, and $62.85, respectively. At December 31, 2013, there were 617,893 unvested restricted stock units.
Prior to 2009, ACE granted restricted stock units with a 1-year vesting period to non-management directors. Delivery of Common Shares on account of these restricted stock units to non-management directors is deferred until after the date of the non-management directors' termination from the Board. At December 31, 2013, there were 196,622 deferred restricted stock units.
ESPP
The ESPP gives participating employees the right to purchase Common Shares through payroll deductions during consecutive subscription periods at a purchase price of 85 percent of the fair value of a Common Share on the exercise date (Purchase Price). Annual purchases by participants are limited to the number of whole shares that can be purchased by an amount equal to ten percent of the participant's compensation or $25,000, whichever is less. The ESPP has two six-month subscription periods each year, the first of which runs between January 1 and June 30 and the second of which runs between July 1 and December 31. The amounts collected from participants during a subscription period are used on the exercise date to purchase full shares of Common Shares. An exercise date is generally the last trading day of a subscription period. The number of shares purchased is equal to the total amount, at the exercise date, collected from the participants through payroll deductions for that subscription period, divided by the Purchase Price, rounded down to the next full share. Participants may withdraw from an offering before the exercise date and obtain a refund of amounts withheld through payroll deductions. Pursuant to the provisions of the ESPP, during the years ended December 31, 2013, 2012, and 2011, employees paid $14 million, $13 million, and $12 million to purchase 175,437 shares, 198,244 shares, and 205,812 shares, respectively.

Pension_plans

Pension plans	12 Months Ended
	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
Pension plans	'
	Pension plans
	ACE provides pension benefits to eligible employees and their dependents through various defined contribution plans and defined benefit plans sponsored by ACE. The defined contribution plans include a capital accumulation plan (401(k)) in the U.S. The defined benefit plans consist of various plans offered in certain jurisdictions primarily outside of the U.S. and Bermuda.
	Defined contribution plans (including 401(k))
	Under these plans, employees' contributions may be supplemented by ACE matching contributions based on the level of employee contribution. These contributions are invested at the election of each employee in one or more of several investment portfolios offered by a third-party investment advisor. Expenses for these plans totaled $111 million, $99 million, and $96 million for the years ended December 31, 2013, 2012, and 2011, respectively.
	Defined benefit plans
	We maintain non-contributory defined benefit plans that cover certain employees, principally located in Europe, Asia, and Mexico. We also provide a defined benefit plan to certain U.S.-based employees as a result of our acquisition of Penn Millers in November 2011. We account for pension benefits using the accrual method. Benefits under these plans are based on employees' years of service and compensation during final years of service. All underlying defined benefit plans are subject to periodic actuarial valuation by qualified local actuarial firms using actuarial models in calculating the pension expense and liability for each plan. We use December 31 as the measurement date for our defined benefit pension plans.
	Components of accrued pension liability (included in Accounts payable, accrued expenses, and other liabilities in the consolidated balance sheets):
		31-Dec		31-Dec
	(in millions of U.S dollars)	2013		2012
	Fair value of plan assets	$	566	$	487
	Projected benefit obligation	591		531
	Accrued pension liability	$	25	$	44
	The defined benefit pension plan contribution for 2014 is expected to be $3 million. The estimated net actuarial loss for the defined benefit pension plans that will be amortized from AOCI into net benefit costs over the next year is $3 million.
	Benefit payments were $26 million and $37 million for the years ended December 31, 2013 and 2012, respectively. Benefit payments for the year ended December 31, 2012 included $12 million related to the full settlement of a defined benefit plan. Expected future payments are as follows:
	For the year ending December 31
	(in millions of U.S dollars)
	2014	$	19
	2015	22
	2016	23
	2017	22
	2018	23
	2019-2023	129

Other_income_expense

Other (income) expense	12 Months Ended
	Dec. 31, 2013
Other Income and Expenses [Abstract]	'
Other (income) expense	'
	Other (income) expense
		Years Ended December 31
	(in millions of U.S. dollars)	2013			2012			2011
	Amortization of intangible assets	$	95		$	51		$	29
	Equity in net (income) loss of partially-owned entities	(119		)	(80		)	(32		)
	(Gains) losses from fair value changes in separate account assets	(16		)	(29		)	36
	Federal excise and capital taxes	24			22			20
	Acquisition-related costs	4			11			5
	Other	27			19			23
	Other (income) expense	$	15		$	(6	)	$	81
	Other (income) expense includes Amortization of intangible assets, which is higher in 2013 due primarily to the acquisitions of Fianzas Monterrey (completed April 1, 2013) and ABA Seguros (completed May 2, 2013). Equity in net (income) loss of partially-owned entities includes our share of net (income) loss related to investment funds, limited partnerships, partially-owned investment companies, and partially-owned insurance companies. Also included in Other (income) expense are (Gains) losses from fair value changes in separate account assets that do not qualify for separate account reporting under GAAP. The offsetting movement in the separate account liabilities is included in Policy benefits in the consolidated statements of operations. Certain federal excise and capital taxes incurred as a result of capital management initiatives are included in Other (income) expense as these are considered capital transactions and are excluded from underwriting results.

Segment_information

Segment information	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Segment information	'
	Segment information
	ACE operates through five business segments: Insurance – North American P&C, Insurance – North American Agriculture, Insurance – Overseas General, Global Reinsurance, and Life. These segments distribute their products through various forms of brokers, agencies, and direct marketing programs. All business segments have established relationships with reinsurance intermediaries.
	Effective January 1, 2013, the former Insurance – North American segment is presented in two distinct reportable segments:
	Insurance – North American P&C and Insurance – North American Agriculture. Prior year amounts contained in this report have
	been adjusted to conform to the new segment presentation.
	The Insurance – North American P&C segment comprises our operations in the U.S., Canada, and Bermuda. This segment includes the operations of ACE USA (including ACE Canada), ACE Commercial Risk Services, ACE Private Risk Services, ACE Westchester, ACE Bermuda, and various run-off operations, including Brandywine. ACE USA is the North American retail operating division which provides a broad array of traditional and specialty P&C, A&H, and risk management products and services to a diverse group of North America commercial and non-commercial enterprises and consumers. ACE Commercial Risk Services addresses the insurance needs of small and mid-sized businesses in North America by delivering a broad array of specialty product solutions for targeted industries that lend themselves to technology-assisted underwriting. ACE Private Risk Services provides high-value personal lines coverages for high net worth individuals and families in North America. ACE Westchester focuses on the North American wholesale distribution of excess and surplus lines property, casualty, environmental, professional liability and inland marine products. ACE Bermuda provides commercial insurance products on an excess basis mainly to a global client base targeting Fortune 1000 companies and covering exposures that are generally low in frequency and high in severity. The run-off operations do not actively sell insurance products but are responsible for the management of certain existing policies and settlement of related claims.
	The Insurance – North American Agriculture segment comprises our North American based businesses that provide a variety of coverages in the U.S. and Canada including crop insurance, primarily Multiple Peril Crop Insurance (MPCI) and crop-hail through Rain and Hail Insurance Services, Inc. as well as farm and ranch, and specialty P&C commercial insurance products and services through our ACE Agribusiness unit. The MPCI program is offered in conjunction with the U.S. Department of Agriculture.
	The Insurance – Overseas General segment comprises ACE International and ACE Global Markets (AGM). ACE International comprises our retail commercial P&C, A&H, and personal lines businesses serving territories outside the U.S., Bermuda, and Canada, and the international supplemental A&H business of Combined Insurance. ACE International maintains a presence in every major insurance market in the world and is organized geographically along product lines that provide dedicated underwriting focus to customers. ACE International has four regions of operations: ACE Europe, ACE Asia Pacific, ACE Far East, and ACE Latin America. During 2013, ACE International expanded its operations with the acquisitions of ABA Seguros and Fianzas Monterrey in Mexico. Refer to Note 2 for additional information. Companies within the Insurance – Overseas General segment write a variety of insurance products including P&C, professional lines (directors and officers and errors and omissions), marine, energy, aviation, political risk, specialty consumer-oriented products, and A&H (principally accident and supplemental health). Combined Insurance distributes a wide range of supplemental A&H products. AGM, our London-based international specialty and excess and surplus lines business, includes Syndicate 2488, a wholly-owned ACE syndicate. AGM offers products through its parallel distribution network via ACE European Group Limited (AEGL) and Syndicate 2488. ACE provides funds at Lloyd's to support underwriting by Syndicate 2488, which is managed by ACE Underwriting Agencies Limited. AGM uses Syndicate 2488 to underwrite P&C business on a global basis through Lloyd's worldwide licenses. AGM uses AEGL to underwrite similar classes of business through its network of U.K. and European licenses, and in the U.S. where it is eligible to write excess and surplus lines business. The reinsurance operation of AGM is included in the Global Reinsurance segment.
	The Global Reinsurance segment represents ACE's reinsurance operations comprising ACE Tempest Re Bermuda, ACE Tempest Re USA, ACE Tempest Re International, and ACE Tempest Re Canada. The Global Reinsurance segment also includes AGM's reinsurance operations. These divisions provide a broad range of traditional and specialty reinsurance products including property catastrophe, casualty, and property reinsurance coverages to a diverse array of primary P&C insurers.
	The Life segment includes ACE's international life operations (ACE Life), ACE Tempest Life Re (ACE Life Re), and the North American supplemental A&H and life business of Combined Insurance. ACE Life provides a broad portfolio of protection and savings products including whole life, endowment plans, individual term life, group term life, group medical, personal accident, credit life, universal life and unit linked contracts through multiple distribution channels primarily in emerging markets including: Egypt, Hong Kong, Indonesia, South Korea, Taiwan, Thailand, and Vietnam; also throughout Latin America, selectively in Europe, and China through a non-consolidated joint venture insurance company. ACE Life Re helps clients (ceding companies) manage mortality, morbidity, and lapse risks embedded in their books of business. ACE Life Re's core business is a Bermuda-based operation which provides reinsurance to primary life insurers, focusing on guarantees included in certain fixed and variable annuity products and also on more traditional mortality reinsurance protection. ACE Life Re's U.S.-based traditional life reinsurance operation was discontinued for new business in January 2010. Since 2007, ACE Life Re has not quoted on new opportunities in the variable annuity reinsurance marketplace. Combined Insurance distributes specialty supplemental A&H and life insurance products targeted to middle income consumers and businesses in the U.S. and Canada.
	Corporate includes ACE Limited, ACE Group Management and Holdings Ltd., ACE INA Holdings, Inc., and intercompany eliminations. Due to our initiatives to reduce reinsurance recoverable balances, losses recognized in connection with the commutation of ceded reinsurance contracts are generally not considered when assessing segment performance and, accordingly, are directly allocated to Corporate. Losses and loss expenses arise in connection with the commutation of ceded reinsurance contracts that result from a differential between the consideration received from reinsurers and the related reduction of reinsurance recoverable, principally related to the time value of money.
	For segment reporting purposes, certain items have been presented in a different manner below than in the consolidated financial statements. Management uses underwriting income as the main measure of segment performance. ACE calculates underwriting income by subtracting Losses and loss expenses, Policy benefits, Policy acquisition costs, and Administrative expenses from Net premiums earned. For the Insurance – North American Agriculture segment, management includes gains and losses from fair value changes on crop derivatives as a component of underwriting income. For 2013, underwriting income in our Insurance – North American Agriculture segment was $89 million. This amount includes $1 million of realized losses related to crop derivatives which are included in Net realized gains (losses) below. For the Life segment, management includes Net investment income and (Gains) losses from fair value changes in separate account assets that do not qualify for separate account reporting under GAAP as components of Life underwriting income. For example, for 2013, Life underwriting income of $374 million includes Net investment income of $251 million and gains from fair value changes in separate account assets of $16 million.
	The following tables present the Statement of Operations by segment:
	For the Year Ended December 31, 2013 (in millions of U.S. dollars)	Insurance –			Insurance – North American Agriculture				Insurance –				Global			Life			Corporate			ACE
		North							Overseas				Reinsurance									Consolidated
		American P&C							General
	Net premiums written	$	5,915		$	1,627			$	6,520			$	991		$	1,972		$	—		$	17,025
	Net premiums earned	5,721			1,678				6,333				976			1,905			—			16,613
	Losses and loss expenses	3,776			1,524				3,062				396			582			8			9,348
	Policy benefits	—			—				—				—			515			—			515
	Policy acquisition costs	597			53				1,453				197			358			1			2,659
	Administrative expenses	601			11				1,008				50			343			198			2,211
	Underwriting income (loss)	747			90				810				333			107			(207		)	1,880
	Net investment income	1,021			26				539				280			251			27			2,144
	Net realized gains (losses) including OTTI	72			1				18				53			360			—			504
	Interest expense	5			1				5				5			15			244			275
	Other (income) expense:
	(Gains) losses from fair value changes in separate account assets	—			—				—				—			(16		)	—			(16		)
	Other	(58		)	32				39				(19		)	13			24			31
	Income tax expense (benefit)	347			20				222				36			34			(179		)	480
	Net income (loss)	$	1,546		$	64			$	1,101			$	644		$	672		$	(269	)	$	3,758
	For the Year Ended December 31, 2012	Insurance –			Insurance – North American Agriculture				Insurance –				Global			Life			Corporate			ACE
	(in millions of U.S. dollars)	North							Overseas				Reinsurance									Consolidated
		American P&C							General
	Net premiums written	$	5,349		$	1,859			$	5,863			$	1,025		$	1,979		$	—		$	16,075
	Net premiums earned	5,147			1,872				5,740				1,002			1,916			—			15,677
	Losses and loss expenses	3,715			1,911				2,862				553			611			1			9,653
	Policy benefits	—			—				—				—			521			—			521
	Policy acquisition costs	558			28				1,353				172			334			1			2,446
	Administrative expenses	608			(7		)		935				51			328			181			2,096
	Underwriting income (loss)	266			(60		)		590				226			122			(183		)	961
	Net investment income	1,066			25				521				290			251			28			2,181
	Net realized gains (losses) including OTTI	41			1				103				6			(72		)	(1		)	78
	Interest expense	12			—				5				4			12			217			250
	Other (income) expense:
	(Gains) losses from fair value changes in separate account assets	—			—				—				—			(29		)	—			(29		)
	Other	(41		)	32				3				(15		)	25			19			23
	Income tax expense (benefit)	229			(29		)		133				15			58			(136		)	270
	Net income (loss)	$	1,173		$	(37	)		$	1,073			$	518		$	235		$	(256	)	$	2,706
	For the Year Ended December 31, 2011	Insurance –			Insurance – North American Agriculture				Insurance –				Global			Life			Corporate			ACE
	(in millions of U.S. dollars)	North							Overseas				Reinsurance									Consolidated
		American P&C							General
	Net premiums written	$	4,900		$	1,951			$	5,629			$	979		$	1,913		$	—		$	15,372
	Net premiums earned	4,969			1,942				5,614				1,003			1,859			—			15,387
	Losses and loss expenses	3,577			1,699				3,029				621			593			1			9,520
	Policy benefits	—			—				—				—			401			—			401
	Policy acquisition costs	532			80				1,335				185			339			1			2,472
	Administrative expenses	598			(6		)		939				52			317			168			2,068
	Underwriting income (loss)	262			169				311				145			209			(170		)	926
	Net investment income	1,148			22				546				287			226			13			2,242
	Net realized gains (losses) including OTTI	28			6				33				(50		)	(806		)	(6		)	(795		)
	Interest expense	13			2				5				2			11			217			250
	Other (income) expense:
(Gains) losses from fair value changes in separate account assets	—			—				—				—			36			—			36
Other	(13		)	18				—				(1		)	26			15			45
Income tax expense (benefit)	344			51				164				30			50			-137			502
Net income (loss)	$	1,094		$	126			$	721			$	351		$	(494	)	$	(258	)	$	1,540
Underwriting assets are reviewed in total by management for purposes of decision-making. Other than goodwill and other intangible assets, ACE does not allocate assets to its segments.
The following table presents net premiums earned for each segment by product:
(in millions of U.S. dollars)	Property &			Casualty				Life,				ACE
	All Other							Accident &				Consolidated
For the Year Ended December 31, 2013								Health
Insurance – North American P&C	$	1,489		$	3,847			$	385			$	5,721
Insurance – North American Agriculture	1,678			—				—				1,678
Insurance – Overseas General	2,672			1,479				2,182				6,333
Global Reinsurance	543			433				—				976
Life	—			—				1,905				1,905
	$	6,382		$	5,759			$	4,472			$	16,613
For the Year Ended December 31, 2012
Insurance – North American P&C	$	1,370		$	3,406			$	371			$	5,147
Insurance – North American Agriculture	1,872			—				—				1,872
Insurance – Overseas General	2,236			1,379				2,125				5,740
Global Reinsurance	495			507				—				1,002
Life	—			—				1,916				1,916
	$	5,973		$	5,292			$	4,412			$	15,677
For the Year Ended December 31, 2011
Insurance – North American P&C	$	1,232		$	3,380			$	357			$	4,969
Insurance – North American Agriculture	1,942			—				—				1,942
Insurance – Overseas General	2,080			1,415				2,119				5,614
Global Reinsurance	458			545				—				1,003
Life	—			—				1,859				1,859
	$	5,712		$	5,340			$	4,335			$	15,387
The following table presents net premiums earned by geographic region. Allocations have been made on the basis of location of risk:
		North America					Asia			Latin America
Years Ended				Europe			Pacific/Far East
2013		58	%	17	%		16	%		9	%
2012		60	%	17	%		16	%		7	%
2011		61	%	18	%		14	%		7	%

Earnings_per_share

Earnings per share	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Earnings per share	'
	Earnings per share
		Years Ended December 31
	(in millions of U.S. dollars, except share and per share data)	2013		2012		2011
	Numerator:
	Net income	$	3,758	$	2,706	$	1,540
	Denominator:
	Denominator for basic earnings per share:
	Weighted-average shares outstanding	340,906,490		339,843,438		338,159,409
	Denominator for diluted earnings per share:
	Share-based compensation plans	3,241,085		2,903,512		2,620,815
	Weighted-average shares outstanding	344,147,575		342,746,950		340,780,224
	and assumed conversions
	Basic earnings per share	$	11.02	$	7.96	$	4.55
	Diluted earnings per share	$	10.92	$	7.89	$	4.52
	Potential anti-dilutive share conversions	1,031,297		896,591		111,326
	Excluded from weighted-average shares outstanding and assumed conversions is the impact of securities that would have been anti-dilutive during the respective years.

Related_party_transaction

Related party transaction	12 Months Ended
	Dec. 31, 2013
Related Party Transactions [Abstract]	'
Related party transactions	'
	Related party transactions
	The ACE Foundation – Bermuda is an unconsolidated not-for-profit organization whose primary purpose is to fund charitable causes in Bermuda. The Trustees are principally ACE management. ACE maintains a non-interest bearing demand note receivable from the ACE Foundation – Bermuda (Borrower), the balance of which was $26 million and $27 million, at December 31, 2013 and 2012, respectively. The receivable is included in Other assets in the consolidated balance sheets. The Borrower has used the related proceeds to finance investments in Bermuda real estate, some of which have been rented to ACE employees at rates established by independent, professional real estate appraisers. The Borrower uses income from the investments to both repay the note and to fund charitable activities. Accordingly, we report the demand note at the lower of its principal value or the fair value of assets held by the Borrower to repay the loan, including the real estate properties.

Statutory_Financial_Informatio

Statutory Financial Information	12 Months Ended
	Dec. 31, 2013
Statutory Financial Information [Abstract]	'
Statutory financial information	'
	Statutory financial information
	Our subsidiaries file financial statements prepared in accordance with statutory accounting practices prescribed or permitted by insurance regulators. Statutory accounting differs from GAAP in the reporting of certain reinsurance contracts, investments, subsidiaries, acquisition expenses, fixed assets, deferred income taxes, and certain other items. Some jurisdictions impose complex regulatory requirements on insurance companies while other jurisdictions impose fewer requirements. In some jurisdictions, we must obtain licenses issued by governmental authorities to conduct local insurance business. These licenses may be subject to reserves and minimum capital and solvency tests. Jurisdictions may impose fines, censure, and/or criminal sanctions for violation of regulatory requirements. The 2013 amounts below are based on estimates.
	ACE's insurance and reinsurance subsidiaries are subject to insurance laws and regulations in the jurisdictions in which they operate. These regulations include restrictions that limit the amount of dividends or other distributions, such as loans or cash advances, available to shareholders without prior approval of the local insurance regulatory authorities. The amount of dividends available to be paid in 2014 without prior approval totals $3.8 billion.
	The statutory capital and surplus of our insurance subsidiaries met regulatory requirements for 2013, 2012, and 2011. The minimum amounts of statutory capital and surplus necessary to satisfy regulatory requirements were $14.5 billion and $14.3 billion for December 31, 2013 and 2012, respectively.
	The combined statutory capital and surplus was $25.6 billion and $24.4 billion at December 31, 2013 and 2012, respectively. The combined statutory net income was $3.7 billion, $2.9 billion, and $1.9 billion for the years ended December 31, 2013, 2012, and 2011, respectively.
	Several insurance subsidiaries follow accounting practices prescribed or permitted by the jurisdiction of domicile that differ from the applicable local statutory practice. The application of prescribed or permitted accounting practices does not have a material impact on ACE's statutory surplus and income. As prescribed by the Restructuring discussed previously in Note 7, certain of our U.S. subsidiaries discount certain A&E liabilities, which increased statutory capital and surplus by approximately $158 million and $161 million at December 31, 2013 and 2012, respectively.

Information_provided_in_connec

Information provided in connection with outstanding debt of subsidiaries	12 Months Ended
	Dec. 31, 2013
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Abstract]	'
Information provided in connection with outstanding debt of subsidiaries	'
	Information provided in connection with outstanding debt of subsidiaries
	The following tables present condensed consolidating financial information at December 31, 2013 and December 31, 2012, and for the years ended December 31, 2013, 2012, and 2011 for ACE Limited (Parent Guarantor) and ACE INA Holdings, Inc. (Subsidiary Issuer). The Subsidiary Issuer is an indirect 100 percent-owned subsidiary of the Parent Guarantor. The Parent Guarantor fully and unconditionally guarantees certain of the debt of the Subsidiary Issuer.
	During the third quarter of 2013, we determined that the Subsidiary Issuer columns presented in the previously issued condensed consolidating financial information should be presented on the equity method of accounting rather than on a consolidated basis. Accordingly, we have revised the disclosure to correct the Condensed Consolidating Balance Sheet as of December 31, 2012, the Condensed Consolidating Statements of Operations and Comprehensive Income for the years ended December 31, 2012 and 2011, and the Condensed Consolidating Statements of Cash Flows for the years ended December 31, 2012 and 2011. As a result of this revision to the Subsidiary Issuer condensed consolidating financial information, the assets and liabilities, revenues and expenses, and cash flows of the subsidiaries of ACE INA Holdings, Inc. (Subsidiary Issuer) are now presented in the Other ACE Limited Subsidiaries column on a combined basis. In addition, we revised the Consolidating Adjustments and Eliminations column to correctly include all intercompany eliminations. Previously, this column reflected only ACE Limited parent company intercompany eliminations. We also revised the Condensed Consolidating Balance Sheet as of December 31, 2012 and Condensed Consolidating Statement of Cash Flows for the years ended December 31, 2012 and 2011 to correct the presentation of negative cash associated with our affiliated notional cash pooling programs (Pools). In addition, certain items in the Condensed Consolidating Statement of Cash Flows for the years ended December 31, 2012 and 2011 have been reclassified to conform to current period presentation. Also, the operating cash flows have been corrected to properly reflect certain intercompany transactions previously recorded in investing and financing cash flows for the years ended December 31, 2012 and 2011.
	Total shareholders' equity and net income of the Subsidiary Issuer and Parent Guarantor were not impacted as a result of these revisions. The impact of the revisions was not material to the prior period consolidated financial statements taken as a whole. There was no impact on the consolidated amounts previously reported. The prior period condensed consolidating financial statements will be similarly revised as the information is presented in the first and second quarter Form 10-Q filings for 2014.
	Condensed Consolidating Balance Sheet at December 31, 2013
	(in millions of U.S. dollars)	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
		(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		Guarantor)			(Subsidiary			Subsidiaries
					Issuer)
	Assets
	Investments	$	32		$	10		$	60,886		$	—		$	60,928
	Cash(1)	—			16			748			(185		)	579
	Insurance and reinsurance balances receivable	—			—			5,835			(809		)	5,026
	Reinsurance recoverable on losses and loss expenses	—			—			20,057			(8,830		)	11,227
	Reinsurance recoverable on policy benefits	—			—			1,215			(997		)	218
	Value of business acquired	—			—			536			—			536
	Goodwill and other intangible assets	—			—			5,404			—			5,404
	Investments in subsidiaries	28,351			18,105			—			(46,456		)	—
	Due from subsidiaries and affiliates, net	844			—			—			(844		)	—
	Other assets	5			258			13,788			(3,459		)	10,592
	Total assets	$	29,232		$	18,389		$	108,469		$	(61,580	)	$	94,510
	Liabilities
	Unpaid losses and loss expenses	$	—		$	—		$	45,714		$	(8,271	)	$	37,443
	Unearned premiums	—			—			9,242			(1,703		)	7,539
	Future policy benefits	—			—			5,612			(997		)	4,615
	Due to (from) subsidiaries and affiliates, net	—			714			130			(844		)	—
	Affiliated notional cash pooling programs(1)	185			—			—			(185		)	—
	Short-term debt	—			500			1,401			—			1,901
	Long-term debt	—			3,795			12			—			3,807
	Trust preferred securities	—			309			—			—			309
	Other liabilities	222			1,318			11,655			(3,124		)	10,071
	Total liabilities	407			6,636			73,766			(15,124		)	65,685
	Total shareholders’ equity	28,825			11,753			34,703			(46,456		)	28,825
	Total liabilities and shareholders’ equity	$	29,232		$	18,389		$	108,469		$	(61,580	)	$	94,510
	(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Refer to Note 1f) for additional information. At December 31, 2013, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
	Condensed Consolidating Balance Sheet at December 31, 2012 (Revised)
	(in millions of U.S. dollars)	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
		(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		Guarantor)			(Subsidiary			Subsidiaries
					Issuer)
	Assets
	Investments	$	31		$	14		$	60,219		$	—		$	60,264
	Cash(1)	103			2			859			(349		)	615
	Insurance and reinsurance balances receivable	—			—			4,742			(595		)	4,147
	Reinsurance recoverable on losses and loss expenses	—			—			20,935			(8,857		)	12,078
	Reinsurance recoverable on policy benefits	—			—			1,229			(988		)	241
	Value of business acquired	—			—			614			—			614
	Goodwill and other intangible assets	—			—			4,975			—			4,975
	Investments in subsidiaries	27,251			17,016			—			(44,267		)	—
	Due from subsidiaries and affiliates, net	204			—			—			(204		)	—
	Other assets	13			210			11,304			(1,916		)	9,611
	Total assets	$	27,602		$	17,242		$	104,877		$	(57,176	)	$	92,545
	Liabilities
	Unpaid losses and loss expenses	$	—		$	—		$	46,109		$	(8,163	)	$	37,946
	Unearned premiums	—			—			8,248			(1,384		)	6,864
	Future policy benefits	—			—			5,458			(988		)	4,470
	Due to subsidiaries and affiliates, net	—			68			136			(204		)	—
	Affiliated notional cash pooling programs(1)	—			349			—			(349		)	—
	Short-term debt	—			—			1,401			—			1,401
	Long-term debt	—			3,347			13			—			3,360
	Trust preferred securities	—			309			—			—			309
	Other liabilities	71			1,195			11,219			(1,821		)	10,664
	Total liabilities	71			5,268			72,584			(12,909		)	65,014
Total shareholders’ equity	27,531			11,974			32,293			(44,267		)	27,531
Total liabilities and shareholders’ equity	$	27,602		$	17,242		$	104,877		$	(57,176	)	$	92,545
(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Refer to Note 1f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condensed Consolidating Balance Sheet at December 31, 2012 (As previously reported)
(in millions of U.S. dollars)	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments(2)			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries and
				Issuer)			Eliminations(1)
Assets
Investments	$	31		$	31,074		$	29,159		$	—		$	60,264
Cash(3)	103			515			(3		)	—			615
Insurance and reinsurance balances receivable	—			3,654			493			—			4,147
Reinsurance recoverable on losses and loss expenses	—			17,232			(5,154		)	—			12,078
Reinsurance recoverable on policy benefits	—			1,187			(946		)	—			241
Value of business acquired	—			610			4			—			614
Goodwill and other intangible assets	—			4,419			556			—			4,975
Investments in subsidiaries	27,251			—			—			(27,251		)	—
Due from subsidiaries and affiliates, net	204			—			—			(204		)	—
Other assets	13			7,563			2,035			—			9,611
Total assets	$	27,602		$	66,254		$	26,144		$	(27,455	)	$	92,545
Liabilities
Unpaid losses and loss expenses	$	—		$	31,356		$	6,590		$	—		$	37,946
Unearned premiums	—			5,872			992			—			6,864
Future policy benefits	—			3,876			594			—			4,470
Due to (from) subsidiaries and affiliates, net	—			384			(180		)	(204		)	—
Short-term debt	—			851			550			—			1,401
Long-term debt	—			3,360			—			—			3,360
Trust preferred securities	—			309			—			—			309
Other liabilities	71			8,272			2,321			—			10,664
Total liabilities	71			54,280			10,867			(204		)	65,014
Total shareholders’ equity	27,531			11,974			15,277			(27,251		)	27,531
Total liabilities and shareholders’ equity	$	27,602		$	66,254		$	26,144		$	(27,455	)	$	92,545
-1	Includes all other subsidiaries of ACE Limited and intercompany eliminations.
-2	Includes ACE Limited parent company eliminations.
-3	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Refer to Note 1f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condensed Consolidating Statements of Operations and Comprehensive Income
For the Year Ended December 31, 2013	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries
(in millions of U.S. dollars)				Issuer)
Net premiums written	$	—		$	—		$	17,025		$	—		$	17,025
Net premiums earned	—			—			16,613			—			16,613
Net investment income	2			3			2,139			—			2,144
Equity in earnings of subsidiaries	3,580			942			—			(4,522		)	—
Net realized gains (losses) including OTTI	—			(2		)	506			—			504
Losses and loss expenses	—			—			9,348			—			9,348
Policy benefits	—			—			515			—			515
Policy acquisition costs and administrative expenses	60			19			4,791			—			4,870
Interest (income) expense	(32		)	270			37			—			275
Other (income) expense	(221		)	27			209			—			15
Income tax expense (benefit)	17			(108		)	571			—			480
Net income	$	3,758		$	735		$	3,787		$	(4,522	)	$	3,758
Comprehensive income	$	2,023		$	(230	)	$	2,051		$	(1,821	)	$	2,023
Condensed Consolidating Statements of Operations and Comprehensive Income (Revised)
For the Year Ended December 31, 2012	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries
(in millions of U.S. dollars)				Issuer)
Net premiums written	$	—		$	—		$	16,075		$	—		$	16,075
Net premiums earned	—			—			15,677			—			15,677
Net investment income	1			3			2,177			—			2,181
Equity in earnings of subsidiaries	2,590			911			—			(3,501		)	—
Net realized gains (losses) including OTTI	17			—			61			—			78
Losses and loss expenses	—			—			9,653			—			9,653
Policy benefits	—			—			521			—			521
Policy acquisition costs and administrative expenses	62			28			4,452			—			4,542
Interest (income) expense	(33		)	235			48			—			250
Other (income) expense	(137		)	9			122			—			(6		)
Income tax expense (benefit)	10			(110		)	370			—			270
Net income	$	2,706		$	752		$	2,749		$	(3,501	)	$	2,706
Comprehensive income	$	3,682		$	1,209		$	3,724		$	(4,933	)	$	3,682
Condensed Consolidating Statements of Operations and Comprehensive Income (As previously reported)
For the Year Ended December 31, 2012	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments (2)			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries and
(in millions of U.S. dollars)				Issuer)			Eliminations(1)
Net premiums written	$	—		$	9,466		$	6,609		$	—		$	16,075
Net premiums earned	—			9,194			6,483			—			15,677
Net investment income	1			1,048			1,132			—			2,181
Equity in earnings of subsidiaries	2,590			—			—			(2,590		)	—
Net realized gains (losses) including OTTI	17			121			(60		)	—			78
Losses and loss expenses	—			6,211			3,442			—			9,653
Policy benefits	—			309			212			—			521
Policy acquisition costs and administrative expenses	62			2,564			1,916			—			4,542
Interest (income) expense	(33		)	257			26			—			250
Other (income) expense	(137		)	77			54			—			(6		)
Income tax expense	10			193			67			—			270
Net income	$	2,706		$	752		$	1,838		$	(2,590	)	$	2,706
Comprehensive income	$	3,682		$	1,209		$	1,381		$	(2,590	)	$	3,682
-1	Includes all other subsidiaries of ACE Limited and intercompany eliminations.
-2	Includes ACE Limited parent company eliminations.
Condensed Consolidating Statements of Operations and Comprehensive Income (Revised)
For the Year Ended December 31, 2011	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries
(in millions of U.S. dollars)				Issuer)
Net premiums written	$	—		$	—		$	15,372		$	—		$	15,372
Net premiums earned	—			—			15,387			—			15,387
Net investment income	2			2			2,238			—			2,242
Equity in earnings of subsidiaries	1,459			989			—			(2,448		)	—
Net realized gains (losses) including OTTI	(4		)	—			(791		)	—			(795		)
Losses and loss expenses	—			—			9,520			—			9,520
Policy benefits	—			—			401			—			401
Policy acquisition costs and administrative expenses	69			37			4,434			—			4,540
Interest (income) expense	(37		)	266			21			—			250
Other (income) expense	(125		)	21			185			—			81
Income tax expense (benefit)	10			(103		)	595			—			502
Net income	$	1,540		$	770		$	1,678		$	(2,448	)	$	1,540
Comprehensive income	$	1,857		$	1,077		$	1,994		$	(3,071	)	$	1,857
Condensed Consolidating Statements of Operations and Comprehensive Income (As previously reported)
For the Year Ended December 31, 2011	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments (2)			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries and
(in millions of U.S. dollars)				Issuer)			Eliminations(1)
Net premiums written	$	—		$	9,081		$	6,291		$	—		$	15,372
Net premiums earned	—			9,082			6,305			—			15,387
Net investment income	2			1,096			1,144			—			2,242
Equity in earnings of subsidiaries	1,459			—			—			(1,459		)	—
Net realized gains (losses) including OTTI	(4		)	62			(853		)	—			(795		)
Losses and loss expenses	—			5,889			3,631			—			9,520
Policy benefits	—			192			209			—			401
Policy acquisition costs and administrative expenses	69			2,561			1,910			—			4,540
Interest (income) expense	(37		)	267			20			—			250
Other (income) expense	(125		)	143			63			—			81
Income tax expense	10			418			74			—			502
Net income	$	1,540		$	770		$	689		$	(1,459	)	$	1,540
Comprehensive income	$	1,857		$	1,077		$	382		$	(1,459	)	$	1,857
(1)	Includes all other subsidiaries of ACE Limited and intercompany eliminations.
(2)	Includes ACE Limited parent company eliminations.
Condensed Consolidating Statement of Cash Flows
For the Year Ended December 31, 2013	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries
(in millions of U.S. dollars)				Issuer)
Net cash flows from (used for) operating activities	$	970		$	(107	)	$	3,984		$	(825	)	$	4,022
Cash flows from investing activities
Purchases of fixed maturities available for sale	—			—			(21,504		)	106			(21,398		)
Purchases of fixed maturities held to maturity	—			—			(447		)	—			(447		)
Purchases of equity securities	—			—			(264		)	—			(264		)
Sales of fixed maturities available for sale	—			—			10,519			(106		)	10,413
Sales of equity securities	—			—			142			—			142
Maturities and redemptions of fixed maturities available for sale	—			—			6,941			—			6,941
Maturities and redemptions of fixed maturities held to maturity	—			—			1,488			—			1,488
Net change in short-term investments	(1		)	4			521			—			524
Net derivative instruments settlements	—			(1		)	(470		)	—			(471		)
Acquisition of subsidiaries (net of cash acquired of $38)	—			—			(977		)	—			(977		)
Capital contribution	(133		)	(1,097		)	—			1,230			—
Other	—			(4		)	(389		)	—			(393		)
Net cash flows used for investing activities	(134		)	(1,098		)	(4,440		)	1,230			(4,442		)
Cash flows from financing activities
Dividends paid on Common Shares	(517		)	—			—			—			(517		)
Common Shares repurchased	—			—			(287		)	—			(287		)
Net proceeds from issuance of long-term debt	—			947			—			—			947
Proceeds from share-based compensation plans, including windfall tax benefits	14			—			121			—			135
Advances (to) from affiliates	(621		)	621			—			—			—
Dividends to parent company	—			—			(825		)	825			—
Capital contribution	—			—			1,230			(1,230		)	—
Net proceeds from (payments to) affiliated notional cash pooling programs(1)	185			(349		)	—			164			—
Other	—			—			113			—			113
Net cash flows (used for) from financing activities	(939		)	1,219			352			(241		)	391
Effect of foreign currency rate changes on cash and cash equivalents	—			—			(7		)	—			(7		)
Net (decrease) increase in cash	(103		)	14			(111		)	164			(36		)
Cash – beginning of year(1)	103			2			859			(349		)	615
Cash – end of year(1)	$	—		$	16		$	748		$	(185	)	$	579
(1)	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2013 and December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condensed Consolidating Statement of Cash Flows (Revised)
For the Year Ended December 31, 2012	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries
(in millions of U.S. dollars)				Issuer)
Net cash flows from operating activities	$	573		$	296		$	3,876		$	(750	)	$	3,995
Cash flows from investing activities
Purchases of fixed maturities available for sale	—			—			(24,076		)	115			(23,961		)
Purchases of fixed maturities held to maturity	—			—			(388		)	—			(388		)
Purchases of equity securities	—			—			(135		)	—			(135		)
Sales of fixed maturities available for sale	—			—			14,884			(115		)	14,769
Sales of equity securities	—			—			119			—			119
Maturities and redemptions of fixed maturities available for sale	—			—			5,523			—			5,523
Maturities and redemptions of fixed maturities held to maturity	—			—			1,451			—			1,451
Net change in short-term investments	—			(4		)	121			—			117
Net derivative instruments settlements	(1		)	—			(280		)	—			(281		)
Capital contribution	—			(352		)	(90		)	442			—
Acquisition of subsidiaries (net of cash acquired of $8)	—			—			(98		)	—			(98		)
Other	—			(33		)	(522		)	—			(555		)
Net cash flows used for investing activities	(1		)	(389		)	(3,491		)	442			(3,439		)
Cash flows from financing activities
Dividends paid on Common Shares	(815		)	—			—			—			(815		)
Common Shares repurchased	—			—			(11		)	—			(11		)
Net proceeds from issuance of short-term debt	—			—			150			—			150
Proceeds from share-based compensation plans, including windfall tax benefits	34			—			92			—			126
Advances from (to) affiliates	206			(201		)	(5		)	—			—
Dividends to parent company	—			—			(750		)	750			—
Capital contribution	—			90			352			(442		)	—
Net proceeds from affiliated notional cash pooling programs(1)	—			201			—			(201		)	—
Net cash flows (used for) from financing activities	(575		)	90			(172		)	107			(550		)
Effect of foreign currency rate changes on cash and cash equivalents	—			—			(5		)	—			(5		)
Net increase (decrease) in cash	(3		)	(3		)	208			(201		)	1
Cash – beginning of year(1)	106			5			651			(148		)	614
Cash – end of year(1)	$	103		$	2		$	859		$	(349	)	$	615
-1	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2012 and December 31, 2011, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condensed Consolidating Statement of Cash Flows (As previously reported)
For the Year Ended December 31, 2012	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments (2)			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries and
(in millions of U.S. dollars)				Issuer)			Eliminations(1)
Net cash flows from operating activities	$	781		$	1,744		$	1,920		$	(450	)	$	3,995
Cash flows from investing activities
Purchases of fixed maturities available for sale	—			(11,843		)	(12,001		)	—			(23,844		)
Purchases of fixed maturities held to maturity	—			(384		)	(4		)	—			(388		)
Purchases of equity securities	—			(70		)	(65		)	—			(135		)
Sales of fixed maturities available for sale	—			7,347			7,422			—			14,769
Sales of equity securities	—			59			60			—			119
Maturities and redemptions of fixed maturities available for sale	—			2,759			2,764			—			5,523
Maturities and redemptions of fixed maturities held to maturity	—			1,045			406			—			1,451
Net derivative instruments settlements	(1		)	(6		)	(274		)	—			(281		)
Capital contribution	—			—			(90		)	90			—
Advances from (to) affiliates	(2		)	—			—			2			—
Acquisition of subsidiaries (net of cash acquired of $8)	—			(111		)	13			—			(98		)
Other	—			(395		)	(160		)	—			(555		)
Net cash flows used for investing activities	(3		)	(1,599		)	(1,929		)	92			(3,439		)
Cash flows from financing activities
Dividends paid on Common Shares	(815		)	—			—			—			(815		)
Common Shares repurchased	—			—			(11		)	—			(11		)
Net proceeds from issuance of short-term debt	—			1			149			—			150
Proceeds from share-based compensation plans, including windfall tax benefits	34			13			79			—			126
Advances (to) from affiliates	—			(105		)	107			(2		)	—
Dividends to parent company	—			—			(450		)	450			—
Capital contribution	—			90			—			(90		)	—
Net cash flows used for financing activities	(781		)	(1		)	(126		)	358			(550		)
Effect of foreign currency rate changes on cash and cash equivalents	—			(11		)	6			—			(5		)
Net increase (decrease) in cash	(3		)	133			(129		)	—			1
Cash – beginning of year	106			382			126			—			614
Cash – end of year(3)	$	103		$	515		$	(3	)	$	—		$	615
(1)	Includes all other subsidiaries of ACE Limited and intercompany eliminations.
(2)	Includes ACE Limited parent company eliminations and certain consolidating adjustments.
(3)	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condensed Consolidating Statement of Cash Flows (Revised)
For the Year Ended December 31, 2011	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries
(in millions of U.S. dollars)				Issuer)
Net cash flows from operating activities	$	831		$	1,221		$	3,455		$	(2,037	)	$	3,470
Cash flows from investing activities
Purchases of fixed maturities available for sale	—			—			(24,601		)	323			(24,278		)
Purchases of fixed maturities held to maturity	—			—			(340		)	—			(340		)
Purchases of equity securities	—			—			(309		)	—			(309		)
Sales of fixed maturities available for sale	—			—			18,294			(323		)	17,971
Sales of equity securities	—			—			376			—			376
Maturities and redemptions of fixed maturities available for sale	—			—			3,720			—			3,720
Maturities and redemptions of fixed maturities held to maturity	—			—			1,279			—			1,279
Net change in short-term investments	9			—			(309		)	—			(300		)
Net derivative instruments settlements	(3		)	—			(64		)	—			(67		)
Capital contribution	(385		)	(581		)	—			966			—
Acquisition of subsidiaries (net of cash acquired of $91)	—			(76		)	(530		)	—			(606		)
Other	—			(19		)	(463		)	—			(482		)
Net cash flows used for investing activities	(379		)	(676		)	(2,947		)	966			(3,036		)
Cash flows from financing activities
Dividends paid on Common Shares	(459		)	—			—			—			(459		)
Common Shares repurchased	—			—			(195		)	—			(195		)
Net proceeds from issuance (repayments) of short-term debt	(300		)	—			250			—			(50		)
Proceeds from share-based compensation plans, including windfall tax benefits	133			—			6			—			139
Advances from (to) affiliates	(28		)	(721		)	749			—			—
Dividends to parent company	—			—			(2,037		)	2,037			—
Capital contribution	—			—			966			(966		)	—
Net proceeds from affiliated notional cash pooling programs(1)	—			148			—			(148		)	—
Net cash flows used for financing activities	(654		)	(573		)	(261		)	923			(565		)
Effect of foreign currency rate changes on cash and cash equivalents	—			—			(27		)	—			(27		)
Net increase (decrease) in cash	(202		)	(28		)	220			(148		)	(158		)
Cash – beginning of year(1)	308			33			431			—			772
Cash – end of year(1)	$	106		$	5		$	651		$	(148	)	$	614
-1	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2011 and December 31, 2010, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condensed Consolidating Statement of Cash Flows (As previously reported)
For the Year Ended December 31, 2011	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments (2)			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries and
(in millions of U.S. dollars)				Issuer)			Eliminations(1)
Net cash flows from operating activities	$	762		$	1,053		$	2,395		$	(740	)	$	3,470
Cash flows from investing activities
Purchases of fixed maturities available for sale	—			(12,203		)	(12,375		)	—			(24,578		)
Purchases of fixed maturities held to maturity	—			(338		)	(2		)	—			(340		)
Purchases of equity securities	—			(157		)	(152		)	—			(309		)
Sales of fixed maturities available for sale	9			9,718			8,244			—			17,971
Sales of equity securities	—			354			22			—			376
Maturities and redemptions of fixed maturities available for sale	—			1,784			1,936			—			3,720
Maturities and redemptions of fixed maturities held to maturity	—			933			346			—			1,279
Net derivative instruments settlements	(3		)	(24		)	(40		)	—			(67		)
Capital contribution	(385		)	—			—			385			—
Advances from (to) affiliates	41			—			—			(41		)	—
Acquisition of subsidiaries (net of cash acquired of $91)	—			(569		)	(37		)	—			(606		)
Other	—			(420		)	(62		)	—			(482		)
Net cash flows used for investing activities	(338		)	(922		)	(2,120		)	344			(3,036		)
Cash flows from financing activities
Dividends paid on Common Shares	(459		)	—			—			—			(459		)
Common Shares repurchased	—			—			(195		)	—			(195		)
Net proceeds from (repayments) issuance of short-term debt	(300		)	(150		)	400			—			(50		)
Net proceeds from share-based compensation plans, including windfall tax benefits	133			3			3			—			139
Advances from (to) affiliates	—			(149		)	108			41			—
Dividends to parent company	—			—			(740		)	740			—
Capital contribution	—			—			385			(385		)	—
Net cash flows used for financing activities	(626		)	(296		)	(39		)	396			(565		)
Effect of foreign currency rate changes on cash and cash equivalents	—			(26		)	(1		)	—			(27		)
Net increase (decrease) in cash	(202		)	(191		)	235			—			(158		)
Cash – beginning of year(3)	308			573			(109		)	—			772
Cash – end of year	$	106		$	382		$	126		$	—		$	614
-1	Includes all other subsidiaries of ACE Limited and intercompany eliminations.
-2	Includes ACE Limited parent company eliminations and certain consolidating adjustments.
-3	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2010, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

Condensed_Unaudited_Quarterly_

Condensed Unaudited Quarterly Financial Data	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Condensed unaudited quarterly financial data	'
	Condensed unaudited quarterly financial data
		Three Months Ended
		31-Mar		30-Jun			30-Sep			31-Dec
	(in millions of U.S. dollars, except per share data)	2013		2013			2013			2013
	Net premiums earned	$	3,573	$	4,067		$	4,610		$	4,363
	Net investment income	531		534			522			557
	Net realized gains (losses) including OTTI	206		104			40			154		(1)
	Total revenues	$	4,310	$	4,705		$	5,172		$	5,074
	Losses and loss expenses	$	1,926	$	2,250		$	2,655		$	2,517
	Policy benefits	$	131	$	110		$	138		$	136
	Net income	$	953	$	891		$	916		$	998
	Basic earnings per share	$	2.8	$	2.61		$	2.68		$	2.93
	Diluted earnings per share	$	2.77	$	2.59		$	2.66		$	2.9
	(1)	Includes a realized gain of $92 million for an out-of-period adjustment related to guaranteed living benefits. Refer to Note 4 a) for additional information.
		Three Months Ended
		31-Mar		30-Jun			30-Sep			31-Dec
	(in millions of U.S. dollars, except per share data)	2012		2012			2012			2012
	Net premiums earned	$	3,381	$	3,783		$	4,665		$	3,848
	Net investment income	544		537			533			567
	Net realized gains (losses) including OTTI	260		(394		)	(60		)	272
	Total revenues	$	4,185	$	3,926		$	5,138		$	4,687
	Losses and loss expenses	$	1,804	$	2,119		$	3,047		$	2,683
	Policy benefits	$	147	$	102		$	130		$	142
	Net income	$	973	$	328		$	640		$	765
	Basic earnings per share	$	2.87	$	0.96		$	1.88		$	2.24
	Diluted earnings per share	$	2.84	$	0.96		$	1.86		$	2.22

Schedule_I

Schedule I	12 Months Ended
	Dec. 31, 2013
Summary of Investments, Other than Investments in Related Parties [Abstract]	'
Schedule I: SUMMARY OF INVESTEMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES	'
	SUMMARY OF INVESTMENTS – OTHER THAN INVESTMENTS IN RELATED PARTIES
	31-Dec-13	Cost or		Fair Value		Amount at Which Shown in the Balance Sheet
	(in millions of U.S. dollars)	Amortized Cost
	Fixed maturities available for sale
	U.S. Treasury and agency	$	2,946	$	2,949	$	2,949
	Foreign	14,336		14,591		14,591
	Corporate securities	16,825		17,470		17,470
	Mortgage-backed securities	10,937		10,894		10,894
	States, municipalities, and political subdivisions	3,362		3,350		3,350
	Total fixed maturities available for sale	48,406		49,254		49,254
	Fixed maturities held to maturity
	U.S. Treasury and agency	820		832		820
	Foreign	864		897		864
	Corporate securities	1,922		2,005		1,922
	Mortgage-backed securities	1,341		1,379		1,341
	States, municipalities, and political subdivisions	1,151		1,150		1,151
	Total fixed maturities held to maturity	6,098		6,263		6,098
	Equity securities
	Industrial, miscellaneous, and all other	841		837		837
	Short-term investments	1,763		1,763		1,763
	Other investments	2,671		2,976		2,976
		4,434		4,739		4,739
	Total investments - other than investments in related parties	$	59,779	$	61,093	$	60,928

Schedule_II

Schedule II	12 Months Ended
	Dec. 31, 2013
Condensed Financial Information of Parent Company Only Disclosure [Abstract]	'
Schedule II - CONDENSED FINANCIAL INFORMATION OF REGISTRANT	'
	CONDENSED FINANCIAL INFORMATION OF REGISTRANT
	BALANCE SHEETS (Parent Company Only)
		31-Dec				31-Dec
	(in millions of U.S. dollars)	2013				2012
	Assets
	Investments in subsidiaries and affiliates on equity basis	$	28,351			$	27,251
	Short-term investments	2				1
	Other investments, at cost	30				30
	Total investments	28,383				27,282
	Cash	—				103
	Due from subsidiaries and affiliates, net	844				204
	Other assets	5				13
	Total assets	$	29,232			$	27,602
	Liabilities
	Affiliated notional cash pooling programs(1)	$	185			$	—
	Accounts payable, accrued expenses, and other liabilities	222				71
	Total liabilities	407				71
	Shareholders' equity
	Common Shares	8,899				9,591
	Common Shares in treasury	(255		)		(159		)
	Additional paid-in capital	5,238				5,179
	Retained earnings	13,791				10,033
	Accumulated other comprehensive income	1,152				2,887
	Total shareholders' equity	28,825				27,531
	Total liabilities and shareholders' equity	$	29,232			$	27,602
	(1) ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Refer to Note 1f) for additional information. At December 31, 2013, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
	The condensed financial information should be read in conjunction with the consolidated financial statements and notes thereto.
	CONDENSED FINANCIAL INFORMATION OF REGISTRANT
	STATEMENTS OF OPERATIONS (Parent Company Only)
		Years Ended December 31
	(in millions of U.S. dollars)	2013			2012			2011
	Revenues
	Investment income, including interest income	$	34		$	34		$	39
	Equity in net income of subsidiaries and affiliates	3,580			2,590			1,459
	Net realized gains (losses)	—			17			(4		)
		3,614			2,641			1,494
	Expenses
	Administrative and other (income) expense	(161		)	(75		)	(56		)
	Income tax expense	17			10			10
		(144		)	(65		)	(46		)
	Net income	$	3,758		$	2,706		$	1,540
	Comprehensive income	$	2,023		$	3,682		$	1,857
	The condensed financial information should be read in conjunction with the consolidated financial statements and notes thereto.
	CONDENSED FINANCIAL INFORMATION OF REGISTRANT
	STATEMENTS OF CASH FLOWS (Parent Company Only)
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012(1)				2011(1)
	Net cash flows from operating activities(2)	$	970			$	573			$	831
	Cash flows from investing activities
	Net change in short-term investments	(1		)		—				9
	Net derivative instruments settlements	—				(1		)		-3
	Capital contribution	(133		)		—				(385		)
	Net cash flows used for investing activities	(134		)		(1		)		(379		)
	Cash flows from financing activities
	Dividends paid on Common Shares	(517		)		(815		)		(459		)
	Net repayments of short-term debt	—				—				(300		)
	Proceeds from share-based compensation plans	14				34				133
	Advances (to) from affiliates	(621		)		206				(28		)
	Net proceeds from affiliated notional cash pooling programs(3)	185				—				—
	Net cash flows used for financing activities	(939		)		(575		)		(654		)
	Net decrease in cash	(103		)		(3		)		(202		)
	Cash – beginning of year	103				106				308
	Cash – end of year	$	—			$	103			$	106
(1) Certain items in the Condensed Statements of Cash Flows for the years ended December 31, 2012 and 2011 have been revised. Refer to Note 19 to the Consolidated Financial Statements for additional information.
(2) Includes cash dividends received from subsidiaries of $825 million, $450 million, and $740 million in 2013, 2012, and 2011, respectively.
(3) ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Refer to Note 1f) for additional information. At December 31, 2013, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
The condensed financial information should be read in conjunction with the consolidated financial statements and notes thereto.

Schedule_IV

Schedule IV	12 Months Ended
	Dec. 31, 2013
Supplemental Schedule of Reinsurance Premiums for Insurance Companies [Abstract]	'
SUPPLEMENTAL INFORMATION CONCERNING REINSURANCE	'
	SUPPLEMENTAL INFORMATION CONCERNING REINSURANCE
	Premiums Earned
	For the years ended December 31, 2013, 2012, and 2011 (in millions of U.S. dollars, except for percentages)	Direct Amount		Ceded To Other Companies		Assumed From Other Companies		Net Amount		Percentage of Amount Assumed to Net
	2013	$	18,856	$	5,722	$	3,479	$	16,613	21	%
	2012	$	17,802	$	5,427	$	3,302	$	15,677	21	%
	2011	$	17,534	$	5,496	$	3,349	$	15,387	22	%

Schedule_VI

Schedule VI	12 Months Ended
	Dec. 31, 2013
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]	'
SUPPLEMENTARY INFORMATION CONCERNING PROPERTY AND CASUALTY OPERATIONS	'
	SUPPLEMENTARY INFORMATION CONCERNING PROPERTY AND CASUALTY OPERATIONS
	As of and for the years ended December 31, 2013, 2012, and 2011 (in millions of U.S. dollars)
		Deferred Policy Acquisition Costs		Net Reserves for Unpaid Losses and Loss Expenses		Unearned Premiums		Net Premiums Earned		Net Investment Income		Net Losses and Loss Expenses Incurred Related to						Amortization of Deferred Policy Acquisition Costs		Net Paid Losses and Loss Expenses		Net Premiums Written
													Current Year		Prior Year
	2013	$	1,865	$	26,831	$	7,539	$	15,708	$	1,977		$	9,878	$	(530	)	$	2,447	$	8,977	$	16,069
	2012	$	1,757	$	26,547	$	6,864	$	14,764	$	2,018		$	10,132	$	(479	)	$	2,254	$	9,219	$	15,107
	2011	$	1,512	$	25,875	$	6,334	$	14,523	$	2,107		$	10,076	$	(556	)	$	2,291	$	8,866	$	14,455

Summary_of_significant_account1

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of presentation	'
	Basis of presentation
	ACE Limited is a holding company incorporated in Zurich, Switzerland. ACE Limited, through its subsidiaries, provides a broad range of insurance and reinsurance products to insureds worldwide. ACE operates through five business segments: Insurance – North American P&C, Insurance – North American Agriculture, Insurance – Overseas General, Global Reinsurance, and Life. Refer to Note 15 for additional information.
	The accompanying consolidated financial statements, which include the accounts of ACE Limited and its subsidiaries (collectively, ACE, we, us, or our), have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and, in the opinion of management, reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of the results and financial position for such periods. All significant intercompany accounts and transactions have been eliminated.
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Amounts included in the consolidated financial statements reflect our best estimates and assumptions; actual amounts could differ materially from these estimates. ACE's principal estimates include:
	•	unpaid loss and loss expense reserves, including long-tail asbestos and environmental (A&E) reserves;
	•	future policy benefits reserves;
	•	the valuation of value of business acquired (VOBA) and amortization of deferred policy acquisition costs and VOBA;
	•	reinsurance recoverable, including a provision for uncollectible reinsurance;
	•	the assessment of risk transfer for certain structured insurance and reinsurance contracts;
	•	the valuation of the investment portfolio and assessment of OTTI;
	•	the valuation of deferred tax assets;
	•	the valuation of derivative instruments related to guaranteed living benefits (GLB); and
	•	the valuation of goodwill.
Premiums	'
	Premiums
	Premiums are generally recognized as written upon inception of the policy. For multi-year policies for which premiums written are payable in annual installments, only the current annual premium is included as written at policy inception due to the ability of the insured/reinsured to commute or cancel coverage within the policy term. The remaining annual premiums are included as written at each successive anniversary date within the multi-year term.
	For property and casualty (P&C) insurance and reinsurance products, premiums written are primarily earned on a pro-rata basis over the policy terms to which they relate. Unearned premiums represent the portion of premiums written applicable to the unexpired portion of the policies in force. For retrospectively-rated policies, written premiums are adjusted to reflect expected ultimate premiums consistent with changes to reported losses, or other measures of exposure as stated in the policy, and earned over the policy coverage period. For retrospectively-rated multi-year policies, premiums recognized in the current period are computed, using a with-and-without method, as the difference between the ceding enterprise's total contract costs before and after the experience under the contract at the reporting date. Accordingly, for retrospectively-rated multi-year policies, additional premiums are generally written and earned when losses are incurred.
	Mandatory reinstatement premiums assessed on reinsurance policies are earned in the period of the loss event that gave rise to the reinstatement premiums.  All remaining unearned premiums are recognized over the remaining coverage period.
	Premiums from long-duration contracts such as certain traditional term life, whole life, endowment, and long-duration personal accident and health (A&H) policies are generally recognized as revenue when due from policyholders. Traditional life policies include those contracts with fixed and guaranteed premiums and benefits. Benefits and expenses are matched with income to result in the recognition of profit over the life of the contracts.
	Retroactive loss portfolio transfer (LPT) contracts in which the insured loss events occurred prior to contract inception are evaluated to determine whether they meet criteria for reinsurance accounting. If reinsurance accounting is appropriate, written premiums are fully earned and corresponding losses and loss expenses recognized at contract inception. These contracts can cause significant variances in gross premiums written, net premiums written, net premiums earned, and net incurred losses in the years in which they are written. Reinsurance contracts sold not meeting criteria for reinsurance accounting are recorded using the deposit method as described below in Note 1 k).
	Reinsurance premiums assumed are based on information provided by ceding companies supplemented by our own estimates of premium when we have not received ceding company reports. Estimates are reviewed and adjustments are recorded in the period in which they are determined. Premiums are earned over the coverage terms of the related reinsurance contracts and range from one to three years.
Deferred policy acquisition costs and value of business acquired	'
	Deferred policy acquisition costs and value of business acquired
	Policy acquisition costs consist of commissions (direct and ceded), premium taxes, and certain underwriting costs related directly to the successful acquisition of new or renewal insurance contracts. A VOBA intangible asset is established upon the acquisition of blocks of long-duration contracts in a business combination and represents the present value of estimated net cash flows for the contracts in force at the acquisition date. Acquisition costs and VOBA, collectively policy acquisition costs, are deferred and amortized. Amortization is recorded in Policy acquisition costs in the consolidated statements of operations. Policy acquisition costs on P&C contracts are generally amortized ratably over the period in which premiums are earned. Policy acquisition costs on traditional long-duration contracts are amortized over the estimated life of the contracts, generally in proportion to premium revenue recognized. For non-traditional long-duration contracts, we amortize policy acquisition costs over the expected life of the contracts in proportion to expected gross profits.  The effect of changes in estimates of expected gross profits is reflected in the period the estimates are revised. Policy acquisition costs are reviewed to determine if they are recoverable from future income, including investment income. Unrecoverable policy acquisition costs are expensed in the period identified.
	Advertising costs are expensed as incurred except for direct-response campaigns that qualify for cost deferral, principally related to A&H business produced by the Insurance – Overseas General segment, which are deferred and recognized as a component of policy acquisition costs. For individual direct-response marketing campaigns that we can demonstrate have specifically resulted in incremental sales to customers and such sales have probable future economic benefits, incremental costs directly related to the marketing campaigns are capitalized. Deferred marketing costs are reviewed regularly for recoverability from future income, including investment income, and amortized in proportion to premium revenue recognized, primarily over a ten-year period, the expected economic future benefit period. The expected future benefit period is evaluated periodically based on historical results and adjusted prospectively. The amount of deferred marketing costs reported in Deferred policy acquisition costs in the consolidated balance sheets was $307 million and $274 million at December 31, 2013 and 2012, respectively. Amortization expense for deferred marketing costs was $128 million, $119 million, and $128 million for the years ended December 31, 2013, 2012, and 2011, respectively (2012 disclosure amount adjusted to present deferred marketing amortization costs in a manner consistent with the 2013 amount).
Reinsurance	'
	Reinsurance
	ACE assumes and cedes reinsurance with other insurance companies to provide greater diversification of business and minimize the net loss potential arising from large risks. Ceded reinsurance contracts do not relieve ACE of its primary obligation to policyholders.
	For both ceded and assumed reinsurance, risk transfer requirements must be met in order to account for a contract as reinsurance, principally resulting in the recognition of cash flows under the contract as premiums and losses. To meet risk transfer requirements, a reinsurance contract must include insurance risk, consisting of both underwriting and timing risk, and a reasonable possibility of a significant loss for the assuming entity. To assess risk transfer for certain contracts, ACE generally develops expected discounted cash flow analyses at contract inception. Deposit accounting is used for contracts that do not meet risk transfer requirements. Deposit accounting requires that consideration received or paid be recorded in the balance sheet as opposed to recording premiums written or losses incurred in the statement of operations. Non-refundable fees on deposit contracts are earned based on the terms of the contract described below in Note 1 k).
	Reinsurance recoverable includes balances due from reinsurance companies for paid and unpaid losses and loss expenses and policy benefits that will be recovered from reinsurers, based on contracts in force. The method for determining the reinsurance recoverable on unpaid losses and loss expenses incurred but not reported (IBNR) involves actuarial estimates consistent with those used to establish the associated liability for unpaid losses and loss expenses as well as a determination of ACE's ability to cede unpaid losses and loss expenses under the terms of the reinsurance agreement.
	Reinsurance recoverable is presented net of a provision for uncollectible reinsurance determined based upon a review of the financial condition of reinsurers and other factors. The provision for uncollectible reinsurance is based on an estimate of the reinsurance recoverable balance that will ultimately be unrecoverable due to reinsurer insolvency, a contractual dispute, or any other reason. The valuation of this provision includes several judgments including certain aspects of the allocation of reinsurance recoverable on IBNR claims by reinsurer and a default analysis to estimate uncollectible reinsurance. The primary components of the default analysis are reinsurance recoverable balances by reinsurer, net of collateral, and default factors used to determine the portion of a reinsurer's balance deemed uncollectible. The definition of collateral for this purpose requires some judgment and is generally limited to assets held in an ACE-only beneficiary trust, letters of credit, and liabilities held with the same legal entity for which ACE believes there is a contractual right of offset. The determination of the default factor is principally based on the financial strength rating of the reinsurer. Default factors require considerable judgment and are determined using the current financial strength rating, or rating equivalent, of each reinsurer as well as other key considerations and assumptions. The more significant considerations include, but are not necessarily limited to, the following:
	•	For reinsurers that maintain a financial strength rating from a major rating agency, and for which recoverable balances are considered representative of the larger population (i.e., default probabilities are consistent with similarly rated reinsurers and payment durations conform to averages), the financial rating is based on a published source and the default factor is based on published default statistics of a major rating agency applicable to the reinsurer's particular rating class. When a recoverable is expected to be paid in a brief period of time by a highly rated reinsurer, such as certain property catastrophe claims, a default factor may not be applied;
	•	For balances recoverable from reinsurers that are both unrated by a major rating agency and for which management is unable to determine a credible rating equivalent based on a parent, affiliate, or peer company, we determine a rating equivalent based on an analysis of the reinsurer that considers an assessment of the creditworthiness of the particular entity, industry benchmarks, or other factors as considered appropriate. We then apply the applicable default factor for that rating class. For balances recoverable from unrated reinsurers for which the ceded reserve is below a certain threshold, we generally apply a default factor of 34 percent, consistent with published statistics of a major rating agency;
	•	For balances recoverable from reinsurers that are either insolvent or under regulatory supervision, we establish a default factor and resulting provision for uncollectible reinsurance based on reinsurer-specific facts and circumstances. Upon initial notification of an insolvency, we generally recognize an expense for a substantial portion of all balances outstanding, net of collateral, through a combination of write-offs of recoverable balances and increases to the provision for uncollectible reinsurance. When regulatory action is taken on a reinsurer, we generally recognize a default factor by estimating an expected recovery on all balances outstanding, net of collateral. When sufficient credible information becomes available, we adjust the provision for uncollectible reinsurance by establishing a default factor pursuant to information received; and
	•	For other recoverables, management determines the provision for uncollectible reinsurance based on the specific facts and circumstances.
	The methods used to determine the reinsurance recoverable balance and related provision for uncollectible reinsurance are regularly reviewed and updated, and any resulting adjustments are reflected in earnings in the period identified.
	Prepaid reinsurance premiums represent the portion of premiums ceded to reinsurers applicable to the unexpired coverage terms of the reinsurance contracts in force.
	The value of reinsurance business assumed of $27 million and $32 million at December 31, 2013 and 2012, respectively, included in Other assets in the accompanying consolidated balance sheets, represents the excess of estimated ultimate value of the liabilities assumed under retroactive reinsurance contracts over consideration received. The value of reinsurance business assumed is amortized and recorded to losses and loss expenses based on the payment pattern of the losses assumed and ranges between 9 and 40 years. The unamortized value is reviewed regularly to determine if it is recoverable based upon the terms of the contract, estimated losses and loss expenses, and anticipated investment income. Unrecoverable amounts are expensed in the period identified.
Investments	'
	Investments
	Fixed maturities are classified as either available for sale or held to maturity. The available for sale portfolio is reported at fair value. The held to maturity portfolio includes securities for which we have the ability and intent to hold to maturity or redemption and is reported at amortized cost. Equity securities are classified as available for sale and are recorded at fair value. Short-term investments comprise securities due to mature within one year of the date of purchase and are recorded at fair value which typically approximates cost. Short-term investments include certain cash and cash equivalents, which are part of investment portfolios under the management of external investment managers.
	Other investments principally comprise life insurance policies, policy loans, trading securities, other direct equity investments, investment funds, and limited partnerships.
	•	Life insurance policies are carried at policy cash surrender value.
	•	Policy loans are carried at outstanding balance.
	•	Trading securities are recorded on a trade date basis and carried at fair value. Unrealized gains and losses on trading securities are reflected in Net income.
	•	Other investments over which ACE can exercise significant influence are accounted for using the equity method.
	•	All other investments over which ACE cannot exercise significant influence are carried at fair value with changes in fair value recognized through OCI. For these investments, investment income and realized gains are recognized as related distributions are received.
	•	Partially-owned investment companies comprise entities in which we hold an ownership interest in excess of three percent. These investments as well as ACE's investments in investment funds where our ownership interest is in excess of three percent are accounted for under the equity method because ACE exerts significant influence. These investments apply investment company accounting to determine operating results, and ACE retains the investment company accounting in applying the equity method. This means that investment income, realized gains or losses, and unrealized gains or losses are included in the portion of equity earnings reflected in Other (income) expense.
	Investments in partially-owned insurance companies primarily represent direct investments in which ACE has significant influence and, as such, meet the requirements for equity accounting. We report our share of the net income or loss of the partially-owned insurance companies in Other (income) expense. Investments in partially-owned insurance companies over which ACE does not exert significant influence are carried at fair value with changes in fair value recognized through OCI.
	Realized gains or losses on sales of investments are determined on a first-in, first-out basis. Unrealized appreciation (depreciation) on investments is included as a separate component of AOCI in Shareholders' equity. We regularly review our investments for OTTI. Refer to Note 3 for additional information.
	With respect to securities where the decline in value is determined to be temporary and the security's value is not written down, a subsequent decision may be made to sell that security and realize a loss. Subsequent decisions on security sales are the result of changing or unforeseen facts and circumstances (i.e., arising from a large insured loss such as a catastrophe), deterioration of the creditworthiness of the issuer or its industry, or changes in regulatory requirements. We believe that subsequent decisions to sell such securities are consistent with the classification of the majority of the portfolio as available for sale.
	We use derivative instruments including futures, options, swaps, and foreign currency forward contracts for the purpose of managing certain investment portfolio risks and exposures. Refer to Note 10 for additional information. Derivatives are reported at fair value and are recorded in the accompanying consolidated balance sheets in either Accounts payable, accrued expenses, and other liabilities or Other assets with changes in fair value included in Net realized gains (losses) in the consolidated statements of operations. Collateral held by brokers equal to a percentage of the total value of open futures contracts is included in the investment portfolio.
	Net investment income includes interest and dividend income and amortization of fixed maturity market premiums and discounts and is net of investment management and custody fees. For mortgage-backed securities, and any other holdings for which there is a prepayment risk, prepayment assumptions are evaluated and revised as necessary. Any adjustments required due to the resultant change in effective yields and maturities are recognized prospectively. Prepayment fees or call premiums that are only payable when a security is called prior to its maturity are earned when received and reflected in Net investment income.
	ACE participates in a securities lending program operated by a third-party banking institution whereby certain assets are loaned to qualified borrowers and from which we earn an incremental return. Borrowers provide collateral, in the form of either cash or approved securities, of 102 percent of the fair value of the loaned securities.  Each security loan is deemed to be an overnight transaction.  Cash collateral is invested in a collateral pool which is managed by the banking institution.  The collateral pool is subject to written investment guidelines with key objectives which include the safeguard of principal and adequate liquidity to meet anticipated redemptions. The fair value of the loaned securities is monitored on a daily basis, with additional collateral obtained or refunded as the fair value of the loaned securities changes. The collateral is held by the third-party banking institution, and the collateral can only be accessed in the event that the institution borrowing the securities is in default under the lending agreement. As a result of these restrictions, we consider our securities lending activities to be non-cash investing and financing activities. An indemnification agreement with the lending agent protects us in the event a borrower becomes insolvent or fails to return any of the securities on loan. The fair value of the securities on loan is included in fixed maturities and equity securities. The securities lending collateral is reported as a separate line in total assets with a related liability reflecting our obligation to return the collateral plus interest.
	Similar to securities lending arrangements, securities sold under repurchase agreements, whereby ACE sells securities and repurchases them at a future date for a predetermined price, are accounted for as collateralized investments and borrowings and are recorded at the contractual repurchase amounts plus accrued interest. Assets to be repurchased are the same, or substantially the same, as the assets transferred and the transferor, through right of substitution, maintains the right and ability to redeem the collateral on short notice. The fair value of the underlying securities is included in fixed maturities and equity securities. In contrast to securities lending programs, the use of cash received is not restricted. We report the obligation to return the cash as Short-term debt in the consolidated balance sheets.
	Refer to Note 4 for a discussion on the determination of fair value for ACE's various investment securities.
Cash	'
	Cash
	Cash includes cash on hand and deposits with an original maturity of three months or less at time of purchase. Cash held by external money managers is included in Short-term investments.
	We have agreements with a third-party bank provider which implemented two international multi-currency notional cash pooling programs. In each program, participating ACE entities establish deposit accounts in different currencies with the bank provider and each day the credit or debit balances in every account are notionally translated into a single currency (U.S. dollars) and then notionally pooled. The bank extends overdraft credit to any participating ACE entity as needed, provided that the overall notionally-pooled balance of all accounts in each pool at the end of each day is at least zero. Actual cash balances are not physically converted and are not commingled between legal entities. Any overdraft balances incurred under this program by an ACE entity would be guaranteed by ACE Limited (up to $300 million in the aggregate). Our syndicated letter of credit facility allows for same day drawings to fund a net pool overdraft should participating ACE entities overdraw contributed funds from the pool.
Goodwill and other intangible assets	'
	Goodwill and other intangible assets
	Goodwill represents the excess of the cost of acquisitions over the fair value of net assets acquired and is not amortized. Goodwill is assigned at acquisition to the applicable reporting unit of the acquired entities giving rise to the goodwill. Goodwill impairment tests are performed annually or more frequently if circumstances indicate a possible impairment.  For goodwill impairment testing, we use a qualitative assessment to determine whether it is more likely than not (i.e., more than a 50 percent probability) that the fair value of a reporting unit is greater than its carrying amount. If our assessment indicates less than a 50 percent probability that fair value exceeds carrying value, we quantitatively estimate a reporting unit's fair value. Goodwill recorded in connection with investments in partially-owned insurance companies is recorded in Investments in partially-owned insurance companies and is also measured for impairment annually.
	Indefinite lived intangible assets are not subject to amortization. Finite lived intangible assets are amortized over their useful lives, generally ranging from 1 to 20 years. The amortization of finite lived intangible assets is reported in Other (income) expense in the consolidated statements of operations. Intangible assets are regularly reviewed for indicators of impairment. Impairment is recognized if the carrying amount is not recoverable from its undiscounted cash flows and is measured as the difference between the carrying amount and fair value.
Unpaid losses and loss expenses	'
	Unpaid losses and loss expenses
	A liability is established for the estimated unpaid losses and loss expenses under the terms of, and with respect to, ACE's policies and agreements. Similar to premiums that are recognized as revenues over the coverage period of the policy, a liability for unpaid losses and loss expenses is recognized as expense when insured events occur over the coverage period of the policy. This liability includes a provision for both reported claims (case reserves) and incurred but not reported claims (IBNR reserves). IBNR reserve estimates are generally calculated by first projecting the ultimate cost of all losses that have occurred (expected losses), and then subtracting paid losses, case reserves, and loss expenses. The methods of determining such estimates and establishing the resulting liability are reviewed regularly and any adjustments are reflected in operations in the period in which they become known. Future developments may result in losses and loss expenses materially greater or less than recorded amounts.
	Except for net loss and loss expense reserves of $54 million net of discount, held at December 31, 2013, representing certain structured settlements for which the timing and amount of future claim payments are reliably determinable and $52 million, net of discount, of certain reserves for unsettled claims that are discounted in statutory filings, ACE does not discount its P&C loss reserves. This compares with reserves of $58 million for certain structured settlements and $47 million of certain reserves for unsettled claims at December 31, 2012. Structured settlements represent contracts purchased from life insurance companies primarily to settle workers' compensation claims, where payments to the claimant by the life insurance company are expected to be made in the form of an annuity. ACE retains the liability to the claimant in the event that the life insurance company fails to pay. At December 31, 2013, the gross liability due to claimants was $631 million, net of discount, and reinsurance recoverables due from the life insurance companies was $577 million, net of discount. For structured settlement contracts where payments are guaranteed regardless of claimant life expectancy, the amounts recoverable from the life insurance companies at December 31, 2013 are included in Other assets in the consolidated balance sheets, as they do not meet the requirements for reinsurance accounting.
	Included in unpaid losses and loss expenses are liabilities for asbestos and environmental (A&E) claims and expenses. These unpaid losses and loss expenses are principally related to claims arising from remediation costs associated with hazardous waste sites and bodily-injury claims related to asbestos products and environmental hazards. The estimation of these liabilities is particularly sensitive to changes in the legal environment including specific settlements that may be used as precedents to settle future claims. However, ACE does not anticipate future changes in laws and regulations in setting its A&E reserve levels.
	Prior period development arises from changes to loss estimates recognized in the current year that relate to loss reserves first reported in previous calendar years and excludes the effect of losses from the development of earned premiums from previous accident years.
	For purposes of analysis and disclosure, management views prior period development to be changes in the nominal value of loss estimates from period to period, net of premium and profit commission adjustments on loss sensitive contracts. Prior period development generally excludes changes in loss estimates that do not arise from the emergence of claims, such as those related to uncollectible reinsurance, interest, unallocated loss adjustment expenses, or foreign currency. Accordingly, specific items excluded from prior period development include the following: gains/losses related to foreign currency remeasurement; losses recognized from the early termination or commutation of reinsurance agreements that principally relate to the time value of money; changes in the value of reinsurance business assumed reflected in losses incurred but principally related to the time value of money; and losses that arise from changes in estimates of earned premiums from prior accident years. Except for foreign currency remeasurement, which is included in Net realized gains (losses), these items are included in current year losses.
Future policy benefits	'
	Future policy benefits
	The valuation of long-duration contract reserves requires management to make estimates and assumptions regarding expenses, mortality, persistency, and investment yields. Estimates are primarily based on historical experience and information provided by ceding companies and include a margin for adverse deviation. Interest rates used in calculating reserves range from less than 1.0 percent to 6.5 percent and less than 1.0 percent to 4.5 percent at December 31, 2013 and 2012, respectively. Actual results could differ materially from these estimates. Management monitors actual experience and where circumstances warrant, will revise assumptions and the related reserve estimates. Revisions are recorded in the period they are determined.
	Certain of our long-duration contracts are supported by assets that do not qualify for separate account reporting under GAAP. These assets are classified as trading securities and reported in Other investments and the offsetting liabilities are reported in Future policy benefits in the consolidated balance sheets. Changes in the fair value of separate account assets that do not qualify for separate account reporting under GAAP are reported in Other income (expense) and the offsetting movements in the liabilities are included in Policy benefits in the consolidated statements of operations.
Assumed reinsurance programs involving minimum benefit guarantees under annuity contracts	'
	Assumed reinsurance programs involving minimum benefit guarantees under annuity contracts
	ACE reinsures various death and living benefit guarantees associated with variable annuities issued primarily in the United States and Japan. Each reinsurance treaty covers variable annuities written during a limited period, typically not exceeding two years. We generally receive a monthly premium during the accumulation phase of the covered annuities (in-force) based on a percentage of either the underlying accumulated account values or the underlying accumulated guaranteed values. Depending on an annuitant's age, the accumulation phase can last many years. To limit our exposure under these programs, all reinsurance treaties include annual or aggregate claim limits and many include an aggregate deductible.
	The guarantees which are payable on death, referred to as guaranteed minimum death benefits (GMDB), principally cover shortfalls between accumulated account value at the time of an annuitant's death and either i) an annuitant's total deposits; ii) an annuitant's total deposits plus a minimum annual return; or iii) the highest accumulated account value attained at any policy anniversary date. In addition, a death benefit may be based on a formula specified in the variable annuity contract that uses a percentage of the growth of the underlying contract value. Liabilities for GMDBs are based on cumulative assessments or premiums to date multiplied by a benefit ratio that is determined by estimating the present value of benefit payments and related adjustment expenses divided by the present value of cumulative assessment or expected premiums during the contract period.
	Under reinsurance programs covering GLBs, we assume the risk of guaranteed minimum income benefits (GMIB) and guaranteed minimum accumulation benefits (GMAB) associated with variable annuity contracts. The GMIB risk is triggered if, at the time the contract holder elects to convert the accumulated account value to a periodic payment stream (annuitize), the accumulated account value is not sufficient to provide a guaranteed minimum level of monthly income. The GMAB risk is triggered if, at contract maturity, the contract holder's account value is less than a guaranteed minimum value. Our GLB reinsurance product meets the definition of a derivative for accounting purposes and is carried at fair value with changes in fair value recognized in income and classified as described below. As the assuming entity, we are obligated to provide coverage until the earlier of the expiration of the underlying guaranteed benefit or the treaty expiration date. Premiums received under the reinsurance treaties are classified as premium. Expected losses allocated to premiums received are classified as policy benefits and valued similar to GMDB reinsurance. Other changes in fair value, principally arising from changes in expected losses allocated to expected future premiums, are classified as Net realized gains (losses). Fair value represents management's estimate of exit price and thus includes a risk margin. We may recognize a realized loss for other changes in fair value due to adverse changes in the capital markets (i.e., declining interest rates and/or declining equity markets) and changes in policyholder behavior (i.e., increased annuitization or decreased lapse rates) although we expect the business to be profitable. We believe this presentation provides the most meaningful disclosure of changes in the underlying risk within the GLB reinsurance programs for a given reporting period.
Deposit assets and liabilities	'
	Deposit assets and liabilities
	Deposit assets arise from ceded reinsurance contracts purchased that do not transfer significant underwriting or timing risk. Under deposit accounting, consideration received or paid, excluding non-refundable fees, is recorded as a deposit asset or liability in the balance sheet as opposed to recording premiums and losses in the statement of operations. Interest income on deposits, representing the consideration received or to be received in excess of cash payments related to the deposit contract, is earned based on an effective yield calculation. The calculation of the effective yield is based on the amount and timing of actual cash flows at the balance sheet date and the estimated amount and timing of future cash flows. The effective yield is recalculated periodically to reflect revised estimates of cash flows. When a change in the actual or estimated cash flows occurs, the resulting change to the carrying amount of the deposit asset is reported as income or expense. Deposit assets of $100 million and $138 million at December 31, 2013 and 2012, respectively, are reflected in Other assets in the consolidated balance sheets and the accretion of deposit assets related to interest pursuant to the effective yield calculation is reflected in Net investment income in the consolidated statements of operations.
	Non-refundable fees are earned based on contract terms. Non-refundable fees paid but unearned are reflected in Other assets in the consolidated balance sheets and earned fees are reflected in Other (income) expense in the consolidated statements of operations.
	Deposit liabilities include reinsurance deposit liabilities of $131 million and $283 million and contract holder deposit funds of $699 million and $548 million at December 31, 2013 and 2012, respectively. Deposit liabilities are reflected in Accounts payable, accrued expenses, and other liabilities in the consolidated balance sheets. The reinsurance deposit liabilities arise from contracts sold for which there is not a significant transfer of risk. At contract inception, the deposit liability equals net cash received. An accretion rate is established based on actuarial estimates whereby the deposit liability is increased to the estimated amount payable over the contract term. The deposit accretion rate is the rate of return required to fund expected future payment obligations. We periodically reassess the estimated ultimate liability and related expected rate of return. Changes to the deposit liability are generally reflected through Interest expense to reflect the cumulative effect of the period the contract has been in force, and by an adjustment to the future accretion rate of the liability over the remaining estimated contract term.
	Contract holder deposit funds represent a liability for investment contracts sold that do not meet the definition of an insurance contract, and certain of these contracts are sold with a guaranteed rate of return. The liability equals accumulated policy account values, which consist of the deposit payments plus credited interest less withdrawals and amounts assessed through the end of the period.
Foreign currency remeasurement and translation	'
	Foreign currency remeasurement and translation
	The functional currency for each of our foreign operations is generally the currency of the local operating environment. Transactions in currencies other than a foreign operation's functional currency are remeasured into the functional currency and the resulting foreign exchange gains and losses are reflected in Net realized gains (losses) in the consolidated statements of operations. Functional currency assets and liabilities are translated into the reporting currency, U.S. dollars, using period end exchange rates and the related translation adjustments are recorded as a separate component of AOCI. Functional statement of operations amounts expressed in functional currencies are translated using average exchange rates.
Administrative expenses	'
	Administrative expenses
	Administrative expenses generally include all operating costs other than policy acquisition costs. The Insurance – North American P&C segment manages and uses an in-house third-party claims administrator, ESIS Inc. (ESIS).  ESIS performs claims management and risk control services for domestic and international organizations that self-insure P&C exposures as well as internal P&C exposures.  The net operating results of ESIS are included within Administrative expenses in the consolidated statements of operations and were $25 million, $23 million, and $21 million for the years ended December 31, 2013, 2012, and 2011, respectively.
Income taxes	'
	Income taxes
	Income taxes have been recorded related to those operations subject to income taxes. Deferred tax assets and liabilities result from temporary differences between the amounts recorded in the consolidated financial statements and the tax basis of our assets and liabilities. Refer to Note 8 for additional information. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance against deferred tax assets is recorded if it is more likely than not that all, or some portion, of the benefits related to deferred tax assets will not be realized. The valuation allowance assessment considers tax planning strategies, where applicable.
	We recognize uncertain tax positions deemed more likely than not of being sustained upon examination.  Recognized income tax positions are measured at the largest amount that is greater than 50 percent likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.
Earnings per share	'
	Earnings per share
	Basic earnings per share is calculated using the weighted-average shares outstanding including participating securities with non-forfeitable rights to dividends such as unvested restricted stock. All potentially dilutive securities including stock options are excluded from the basic earnings per share calculation. In calculating diluted earnings per share, the weighted-average shares outstanding is increased to include all potentially dilutive securities. Basic and diluted earnings per share are calculated by dividing Net income by the applicable weighted-average number of shares outstanding during the year.
Cash flow information	'
	Cash flow information
	Premiums received and losses paid associated with the GLB reinsurance products, which as discussed previously meet the definition of a derivative instrument for accounting purposes, are included within Cash flows from operating activities.  Cash flows, such as settlements and collateral requirements, associated with GLB and all other derivative instruments are included on a net basis within Cash flows from investing activities. Purchases, sales, and maturities of short-term investments are recorded on a net basis within Cash flows from investing activities.
Derivatives	'
	Derivatives
	ACE recognizes all derivatives at fair value in the consolidated balance sheets and participates in derivative instruments in two principal ways:
	(i) To sell protection to customers as an insurance or reinsurance contract that meets the definition of a derivative for accounting purposes. For 2013 and 2012, the reinsurance of GLBs was our primary product falling into this category; and
	(ii) To mitigate financial risks, principally arising from investment holdings, products sold, or assets and liabilities held in foreign currencies. For these instruments, changes in assets or liabilities measured at fair value are recorded as realized gains or losses in the consolidated statement of operations.
	We did not designate any derivatives as accounting hedges during 2013, 2012, or 2011.
Share-based compensation	'
	Share-based compensation
	ACE measures and records compensation cost for all share-based payment awards at grant-date fair value. Compensation costs are recognized for share-based payment awards with only service conditions that have graded vesting schedules on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in substance, multiple awards. Refer to Note 12 for additional information.
New accounting pronouncements	'

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Schedule Of Amortized Cost And Fair Value Of Fixed Maturities And Related OTTI Recognized In AOCI	'
	31-Dec-13	Amortized				Gross			Gross				Fair				OTTI Recognized
		Cost				Unrealized			Unrealized				Value				in AOCI
	(in millions of U.S. dollars)					Appreciation			Depreciation
	Available for sale
	U.S. Treasury and agency	$	2,946			$	62		$	(59	)		$	2,949			$	—
	Foreign	14,336				377			(122		)		14,591				—
	Corporate securities	16,825				777			(132		)		17,470				(6		)
	Mortgage-backed securities	10,937				184			(227		)		10,894				(34		)
	States, municipalities, and political subdivisions	3,362				65			(77		)		3,350				—
		$	48,406			$	1,465		$	(617	)		$	49,254			$	(40	)
	Held to maturity
	U.S. Treasury and agency	$	820			$	16		$	(4	)		$	832			$	—
	Foreign	864				33			—				897				—
	Corporate securities	1,922				83			—				2,005				—
	Mortgage-backed securities	1,341				39			(1		)		1,379				—
	States, municipalities, and political subdivisions	1,151				16			(17		)		1,150				—
		$	6,098			$	187		$	(22	)		$	6,263			$	—
Schedule Of Fixed Maturities By Contractual Maturity	'
	The following table presents fixed maturities by contractual maturity:
		31-Dec							31-Dec
						2013							2012
	(in millions of U.S. dollars)	Amortized Cost				Fair Value			Amortized Cost				Fair Value
	Available for sale
	Due in 1 year or less	$	2,387			$	2,411		$	1,887			$	1,906
	Due after 1 year through 5 years	14,139				14,602			13,411				14,010
	Due after 5 years through 10 years	16,200				16,535			15,032				16,153
	Due after 10 years	4,743				4,812			4,285				4,764
		37,469				38,360			34,615				36,833
	Mortgage-backed securities	10,937				10,894			10,051				10,473
		$	48,406			$	49,254		$	44,666			$	47,306
	Held to maturity
	Due in 1 year or less	$	401			$	405		$	656			$	659
	Due after 1 year through 5 years	2,284				2,363			1,870				1,950
	Due after 5 years through 10 years	1,686				1,723			2,119				2,267
	Due after 10 years	386				393			597				641
		4,757				4,884			5,242				5,517
	Mortgage-backed securities	1,341				1,379			2,028				2,116
		$	6,098			$	6,263		$	7,270			$	7,633
Schedule Of Cost And Fair Value Of Equity Securities	'
		31-Dec				31-Dec
	(in millions of U.S. dollars)	2013				2012
	Cost	$	841			$	707
	Gross unrealized appreciation	63				41
	Gross unrealized depreciation	(67		)		(4		)
	Fair value	$	837			$	744
Schedule Of Default Assumptions By Moody's Rating Category	'
	The following table presents default assumptions by Moody's rating category (historical mean default rate provided for comparison):
	Moody's Rating Category	1-in-100 Year Default Rate			Historical Mean Default Rate
	Investment Grade:
	Aaa-Baa	0.0-1.4%			0.0-0.3%
	Below Investment Grade:
	Ba	4.9	%		1.1	%
	B	12.8	%		3.4	%
	Caa-C	53.2	%		13.8	%
Schedule Of Significant Assumptions For Future Cash Flows For Mortgage Backed Securities	'
Schedule Of Net Realized Gains (Losses) And The Losses Included In Net Realized Gains (Losses) And OCI	'
	The following table presents the Net realized gains (losses) and the losses included in Net realized gains (losses) and OCI as a result of conditions which caused us to conclude the decline in fair value of certain investments was “other-than-temporary” and the change in net unrealized appreciation (depreciation) of investments:
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012			2011
	Fixed maturities:
	OTTI on fixed maturities, gross	$	(18	)		$	(26	)	$	(61	)
	OTTI on fixed maturities recognized in OCI (pre-tax)	—				1			15
	OTTI on fixed maturities, net	(18		)		(25		)	(46		)
	Gross realized gains excluding OTTI	237				388			410
	Gross realized losses excluding OTTI	(129		)		(133		)	(200		)
	Total fixed maturities	90				230			164
	Equity securities:
	OTTI on equity securities	(2		)		(5		)	(1		)
	Gross realized gains excluding OTTI	21				11			15
	Gross realized losses excluding OTTI	(4		)		(2		)	(5		)
	Total equity securities	15				4			9
	OTTI on other investments	(2		)		(7		)	(3		)
	Foreign exchange gains (losses)	29				(16		)	(13		)
	Investment and embedded derivative instruments	78				(6		)	(143		)
	Fair value adjustments on insurance derivative	878				171			(779		)
	S&P put options and futures	(579		)		(297		)	(4		)
	Other derivative instruments	(2		)		(4		)	(4		)
	Other	(3		)		3			(22		)
	Net realized gains (losses)	504				78			(795		)
	Change in net unrealized appreciation (depreciation) on investments:
	Fixed maturities available for sale	(1,798		)		1,099			569
	Fixed maturities held to maturity	(82		)		(94		)	(89		)
	Equity securities	(41		)		61			(47		)
	Other	54				50			40
	Income tax (expense) benefit	408				(198		)	(157		)
	Change in net unrealized appreciation (depreciation) on investments	(1,459		)		918			316
	Total net realized gains (losses) and change in net unrealized appreciation (depreciation) on investments	$	(955	)		$	996		$	(479	)
Schedule Of Roll-Forward Of Pre-Tax Credit Losses Related To Fixed Maturities For Which A Portion Of OTTI Was Recognized In OCI	'
	The following table presents a roll-forward of pre-tax credit losses related to fixed maturities for which a portion of OTTI was recognized in OCI:
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012			2011
	Balance of credit losses related to securities still held – beginning of year	$	43			$	74		$	137
	Additions where no OTTI was previously recorded	9				8			12
	Additions where an OTTI was previously recorded	3				12			8
	Reductions for securities sold during the period	(18		)		(51		)	(83		)
	Balance of credit losses related to securities still held – end of year	$	37			$	43		$	74
Schedule Of Other Investments	'
						31-Dec							31-Dec
						2013							2012
	(in millions of U.S. dollars)	Fair Value				Cost			Fair Value				Cost
	Investment funds	$	428			$	278		$	395			$	278
	Limited partnerships	576				424			531				398
	Partially-owned investment companies	1,284				1,284			1,186				1,187
	Life insurance policies	180				180			148				148
	Policy loans	179				179			164				164
	Trading securities	276				273			243				242
	Other	53				53			49				48
	Total	$	2,976			$	2,671		$	2,716			$	2,465
Schedule Of Partially Owned Insurance Companies	'
		31-Dec										31-Dec
		2013										2012
	(in millions of U.S. dollars, except percentages)	Carrying Value				Issued			Ownership Percentage			Carrying Value				Issued Share Capital				Ownership Percentage			Domicile
						Share
						Capital
	Huatai Group	$	365			$	631		20	%		$	350			$	474			20	%		China
	Huatai Life Insurance Company	84				379			20	%		84				205				20	%		China
	Freisenbruch-Meyer	9				5			40	%		9				5				40	%		Bermuda
	ACE Cooperative Insurance Co. – Saudi Arabia	10				27			30	%		9				27				30	%		Saudi Arabia
	Russian Reinsurance Company	2				4			23.3	%		2				4				23.3	%		Russia
	Total	$	470			$	1,046					$	454			$	715
Schedule Of Aggregate Fair Value And Gross Unrealized Loss By Length Of Time The Security Has Continuously Been In An Unrealized Loss Position	'
	The following tables present, for all securities in an unrealized loss position (including securities on loan), the aggregate fair value and gross unrealized loss by length of time the security has continuously been in an unrealized loss position:
		0 – 12 Months							Over 12 Months								Total
	31-Dec-13	Fair Value				Gross			Fair Value				Gross				Fair Value				Gross
	(in millions of U.S. dollars)					Unrealized Loss							Unrealized Loss								Unrealized Loss
	U.S. Treasury and agency	$	1,794			$	(57	)	$	31			$	(6	)		$	1,825			$	(63	)
	Foreign	4,621				(114		)	201				(8		)		4,822				(122		)
	Corporate securities	3,836				(118		)	194				(14		)		4,030				(132		)
	Mortgage-backed securities	5,248				(197		)	384				(31		)		5,632				(228		)
	States, municipalities, and political subdivisions	2,164				(90		)	84				(4		)		2,248				(94		)
	Total fixed maturities	17,663				(576		)	894				(63		)		18,557				(639		)
	Equity securities	498				(67		)	—				—				498				(67		)
	Other investments	67				(9		)	—				—				67				(9		)
	Total	$	18,228			$	(652	)	$	894			$	(63	)		$	19,122			$	(715	)
		0 – 12 Months							Over 12 Months								Total
	31-Dec-12	Fair Value				Gross			Fair Value				Gross				Fair Value				Gross
	(in millions of U.S. dollars)					Unrealized Loss							Unrealized Loss								Unrealized Loss
	U.S. Treasury and agency	$	440			$	(1	)	$	—			$	—			$	440			$	(1	)
	Foreign	1,234				(8		)	88				(6		)		1,322				(14		)
	Corporate securities	1,026				(23		)	85				(8		)		1,111				(31		)
	Mortgage-backed securities	855				(4		)	356				(32		)		1,211				(36		)
	States, municipalities, and political subdivisions	316				(3		)	48				(4		)		364				(7		)
	Total fixed maturities	3,871				(39		)	577				(50		)		4,448				(89		)
	Equity securities	29				(4		)	—				—				29				(4		)
	Other investments	68				(5		)	—				—				68				(5		)
	Total	$	3,968			$	(48	)	$	577			$	(50	)		$	4,545			$	(98	)
Schedule Of Sources Of Net Investment Income	'
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012			2011
	Fixed maturities	$	2,093			$	2,134		$	2,196
	Short-term investments	29				28			43
	Equity securities	37				34			36
	Other	105				104			62
	Gross investment income	2,264				2,300			2,337
	Investment expenses	(120		)		(119		)	(95		)
	Net investment income	$	2,144			$	2,181		$	2,242
Schedule Of Components Of Restricted Assets	'
	The following table presents the components of restricted assets:
		31-Dec				31-Dec
	(in millions of U.S. dollars)	2013				2012
	Trust funds	$	11,315			$	11,389
	Deposits with non-U.S. regulatory authorities	1,970				2,133
	Assets pledged under repurchase agreements	1,435				1,401
	Deposits with U.S. regulatory authorities	1,334				1,338
	Other pledged assets	391				456
		$	16,445			$	16,717

Fair_value_measurements_Tables

Fair value measurements (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Financial Instruments Measured At Fair Value On A Recurring Basis	'
	The following tables present, by valuation hierarchy, the financial instruments measured at fair value on a recurring basis:
	31-Dec-13	Level 1				Level 2				Level 3				Total
	(in millions of U.S. dollars)
	Assets:
	Fixed maturities available for sale
	U.S. Treasury and agency	$	1,626			$	1,323			$	—			$	2,949
	Foreign	223				14,324				44				14,591
	Corporate securities	—				17,304				166				17,470
	Mortgage-backed securities	—				10,886				8				10,894
	States, municipalities, and political subdivisions	—				3,350				—				3,350
		1,849				47,187				218				49,254
	Equity securities	373				460				4				837
	Short-term investments	953				803				7				1,763
	Other investments	305				231				2,440				2,976
	Securities lending collateral	—				1,632				—				1,632
	Investment derivative instruments	19				—				—				19
	Other derivative instruments	—				6				—				6
	Separate account assets	1,145				81				—				1,226
	Total assets measured at fair value	$	4,644			$	50,400			$	2,669			$	57,713
	Liabilities:
	Investment derivative instruments	$	6			$	—			$	—			$	6
	Other derivative instruments	60				2				—				62
	GLB(1)	—				—				193				193
	Total liabilities measured at fair value	$	66			$	2			$	193			$	261
	(1)	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. Refer to Note 5 c) for additional information.
	December 31, 2012	Level 1				Level 2				Level 3				Total
	(in millions of U.S. dollars)
	Assets:
	Fixed maturities available for sale
	U.S. Treasury and agency	$	2,050			$	1,685			$	—			$	3,735
	Foreign	222				13,431				60				13,713
	Corporate securities	20				16,586				102				16,708
	Mortgage-backed securities	—				10,460				13				10,473
	States, municipalities, and political subdivisions	—				2,677				—				2,677
		2,292				44,839				175				47,306
	Equity securities	253				488				3				744
	Short-term investments	1,503				725				—				2,228
	Other investments	268				196				2,252				2,716
	Securities lending collateral	—				1,791				—				1,791
	Investment derivative instruments	11				—				—				11
	Other derivative instruments	(6		)		30				—				24
	Separate account assets	872				71				—				943
	Total assets measured at fair value	$	5,193			$	48,140			$	2,430			$	55,763
	Liabilities:
	GLB(1)	$	—			$	—			$	1,119			$	1,119
	(1)	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. Refer to Note 5 c) for additional information.
Fair Value And Maximum Future Funding Commitments Related To Investments	'
	The following table presents, by investment category, the expected liquidation period, fair value, and maximum future funding commitments of alternative investments:
				31-Dec								31-Dec
				2013								2012
	(in millions of U.S. dollars)	Expected		Fair Value				Maximum				Fair Value				Maximum
		Liquidation						Future Funding								Future Funding
		Period of Underlying Assets						Commitments								Commitments
	Financial	5 to 9 Years		$	256			$	129			$	225			$	111
	Real estate	3 to 9 Years		322				92				292				62
	Distressed	6 to 9 Years		180				230				192				152
	Mezzanine	6 to 9 Years		276				252				284				279
	Traditional	3 to 8 Years		813				456				711				587
	Vintage	1 to 3 Years		13				—				14				—
	Investment funds	Not Applicable		428				—				395				—
				$	2,288			$	1,159			$	2,113			$	1,191
Schedule Of Significant Unobservable Inputs Used In Level 3 Liability Valuations	'
	The following table presents the significant unobservable inputs used in the Level 3 liability valuations. Excluded from the table below are inputs used to determine the fair value of Level 3 assets which are based on single broker quotes or net asset value and contain no quantitative unobservable inputs developed by management.
	(in millions of U.S. dollars, except for percentages)	Fair Value at				Valuation		Significant		Ranges
		December 31, 2013				Technique		Unobservable Inputs
	GLB(1)	$	193			Actuarial model		Lapse rate		1% – 30%
								Annuitization rate		0% – 55%
	(1)	Discussion of the most significant inputs used in the fair value measurement of GLB and the sensitivity of those assumptions is included within Note 4 a) Guaranteed living benefits.
Financial Instruments Measured At Fair Value Using Significant Unobservable Inputs	'
	The following tables present a reconciliation of the beginning and ending balances of financial instruments measured at fair value using significant unobservable inputs (Level 3):
		Assets																								Liabilities
		Available-for-Sale Debt Securities													Equity				Short-term investments			Other				GLB(1)
	Year Ended December 31, 2013	Foreign				Corporate				MBS					securities							investments
	(in millions of U.S. dollars)					securities
	Balance, beginning of year	$	60			$	102			$	13				$	3			$	—		$	2,252			$	1,119
	Transfers into Level 3	36				47				—					8				8			—				—
	Transfers out of Level 3	(54		)		(31		)		—					(1		)		(2		)	—				—
	Change in Net Unrealized Gains (Losses) included in OCI	—				—				—					(6		)		—			45				—
	Net Realized Gains/Losses	1				(2		)		—					4				—			(2		)		(926		)
	Purchases	24				75				—					2				3			551				—
	Sales	(21		)		(7		)		(3		)			(6		)		(1		)	(10		)		—
	Settlements	(2		)		(18		)		(2		)			—				(1		)	(396		)		—
	Balance, end of year	$	44			$	166			$	8				$	4			$	7		$	2,440			$	193
	Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	—			$	(2	)		$	—				$	—			$	—		$	(2	)		$	(926	)
	(1)	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. Refer to Note 5 c) for additional information.
		Assets																														Liabilities
		Available-for-Sale Debt Securities																				Equity			Other				Other			GLB(1)
	Year Ended December 31, 2012	U.S.				Foreign				Corporate				MBS				States,				securities			investments				derivative
		Treasury								securities								municipalities,											instruments
		and																and political
	(in millions of U.S. dollars)	Agency																subdivisions
	Balance, beginning of year	$	5			$	33			$	134			$	28			$	1			$	13		$	1,877			$	3		$	1,319
	Transfers into Level 3	—				49				37				22				1				2			53				—			—
	Transfers out of Level 3	(4		)		(13		)		(46		)		(35		)		(1		)		(11		)	—				—			—
	Change in Net Unrealized Gains (Losses) included in OCI	—				(1		)		6				—				—				—			55				—			—
	Net Realized Gains/Losses	—				—				(1		)		—				—				—			(7		)		(4		)	(200		)
	Purchases	—				46				24				9				—				4			520				3			—
	Sales	—				(53		)		(19		)		(7		)		—				(5		)	(9		)		—			—
	Settlements	(1		)		(1		)		(33		)		(4		)		(1		)		—			(237		)		(2		)	—
	Balance, end of year	$	—			$	60			$	102			$	13			$	—			$	3		$	2,252			$	—		$	1,119
	Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	—			$	—			$	—			$	—			$	—			$	—		$	(7	)		$	—		$	(200	)
	(1)	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. The liability for GLB reinsurance was $1.4 billion at December 31, 2012 and $1.5 billion at December 31, 2011, which includes a fair value derivative adjustment of $1.1 billion and $1.3 billion, respectively.
						Assets																										Liabilities
						Available-for-Sale Debt Securities																										GLB(1)
	Year Ended December 31, 2011	U.S.				Foreign				Corporate				MBS				States,				Equity			Other				Other
		Treasury								securities								municipalities,				securities			investments				derivative
		and																and political											instruments
	(in millions of U.S. dollars)	Agency																subdivisions
	Balance, beginning of year	$	—			$	26			$	115			$	39			$	2			$	13		$	1,432			$	4		$	507
	Transfers into Level 3	—				9				42				4				—				—			—				—			—
	Transfers out of Level 3	—				(18		)		(4		)		(48		)		—				—			—				—			—
	Change in Net Unrealized Gains (Losses) included in OCI	—				(1		)		(2		)		—				—				(1		)	93				—			—
	Net Realized Gains/Losses	—				—				(3		)		—				—				4			(3		)		2			812
	Purchased	5				23				32				59				—				5			602				—			—
	Sales	—				(3		)		(27		)		(17		)		—				(8		)	(55		)		—			—
	Settlements	—				(3		)		(19		)		(9		)		(1		)		—			(192		)		(3		)	—
	Balance, end of year	$	5			$	33			$	134			$	28			$	1			$	13		$	1,877			$	3		$	1,319
	Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	—			$	—			$	—			$	—			$	—			$	—		$	(3	)		$	(1	)	$	812
	(1)	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. The liability for GLB reinsurance was $1.5 billion at December 31, 2011 and $648 million at December 31, 2010, which includes a fair value derivative adjustment of $1.3 billion and $507 million, respectively.
Carrying Values And Fair Values Of Financial Instruments Not Measured At Fair Value	'
	31-Dec-13	Fair Value															Carrying Value
	(in millions of U.S. dollars)	Level 1				Level 2				Level 3				Total
	Assets:
	Fixed maturities held to maturity
	U.S. Treasury and agency	$	596			$	236			$	—			$	832		$	820
	Foreign	—				897				—				897			864
	Corporate securities	—				1,990				15				2,005			1,922
	Mortgage-backed securities	—				1,379				—				1,379			1,341
	States, municipalities, and political subdivisions	—				1,150				—				1,150			1,151
		596				5,652				15				6,263			6,098
	Partially-owned insurance companies	—				—				470				470			470
	Total assets	$	596			$	5,652			$	485			$	6,733		$	6,568
	Liabilities:
	Short-term debt	$	—			$	1,913			$	—			$	1,913		$	1,901
	Long-term debt	—				4,088				—				4,088			3,807
	Trust preferred securities	—				438				—				438			309
	Total liabilities	$	—			$	6,439			$	—			$	6,439		$	6,017
	31-Dec-12	Fair Value															Carrying Value
	(in millions of U.S. dollars)	Level 1				Level 2				Level 3				Total
	Assets:
	Fixed maturities held to maturity
	U.S. Treasury and agency	$	619			$	464			$	—			$	1,083		$	1,044
	Foreign	—				964				—				964			910
	Corporate securities	—				2,257				18				2,275			2,133
	Mortgage-backed securities	—				2,116				—				2,116			2,028
	States, municipalities, and political subdivisions	—				1,195				—				1,195			1,155
		619				6,996				18				7,633			7,270
	Partially-owned insurance companies	—				—				454				454			454
	Total assets	$	619			$	6,996			$	472			$	8,087		$	7,724
	Liabilities:
	Short-term debt	$	—			$	1,401			$	—			$	1,401		$	1,401
	Long-term debt	—				3,916				—				3,916			3,360
	Trust preferred securities	—				446				—				446			309
	Total liabilities	$	—			$	5,763			$	—			$	5,763		$	5,070

Reinsurance_Tables

Reinsurance (Tables)	12 Months Ended
	Dec. 31, 2013
Reinsurance Disclosures [Abstract]	'
Schedule of direct, assumed and ceded premiums	'
	The following table presents direct, assumed, and ceded premiums:
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012				2011
	Premiums written
	Direct	$	19,212			$	18,144			$	17,626
	Assumed		3,616				3,449				3,205
	Ceded		(5,803	)			(5,518	)			(5,459	)
	Net	$	17,025			$	16,075			$	15,372
	Premiums earned
	Direct	$	18,856			$	17,802			$	17,534
	Assumed		3,479				3,302				3,349
	Ceded		(5,722	)			(5,427	)			(5,496	)
	Net	$	16,613			$	15,677			$	15,387
Schedule of reinsurance recoverable on losses and loss expenses	'
			31-Dec					31-Dec
	(in millions of U.S. dollars)		2013					2012
	Reinsurance recoverable on unpaid losses and loss expenses (1)			$	10,612				$	11,399
	Reinsurance recoverable on paid losses and loss expenses (1)			615					679
	Net reinsurance recoverable on losses and loss expenses			$	11,227				$	12,078
Schedule of reinsurance recoverable and provision by category of reinsurer	'
	(in millions of U.S. dollars, except percentages)	2013					Provision					% of Gross
	Categories
	Largest reinsurers		$	5,117				$	78			1.5	%
	Other reinsurers balances rated A- or better		2,901					36				1.2	%
	Other reinsurers balances with ratings lower than A- or not rated		587					103				17.5	%
	Other pools and government agencies		338					21				6.2	%
	Structured settlements		577					12				2.1	%
	Captives		1,762					14				0.8	%
	Other		335					126				37.6	%
	Total		$	11,617				$	390			3.4	%
Schedule of income and expenses relating to GMDB and GLB reinsurance	'
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012				2011
	GMDB
	Net premiums earned	$	77			$	85			$	98
	Policy benefits and other reserve adjustments	$	73			$	60			$	59
	GLB
	Net premiums earned	$	149			$	160			$	163
	Policy benefits and other reserve adjustments	27				61				47
	Net realized gains (losses)	929				203				(812		)
	Gain (loss) recognized in income	$	1,051			$	302			$	(696	)
	Net cash received	$	126			$	149			$	161
	Net (increase) decrease in liability	$	925			$	153			$	(857	)

Intangible_Assets_Tables

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill roll-forward by business segment	'
	The following table presents a roll-forward of Goodwill by segment:
	(in millions of U.S. dollars)	Insurance – North American			Insurance – North American Agriculture			Insurance – Overseas General			Global Reinsurance		Life			ACE Consolidated
		P&C
	Balance at December 31, 2011	$	1,216		$	134		$	1,603		$	365	$	830		$	4,148
	Purchase price allocation adjustment	—			—			—			—		4			4
	Acquisition of JaPro	—			—			123			—		—			123
	Foreign exchange revaluation and other	3			—			38			—		3			44
	Balance at December 31, 2012	$	1,219		$	134		$	1,764		$	365	$	837		$	4,319
	Acquisition of Fianzas Monterrey	—			—			135			—		—			135
	Acquisition of ABA Seguros	—			—			283			—		—			283
	Foreign exchange revaluation and other	(4		)	—			(128		)	—		(2		)	(134		)
	Balance at December 31, 2013	$	1,215		$	134		$	2,054		$	365	$	835		$	4,603
Schedule of VOBA roll-foward	'
	The following table presents a roll-forward of VOBA:
	(in millions of U.S. dollars)	2013			2012			2011
	Balance, beginning of year	$	614		$	676		$	634
	Acquisition of New York Life's Korea operations and Hong Kong operations	—			—			151
	Amortization expense	(64		)	(82		)	(108		)
	Foreign exchange revaluation	(14		)	20			(1		)
	Balance, end of year	$	536		$	614		$	676
Schedule of estimated amortization expense related to VOBA	'
	The following table presents estimated amortization expense related to other intangible assets and VOBA for the next five years:
	For the Year Ending December 31	Other intangible assets			VOBA
	(in millions of U.S. dollars)
	2014	$	81		$	55
	2015	62			50
	2016	55			45
	2017	52			40
	2018	49			35
	Total	$	299		$	225

Unpaid_losses_and_loss_expense1

Unpaid losses and loss expenses (Tables)	12 Months Ended
	Dec. 31, 2013
Unpaid Losses And Loss Expenses [Abstract]	'
Schedule Of Unpaid Losses And Loss Expenses Roll Forward	'
	The following table presents a reconciliation of unpaid losses and loss expenses:
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012					2011
	Gross unpaid losses and loss expenses, beginning of year		$	37,946			$	37,477				$	37,391
	Reinsurance recoverable on unpaid losses(1)		(11,399		)		(11,602		)			(12,149		)
	Net unpaid losses and loss expenses, beginning of year		26,547				25,875					25,242
	Acquisition of subsidiaries		86				14					92
	Total		26,633				25,889					25,334
	Net losses and loss expenses incurred in respect of losses occurring in:
	Current year		9,878				10,132					10,076
	Prior years		(530		)		(479		)			(556		)
	Total		9,348				9,653					9,520
	Net losses and loss expenses paid in respect of losses occurring in:
	Current year		3,942				4,325					4,209
	Prior years		5,035				4,894					4,657
	Total		8,977				9,219					8,866
	Foreign currency revaluation and other		(173		)		224					(113		)
	Net unpaid losses and loss expenses, end of year		26,831				26,547					25,875
	Reinsurance recoverable on unpaid losses(1)		10,612				11,399					11,602
	Gross unpaid losses and loss expenses, end of year		$	37,443			$	37,946				$	37,477
	(1) Net of provision for uncollectible reinsurance.
Schedule Of Asbestos Environmental Loss Roll Forward	'
	expense reserves for A&E exposures, and the provision for uncollectible paid and unpaid reinsurance recoverables:
		Asbestos									Environmental								Total
	(in millions of U.S. dollars)	Gross				Net					Gross				Net				Gross					Net
	Balance at December 31, 2012 (1)		$	1,886			$	970				$	194			$	136			$	2,080				$	1,106
	Incurred activity		125				96					119				75				244					171			(2)
	Paid activity		(367		)		(140		)			(118		)		(86		)		(485		)			(226		)
	Balance at December 31, 2013		$	1,644			$	926				$	195			$	125			$	1,839				$	1,051
	-1	Balances at December 31, 2012 have been adjusted to present claims in a manner consistent with balances disclosed at December 31, 2013.
	(2)	Excludes unallocated loss expenses.
Schedule Of Brandywine Asbestos Environmental Loss Roll Forward	'
	The following table presents a roll-forward of net loss reserves, allocated loss expense reserves, and provision for uncollectible paid and unpaid reinsurance recoverables in respect of Brandywine operations only, including the impact of the Brandywine NICO Agreement:
		Brandywine													NICO Coverage				Net of NICO Coverage
	(in millions of U.S. dollars)	A&E				Other				(1)	Total
	Balance at December 31, 2012		$	852			$	421				$	1,273			$	18		$	1,255
	Incurred activity		158				9					167				—			167			(2)
	Paid activity		(194		)		(63		)			(257		)		(18		)	(239		)
	Balance at December 31, 2013		$	816			$	367				$	1,183			$	—		$	1,183
	(1)	Other consists primarily of workers' compensation, non-A&E general liability losses, and provision for uncollectible reinsurance on non-A&E business.
	(2)	Excludes $(1) million of unallocated loss expenses (benefits).
	The
Schedule Of Westchester Specialty Asbestos Environmental Loss Roll Forward	'
	following table presents a roll-forward of net loss reserves, allocated loss expense reserves, and provision for uncollectible paid and unpaid reinsurance recoverables in respect of 1996 and prior Westchester Specialty operations only, including the impact of the Westchester NICO Agreement:
		Westchester Specialty													NICO Coverage				Net of NICO Coverage
	(in millions of U.S. dollars)	A&E				Other					Total
	Balance at December 31, 2012		$	151			$	44				$	195			$	158			$	37
	Incurred activity		14				(11		)			3				2				1			(1)
	Paid activity		-19				—					-19				-19				—
	Balance at December 31, 2013		$	146			$	33				$	179			$	141			$	38
	-1	Excludes $4 million of unallocated loss expenses.
	Th

Taxation_Tables

Taxation (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Schedule of components of income tax provision	'
	The following table presents the provision for income taxes:
		Years Ended December 31
	(in millions of U.S. dollars)	2013			2012			2011
	Current tax expense	$	231		$	305		$	485
	Deferred tax expense (benefit)	249			(35		)	17
	Provision for income taxes	$	480		$	270		$	502
Reconciliation schedule of the difference between the provision for income taxes and the expected tax provision at the Swiss statutory income tax rate	'
	The following table presents a reconciliation of the difference between the provision for income taxes and the expected tax provision at the Swiss statutory income tax rate:
		Years Ended December 31
	(in millions of U.S. dollars)	2013			2012			2011
	Expected tax provision at Swiss statutory tax rate	$	331		$	233		$	160
	Permanent differences:
	Taxes on earnings subject to rate other than Swiss statutory rate	124			129			323
	Tax-exempt interest and dividends received deduction, net of proration	(27		)	(24		)	(21		)
	Net withholding taxes	27			23			19
	Favorable resolution of prior years' tax matters and closing statutes of limitations	(5		)	(124		)	—
	Change in valuation allowance	4			4			(2		)
	Other	26			29			23
	Total provision for income taxes	$	480		$	270		$	502
Schedule of the components of net deferred tax assets	'
	The following table presents the components of the net deferred tax assets:
		31-Dec			31-Dec
	(in millions of U.S. dollars)	2013			2012
	Deferred tax assets:
	Loss reserve discount	$	807		$	849
	Unearned premiums reserve	93			98
	Foreign tax credits	1,236			1,131
	Investments	3			43
	Provision for uncollectible balances	78			110
	Loss carry-forwards	54			55
	Other	184			110
	Total deferred tax assets	2,455			2,396
	Deferred tax liabilities:
	Deferred policy acquisition costs	138			68
	VOBA and other intangible assets	351			379
	Un-remitted foreign earnings	982			795
	Unrealized appreciation on investments	210			586
	Other	94			59
	Total deferred tax liabilities	1,775			1,887
	Valuation allowance	64			56
	Net deferred tax assets	$	616		$	453
Reconciliation schedule of unrecognized tax benefits	'
	The following table presents a reconciliation of the beginning and ending amount of gross unrecognized tax benefits:
		31-Dec			31-Dec
	(in millions of U.S. dollars)	2013			2012
	Balance, beginning of year	$	26		$	134
	Additions based on tax provisions related to the current year	5			19
	Reductions for settlements with tax authorities	—			(16		)
	Reductions for the lapse of the applicable statutes of limitations	(4		)	(111		)
	Balance, end of year	$	27		$	26

Debt_Tables

Debt (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Schedule of debt outstanding	'
		31-Dec		31-Dec
	(in millions of U.S. dollars)	2013		2012		Early Redemption Option
	Short-term debt
	ACE INA $500 million 5.875% senior notes due June 2014	$	500	$	—	Make-whole premium plus 0.20%
	Repurchase agreements (weighted average interest rate of 0.3% and 0.4%)	1,401		1,401		None
	Total short-term debt	$	1,901	$	1,401
	Long-term debt
	ACE INA senior notes:
	$500 million 5.875% due June 2014	$	—	$	500	Make-whole premium plus 0.20%
	$450 million 5.6% due May 2015	449		449		Make-whole premium plus 0.35%
	$700 million 2.6% due November 2015	700		699		Make-whole premium plus 0.20%
	$500 million 5.7% due February 2017	500		500		Make-whole premium plus 0.20%
	$300 million 5.8% due March 2018	300		300		Make-whole premium plus 0.35%
	$500 million 5.9% due June 2019	500		500		Make-whole premium plus 0.40%
	$475 million 2.7% due March 2023	473		—		Make-whole premium plus 0.10%
	$300 million 6.7% due May 2036	299		299		Make-whole premium plus 0.20%
	$475 million 4.15% due March 2043	474		—		Make-whole premium plus 0.15%
	ACE INA $100 million 8.875% debentures due August 2029	100		100		None
	Other long-term debt (2.75% to 7.1% due December 2019 to September 2020)	12		13		None
	Total long-term debt	$	3,807	$	3,360
	Trust preferred securities
	ACE INA capital securities due April 2030	$	309	$	309	Redemption price(1)

Commitments_contingencies_and_1

Commitments, contingencies, and guarantees (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Balance Sheet Locations, Fair Values In An Asset Or (Liability) Position, And Notional Values/Payment Provisions Of Derivative Instruments	'
	and notional values/payment provisions of our derivative instruments:
		31-Dec-13													31-Dec-12
		Consolidated		Fair Value								Notional		Consolidated	Fair Value					Notional
		Balance Sheet										Value/		Balance Sheet						Value/
		Location(1)		Derivative Asset				Derivative (Liability)				Payment		Location	Derivative Asset		Derivative (Liability)			Payment
	(in millions of U.S. dollars)											Provision								Provision
	Investment and embedded derivative instruments
	Foreign currency forward contracts	OA / (AP)		$	3			$	(4	)		$	1,202	AP	$	—	$	—		$	620
	Cross-currency swaps	OA / (AP)		—				—				50		AP	—		—			50
	Futures contracts on money market instruments	OA / (AP)		3				—				3,910		AP	1		—			2,710
	Futures contracts on notes and bonds	OA / (AP)		13				(2		)		871		AP	10		—			915
	Convertible bonds	FM AFS		302				—				254		FM AFS	309		—			279
				$	321			$	(6	)		$	6,287		$	320	$	—		$	4,574
	Other derivative instruments
	Futures contracts on equities(2)	OA / (AP)		$	—			$	(60	)		$	1,692	AP	$	—	$	(6	)	$	2,308
	Options on equity market indices(2)	OA / (AP)		6				—				250		AP	30		—			250
	Other	OA / (AP)		—				(2		)		8		AP	—		—			—
				$	6			$	(62	)		$	1,950		$	30	$	(6	)	$	2,558
	GLB(3)	(AP) / (FPB)		$	—			$	(427	)		$	277	AP / FPB	$	—	$	(1,352	)	$	1,100
	-1	Other assets (OA), Fixed maturities available for sale (FM AFS)
	(2)	Related to GMDB and GLB blocks of business.
	(3)	Includes both future policy benefits reserves and fair value derivative adjustment. Refer to Note 5 c) for additional information. Note that the payment provision related to GLB is the net amount at risk. The concept of a notional value does not apply to the GLB reinsurance contracts.
Net Realized Gains (Losses) Of Derivative Instrument Activity In Consolidated Statement Of Operations	'
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012				2011
	Investment and embedded derivative instruments
	Foreign currency forward contracts	$	11			$	(9	)		$	6
	All other futures contracts and options	61				(22		)		(98		)
	Convertible bonds	6				25				(50		)
	TBAs	—				—				(1		)
	Total investment and embedded derivative instruments	$	78			$	(6	)		$	(143	)
	GLB and other derivative instruments
	GLB(1)	$	878			$	171			$	(779	)
	Futures contracts on equities(2)	(555		)		(273		)		(12		)
	Options on equity market indices(2)	(24		)		(24		)		8
	Other	(2		)		(4		)		(4		)
	Total GLB and other derivative instruments	$	297			$	(130	)		$	(787	)
		$	375			$	(136	)		$	(930	)
	(1)	Excludes foreign exchange gains (losses) related to GLB.
	(2)	Related to GMDB and GLB blocks of business.
Schedule of Future Minimum Rental Payments for Operating Leases	'
	Future minimum lease payments under the leases are expected to be as follows:
	For the year ending December 31
	(in millions of U.S. dollars)
	2014	$	106
	2015	99
	2016	86
	2017	70
	2018	49
	Thereafter	124
	Total minimum future lease commitments	$	534

Shareholders_equity_Tables

Shareholders' equity (Tables)	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Note [Abstract]	'
Schedule of changes in Common Shares issued and outstanding	'
		Years Ended December 31
		2013		2012		2011
	Shares issued, beginning of year	342,832,412		342,832,412		341,094,559
	Exercise of stock options	—		—		1,737,853
	Shares issued, end of year	342,832,412		342,832,412		342,832,412
	Common Shares in treasury, end of year (at cost)	(3,038,477	)	(2,510,878	)	(5,905,136	)
	Shares issued and outstanding, end of year	339,793,935		340,321,534		336,927,276
	Common Shares issued to employee trust
	Balance, beginning of year	(9,467	)	(9,467	)	(101,481	)
	Shares redeemed	—		—		92,014
	Balance, end of year	(9,467	)	(9,467	)	(9,467	)

Sharebased_compensation_Tables

Share-based compensation (Tables)	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of pre-tax and after-tax share-based compensation expense	'
	The following table presents pre-tax and after-tax share-based compensation expense:
		Years Ended December 31
	(in millions of U.S. dollars)	2013				2012			2011
	Stock options and shares issued under ESPP:
	Pre-tax	$	24			$	22		$	23
	After-tax (1)	$	18			$	17		$	17
	Restricted stock:
	Pre-tax	$	153			$	109		$	108
	After-tax	$	89			$	64		$	70
Schedule of the weighted-average model valuation assumptions	'
		Years Ended December 31
		2013		2012		2011
	Dividend yield	2.4	%	2.7	%	2.2	%
	Expected volatility	27.8	%	29.8	%	28.8	%
	Risk-free interest rate	1	%	1.1	%	2.3	%
	Expected life	5.8 years		5.8 years		5.4 years
Rollforward of the company's stock options	'
	The following table presents a roll-forward of ACE's stock options:
	(Intrinsic Value in millions of U.S. dollars)	Number of Options			Weighted-Average Exercise Price			Weighted-Average Fair Value			Total Intrinsic Value
	Options outstanding, December 31, 2010	11,942,893			$	46.8
	Granted	1,649,824			$	62.68		$	14.67
	Exercised	(2,741,238	)		$	44.45					$	63
	Forfeited	(271,972	)		$	51.33
	Options outstanding, December 31, 2011	10,579,507			$	49.78
	Granted	1,462,103			$	73.36		$	15.58
	Exercised	(2,401,869	)		$	42.5					$	78
	Forfeited	(190,082	)		$	61.87
	Options outstanding, December 31, 2012	9,449,659			$	55.03
	Granted	1,821,063			$	85.41		$	17.29
	Exercised	(1,658,671	)		$	48.17					$	70
	Forfeited	(115,195	)		$	72.5
	Options outstanding, December 31, 2013	9,496,856			$	61.84					$	396
	Options exercisable, December 31, 2013	6,330,456			$	53.52					$	317
Rollforward of the company's restricted stock	'
	The following table presents a roll-forward of our restricted stock awards. Included in the roll-forward below are 20,969 restricted stock awards, 25,669 restricted stock awards, and 32,660 restricted stock awards that were granted to non-management directors during the years ended December 31, 2013, 2012, and 2011 respectively:
		Number of Restricted Stock			Weighted-Average Grant-Date Fair Value
	Unvested restricted stock, December 31, 2010	5,305,732			$	48.74
	Granted	1,808,745			$	60.01
	Vested	(1,929,189	)		$	50.82
	Forfeited	(333,798	)		$	47.46
	Unvested restricted stock, December 31, 2011	4,851,490			$	52.2
	Granted	1,589,178			$	73.46
	Vested	(1,923,385	)		$	52.71
	Forfeited	(262,436	)		$	58.4
	Unvested restricted stock, December 31, 2012	4,254,847			$	59.53
	Granted	1,544,485			$	86.07
	Vested	(1,951,494	)		$	57.44
	Forfeited	(139,651	)		$	67.72
	Unvested restricted stock, December 31, 2013	3,708,187			$	71.38

Pension_plans_Tables

Pension plans (Tables)	12 Months Ended
	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
Schedule of expected future benefit payments	'
	Expected future payments are as follows:
	For the year ending December 31
	(in millions of U.S dollars)
	2014	$	19
	2015	22
	2016	23
	2017	22
	2018	23
	2019-2023	129

Other_income_expense_Tables

Other (income) expense (Tables)	12 Months Ended
	Dec. 31, 2013
Other Income and Expenses [Abstract]	'
Schedule of the components of Other (income) expense	'
		Years Ended December 31
	(in millions of U.S. dollars)	2013			2012			2011
	Amortization of intangible assets	$	95		$	51		$	29
	Equity in net (income) loss of partially-owned entities	(119		)	(80		)	(32		)
	(Gains) losses from fair value changes in separate account assets	(16		)	(29		)	36
	Federal excise and capital taxes	24			22			20
	Acquisition-related costs	4			11			5
	Other	27			19			23
	Other (income) expense	$	15		$	(6	)	$	81

Segment_information_Tables

Segment information (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Operations By Segment	'
	For the Year Ended December 31, 2013 (in millions of U.S. dollars)	Insurance –			Insurance – North American Agriculture			Insurance –		Global			Life			Corporate			ACE
		North						Overseas		Reinsurance									Consolidated
		American P&C						General
	Net premiums written	$	5,915		$	1,627		$	6,520	$	991		$	1,972		$	—		$	17,025
	Net premiums earned	5,721			1,678			6,333		976			1,905			—			16,613
	Losses and loss expenses	3,776			1,524			3,062		396			582			8			9,348
	Policy benefits	—			—			—		—			515			—			515
	Policy acquisition costs	597			53			1,453		197			358			1			2,659
	Administrative expenses	601			11			1,008		50			343			198			2,211
	Underwriting income (loss)	747			90			810		333			107			(207		)	1,880
	Net investment income	1,021			26			539		280			251			27			2,144
	Net realized gains (losses) including OTTI	72			1			18		53			360			—			504
	Interest expense	5			1			5		5			15			244			275
	Other (income) expense:
	(Gains) losses from fair value changes in separate account assets	—			—			—		—			(16		)	—			(16		)
	Other	(58		)	32			39		(19		)	13			24			31
	Income tax expense (benefit)	347			20			222		36			34			(179		)	480
	Net income (loss)	$	1,546		$	64		$	1,101	$	644		$	672		$	(269	)	$	3,758
	For the Year Ended December 31, 2012	Insurance –			Insurance – North American Agriculture			Insurance –		Global			Life			Corporate			ACE
	(in millions of U.S. dollars)	North						Overseas		Reinsurance									Consolidated
		American P&C						General
	Net premiums written	$	5,349		$	1,859		$	5,863	$	1,025		$	1,979		$	—		$	16,075
	Net premiums earned	5,147			1,872			5,740		1,002			1,916			—			15,677
	Losses and loss expenses	3,715			1,911			2,862		553			611			1			9,653
	Policy benefits	—			—			—		—			521			—			521
	Policy acquisition costs	558			28			1,353		172			334			1			2,446
	Administrative expenses	608			(7		)	935		51			328			181			2,096
	Underwriting income (loss)	266			(60		)	590		226			122			(183		)	961
	Net investment income	1,066			25			521		290			251			28			2,181
	Net realized gains (losses) including OTTI	41			1			103		6			(72		)	(1		)	78
	Interest expense	12			—			5		4			12			217			250
	Other (income) expense:
	(Gains) losses from fair value changes in separate account assets	—			—			—		—			(29		)	—			(29		)
	Other	(41		)	32			3		(15		)	25			19			23
	Income tax expense (benefit)	229			(29		)	133		15			58			(136		)	270
	Net income (loss)	$	1,173		$	(37	)	$	1,073	$	518		$	235		$	(256	)	$	2,706
	For the Year Ended December 31, 2011	Insurance –			Insurance – North American Agriculture			Insurance –		Global			Life			Corporate			ACE
	(in millions of U.S. dollars)	North						Overseas		Reinsurance									Consolidated
		American P&C						General
	Net premiums written	$	4,900		$	1,951		$	5,629	$	979		$	1,913		$	—		$	15,372
	Net premiums earned	4,969			1,942			5,614		1,003			1,859			—			15,387
	Losses and loss expenses	3,577			1,699			3,029		621			593			1			9,520
	Policy benefits	—			—			—		—			401			—			401
	Policy acquisition costs	532			80			1,335		185			339			1			2,472
	Administrative expenses	598			(6		)	939		52			317			168			2,068
	Underwriting income (loss)	262			169			311		145			209			(170		)	926
	Net investment income	1,148			22			546		287			226			13			2,242
	Net realized gains (losses) including OTTI	28			6			33		(50		)	(806		)	(6		)	(795		)
	Interest expense	13			2			5		2			11			217			250
	Other (income) expense:
	(Gains) losses from fair value changes in separate account assets	—			—			—		—			36			—			36
	Other	(13		)	18			—		(1		)	26			15			45
	Income tax expense (benefit)	344			51			164		30			50			-137			502
	Net income (loss)	$	1,094		$	126		$	721	$	351		$	(494	)	$	(258	)	$	1,540
Net Premiums Earned For Segment By Product	'
	(in millions of U.S. dollars)	Property &			Casualty			Life,		ACE
		All Other						Accident &		Consolidated
	For the Year Ended December 31, 2013							Health
	Insurance – North American P&C	$	1,489		$	3,847		$	385	$	5,721
	Insurance – North American Agriculture	1,678			—			—		1,678
	Insurance – Overseas General	2,672			1,479			2,182		6,333
	Global Reinsurance	543			433			—		976
	Life	—			—			1,905		1,905
		$	6,382		$	5,759		$	4,472	$	16,613
	For the Year Ended December 31, 2012
	Insurance – North American P&C	$	1,370		$	3,406		$	371	$	5,147
	Insurance – North American Agriculture	1,872			—			—		1,872
	Insurance – Overseas General	2,236			1,379			2,125		5,740
	Global Reinsurance	495			507			—		1,002
	Life	—			—			1,916		1,916
		$	5,973		$	5,292		$	4,412	$	15,677
	For the Year Ended December 31, 2011
	Insurance – North American P&C	$	1,232		$	3,380		$	357	$	4,969
	Insurance – North American Agriculture	1,942			—			—		1,942
	Insurance – Overseas General	2,080			1,415			2,119		5,614
	Global Reinsurance	458			545			—		1,003
	Life	—			—			1,859		1,859
		$	5,712		$	5,340		$	4,335	$	15,387
Net Premiums Earned by Geographic Region	'Years Ended

Earnings_per_share_Tables

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Schedule Of Earnings Per Share, Basic And Diluted	'
		Years Ended December 31
	(in millions of U.S. dollars, except share and per share data)	2013		2012		2011
	Numerator:
	Net income	$	3,758	$	2,706	$	1,540
	Denominator:
	Denominator for basic earnings per share:
	Weighted-average shares outstanding	340,906,490		339,843,438		338,159,409
	Denominator for diluted earnings per share:
	Share-based compensation plans	3,241,085		2,903,512		2,620,815
	Weighted-average shares outstanding	344,147,575		342,746,950		340,780,224
	and assumed conversions
	Basic earnings per share	$	11.02	$	7.96	$	4.55
	Diluted earnings per share	$	10.92	$	7.89	$	4.52
	Potential anti-dilutive share conversions	1,031,297		896,591		111,326

Statutory_Financial_Informatio1

Statutory Financial Information (Tables)	12 Months Ended
	Dec. 31, 2013
Statutory Financial Information [Abstract]	'
Schedule of combined statutory capital and surplus and statutory net income (loss)	'
	he combined statutory capital and surplus was $25.6 billion and $24.4 billion at December 31, 2013 and 2012, respectively. The combined statutory net income was $3.7 billion, $2.9 billion, and $1.9 billion for the years ended December 31, 2013, 2012, and 2011, respectively.

Information_provided_in_connec1

Information provided in connection with outstanding debt of subsidiaries (Tables)	12 Months Ended
	Dec. 31, 2013
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Abstract]	'
Condensed Consolidating Balance Sheet	'
	Condensed Consolidating Balance Sheet at December 31, 2013
	(in millions of U.S. dollars)	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
		(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		Guarantor)			(Subsidiary			Subsidiaries
					Issuer)
	Assets
	Investments	$	32		$	10		$	60,886		$	—		$	60,928
	Cash(1)	—			16			748			(185		)	579
	Insurance and reinsurance balances receivable	—			—			5,835			(809		)	5,026
	Reinsurance recoverable on losses and loss expenses	—			—			20,057			(8,830		)	11,227
	Reinsurance recoverable on policy benefits	—			—			1,215			(997		)	218
	Value of business acquired	—			—			536			—			536
	Goodwill and other intangible assets	—			—			5,404			—			5,404
	Investments in subsidiaries	28,351			18,105			—			(46,456		)	—
	Due from subsidiaries and affiliates, net	844			—			—			(844		)	—
	Other assets	5			258			13,788			(3,459		)	10,592
	Total assets	$	29,232		$	18,389		$	108,469		$	(61,580	)	$	94,510
	Liabilities
	Unpaid losses and loss expenses	$	—		$	—		$	45,714		$	(8,271	)	$	37,443
	Unearned premiums	—			—			9,242			(1,703		)	7,539
	Future policy benefits	—			—			5,612			(997		)	4,615
	Due to (from) subsidiaries and affiliates, net	—			714			130			(844		)	—
	Affiliated notional cash pooling programs(1)	185			—			—			(185		)	—
	Short-term debt	—			500			1,401			—			1,901
	Long-term debt	—			3,795			12			—			3,807
	Trust preferred securities	—			309			—			—			309
	Other liabilities	222			1,318			11,655			(3,124		)	10,071
	Total liabilities	407			6,636			73,766			(15,124		)	65,685
	Total shareholders’ equity	28,825			11,753			34,703			(46,456		)	28,825
	Total liabilities and shareholders’ equity	$	29,232		$	18,389		$	108,469		$	(61,580	)	$	94,510
	(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Refer to Note 1f) for additional information. At December 31, 2013, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
	Condensed Consolidating Balance Sheet at December 31, 2012 (Revised)
	(in millions of U.S. dollars)	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
		(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		Guarantor)			(Subsidiary			Subsidiaries
					Issuer)
	Assets
	Investments	$	31		$	14		$	60,219		$	—		$	60,264
	Cash(1)	103			2			859			(349		)	615
	Insurance and reinsurance balances receivable	—			—			4,742			(595		)	4,147
	Reinsurance recoverable on losses and loss expenses	—			—			20,935			(8,857		)	12,078
	Reinsurance recoverable on policy benefits	—			—			1,229			(988		)	241
	Value of business acquired	—			—			614			—			614
	Goodwill and other intangible assets	—			—			4,975			—			4,975
	Investments in subsidiaries	27,251			17,016			—			(44,267		)	—
	Due from subsidiaries and affiliates, net	204			—			—			(204		)	—
	Other assets	13			210			11,304			(1,916		)	9,611
	Total assets	$	27,602		$	17,242		$	104,877		$	(57,176	)	$	92,545
	Liabilities
	Unpaid losses and loss expenses	$	—		$	—		$	46,109		$	(8,163	)	$	37,946
	Unearned premiums	—			—			8,248			(1,384		)	6,864
	Future policy benefits	—			—			5,458			(988		)	4,470
	Due to subsidiaries and affiliates, net	—			68			136			(204		)	—
	Affiliated notional cash pooling programs(1)	—			349			—			(349		)	—
	Short-term debt	—			—			1,401			—			1,401
	Long-term debt	—			3,347			13			—			3,360
	Trust preferred securities	—			309			—			—			309
	Other liabilities	71			1,195			11,219			(1,821		)	10,664
	Total liabilities	71			5,268			72,584			(12,909		)	65,014
	Total shareholders’ equity	27,531			11,974			32,293			(44,267		)	27,531
	Total liabilities and shareholders’ equity	$	27,602		$	17,242		$	104,877		$	(57,176	)	$	92,545
	(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Refer to Note 1f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
	Condensed Consolidating Balance Sheet at December 31, 2012 (As previously reported)
(in millions of U.S. dollars)	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments(2)			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries and
				Issuer)			Eliminations(1)
Assets
Investments	$	31		$	31,074		$	29,159		$	—		$	60,264
Cash(3)	103			515			(3		)	—			615
Insurance and reinsurance balances receivable	—			3,654			493			—			4,147
Reinsurance recoverable on losses and loss expenses	—			17,232			(5,154		)	—			12,078
Reinsurance recoverable on policy benefits	—			1,187			(946		)	—			241
Value of business acquired	—			610			4			—			614
Goodwill and other intangible assets	—			4,419			556			—			4,975
Investments in subsidiaries	27,251			—			—			(27,251		)	—
Due from subsidiaries and affiliates, net	204			—			—			(204		)	—
Other assets	13			7,563			2,035			—			9,611
Total assets	$	27,602		$	66,254		$	26,144		$	(27,455	)	$	92,545
Liabilities
Unpaid losses and loss expenses	$	—		$	31,356		$	6,590		$	—		$	37,946
Unearned premiums	—			5,872			992			—			6,864
Future policy benefits	—			3,876			594			—			4,470
Due to (from) subsidiaries and affiliates, net	—			384			(180		)	(204		)	—
Short-term debt	—			851			550			—			1,401
Long-term debt	—			3,360			—			—			3,360
Trust preferred securities	—			309			—			—			309
Other liabilities	71			8,272			2,321			—			10,664
Total liabilities	71			54,280			10,867			(204		)	65,014
Total shareholders’ equity	27,531			11,974			15,277			(27,251		)	27,531
Total liabilities and shareholders’ equity	$	27,602		$	66,254		$	26,144		$	(27,455	)	$	92,545
-1	Includes all other subsidiaries of ACE Limited and intercompany eliminations.
-2	Includes ACE Limited parent company eliminations.
-3	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Refer to Note 1f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condens
Condensed Consolidating Statement Of Operations and Comprehensive Income	'
	Condensed Consolidating Statements of Operations and Comprehensive Income
	For the Year Ended December 31, 2013	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
		(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		Guarantor)			(Subsidiary			Subsidiaries
	(in millions of U.S. dollars)				Issuer)
	Net premiums written	$	—		$	—		$	17,025		$	—		$	17,025
	Net premiums earned	—			—			16,613			—			16,613
	Net investment income	2			3			2,139			—			2,144
	Equity in earnings of subsidiaries	3,580			942			—			(4,522		)	—
	Net realized gains (losses) including OTTI	—			(2		)	506			—			504
	Losses and loss expenses	—			—			9,348			—			9,348
	Policy benefits	—			—			515			—			515
	Policy acquisition costs and administrative expenses	60			19			4,791			—			4,870
	Interest (income) expense	(32		)	270			37			—			275
	Other (income) expense	(221		)	27			209			—			15
	Income tax expense (benefit)	17			(108		)	571			—			480
	Net income	$	3,758		$	735		$	3,787		$	(4,522	)	$	3,758
	Comprehensive income	$	2,023		$	(230	)	$	2,051		$	(1,821	)	$	2,023
	Condensed Consolidating Statements of Operations and Comprehensive Income (Revised)
	For the Year Ended December 31, 2012	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
		(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		Guarantor)			(Subsidiary			Subsidiaries
	(in millions of U.S. dollars)				Issuer)
	Net premiums written	$	—		$	—		$	16,075		$	—		$	16,075
	Net premiums earned	—			—			15,677			—			15,677
	Net investment income	1			3			2,177			—			2,181
	Equity in earnings of subsidiaries	2,590			911			—			(3,501		)	—
	Net realized gains (losses) including OTTI	17			—			61			—			78
	Losses and loss expenses	—			—			9,653			—			9,653
	Policy benefits	—			—			521			—			521
	Policy acquisition costs and administrative expenses	62			28			4,452			—			4,542
	Interest (income) expense	(33		)	235			48			—			250
	Other (income) expense	(137		)	9			122			—			(6		)
	Income tax expense (benefit)	10			(110		)	370			—			270
	Net income	$	2,706		$	752		$	2,749		$	(3,501	)	$	2,706
	Comprehensive income	$	3,682		$	1,209		$	3,724		$	(4,933	)	$	3,682
	Condensed Consolidating Statements of Operations and Comprehensive Income (As previously reported)
	For the Year Ended December 31, 2012	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
		(Parent			Holdings Inc.			Limited			Adjustments (2)			Consolidated
		Guarantor)			(Subsidiary			Subsidiaries and
	(in millions of U.S. dollars)				Issuer)			Eliminations(1)
	Net premiums written	$	—		$	9,466		$	6,609		$	—		$	16,075
	Net premiums earned	—			9,194			6,483			—			15,677
	Net investment income	1			1,048			1,132			—			2,181
	Equity in earnings of subsidiaries	2,590			—			—			(2,590		)	—
	Net realized gains (losses) including OTTI	17			121			(60		)	—			78
	Losses and loss expenses	—			6,211			3,442			—			9,653
	Policy benefits	—			309			212			—			521
	Policy acquisition costs and administrative expenses	62			2,564			1,916			—			4,542
	Interest (income) expense	(33		)	257			26			—			250
	Other (income) expense	(137		)	77			54			—			(6		)
	Income tax expense	10			193			67			—			270
	Net income	$	2,706		$	752		$	1,838		$	(2,590	)	$	2,706
	Comprehensive income	$	3,682		$	1,209		$	1,381		$	(2,590	)	$	3,682
	-1	Includes all other subsidiaries of ACE Limited and intercompany eliminations.
	-2	Includes ACE Limited parent company eliminations.
	Condensed Consolidating Statements of Operations and Comprehensive Income (Revised)
	For the Year Ended December 31, 2011	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
		(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		Guarantor)			(Subsidiary			Subsidiaries
	(in millions of U.S. dollars)				Issuer)
	Net premiums written	$	—		$	—		$	15,372		$	—		$	15,372
	Net premiums earned	—			—			15,387			—			15,387
Net investment income	2			2			2,238			—			2,242
Equity in earnings of subsidiaries	1,459			989			—			(2,448		)	—
Net realized gains (losses) including OTTI	(4		)	—			(791		)	—			(795		)
Losses and loss expenses	—			—			9,520			—			9,520
Policy benefits	—			—			401			—			401
Policy acquisition costs and administrative expenses	69			37			4,434			—			4,540
Interest (income) expense	(37		)	266			21			—			250
Other (income) expense	(125		)	21			185			—			81
Income tax expense (benefit)	10			(103		)	595			—			502
Net income	$	1,540		$	770		$	1,678		$	(2,448	)	$	1,540
Comprehensive income	$	1,857		$	1,077		$	1,994		$	(3,071	)	$	1,857
Condensed Consolidating Statements of Operations and Comprehensive Income (As previously reported)
For the Year Ended December 31, 2011	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments (2)			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries and
(in millions of U.S. dollars)				Issuer)			Eliminations(1)
Net premiums written	$	—		$	9,081		$	6,291		$	—		$	15,372
Net premiums earned	—			9,082			6,305			—			15,387
Net investment income	2			1,096			1,144			—			2,242
Equity in earnings of subsidiaries	1,459			—			—			(1,459		)	—
Net realized gains (losses) including OTTI	(4		)	62			(853		)	—			(795		)
Losses and loss expenses	—			5,889			3,631			—			9,520
Policy benefits	—			192			209			—			401
Policy acquisition costs and administrative expenses	69			2,561			1,910			—			4,540
Interest (income) expense	(37		)	267			20			—			250
Other (income) expense	(125		)	143			63			—			81
Income tax expense	10			418			74			—			502
Net income	$	1,540		$	770		$	689		$	(1,459	)	$	1,540
Comprehensive income	$	1,857		$	1,077		$	382		$	(1,459	)	$	1,857
(1)	Includes all other subsidiaries of ACE Limited and intercompany eliminations.
(2)	Includes ACE Limited parent company eliminations.
Condensed Consolidating Statement of Cash Flows	'
	Condensed Consolidating Statement of Cash Flows
	For the Year Ended December 31, 2013	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
		(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		Guarantor)			(Subsidiary			Subsidiaries
	(in millions of U.S. dollars)				Issuer)
	Net cash flows from (used for) operating activities	$	970		$	(107	)	$	3,984		$	(825	)	$	4,022
	Cash flows from investing activities
	Purchases of fixed maturities available for sale	—			—			(21,504		)	106			(21,398		)
	Purchases of fixed maturities held to maturity	—			—			(447		)	—			(447		)
	Purchases of equity securities	—			—			(264		)	—			(264		)
	Sales of fixed maturities available for sale	—			—			10,519			(106		)	10,413
	Sales of equity securities	—			—			142			—			142
	Maturities and redemptions of fixed maturities available for sale	—			—			6,941			—			6,941
	Maturities and redemptions of fixed maturities held to maturity	—			—			1,488			—			1,488
	Net change in short-term investments	(1		)	4			521			—			524
	Net derivative instruments settlements	—			(1		)	(470		)	—			(471		)
	Acquisition of subsidiaries (net of cash acquired of $38)	—			—			(977		)	—			(977		)
	Capital contribution	(133		)	(1,097		)	—			1,230			—
	Other	—			(4		)	(389		)	—			(393		)
	Net cash flows used for investing activities	(134		)	(1,098		)	(4,440		)	1,230			(4,442		)
	Cash flows from financing activities
	Dividends paid on Common Shares	(517		)	—			—			—			(517		)
	Common Shares repurchased	—			—			(287		)	—			(287		)
	Net proceeds from issuance of long-term debt	—			947			—			—			947
	Proceeds from share-based compensation plans, including windfall tax benefits	14			—			121			—			135
	Advances (to) from affiliates	(621		)	621			—			—			—
	Dividends to parent company	—			—			(825		)	825			—
	Capital contribution	—			—			1,230			(1,230		)	—
	Net proceeds from (payments to) affiliated notional cash pooling programs(1)	185			(349		)	—			164			—
	Other	—			—			113			—			113
	Net cash flows (used for) from financing activities	(939		)	1,219			352			(241		)	391
	Effect of foreign currency rate changes on cash and cash equivalents	—			—			(7		)	—			(7		)
	Net (decrease) increase in cash	(103		)	14			(111		)	164			(36		)
	Cash – beginning of year(1)	103			2			859			(349		)	615
	Cash – end of year(1)	$	—		$	16		$	748		$	(185	)	$	579
	(1)	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2013 and December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
	Condensed Consolidating Statement of Cash Flows (Revised)
	For the Year Ended December 31, 2012	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
		(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		Guarantor)			(Subsidiary			Subsidiaries
	(in millions of U.S. dollars)				Issuer)
	Net cash flows from operating activities	$	573		$	296		$	3,876		$	(750	)	$	3,995
	Cash flows from investing activities
	Purchases of fixed maturities available for sale	—			—			(24,076		)	115			(23,961		)
	Purchases of fixed maturities held to maturity	—			—			(388		)	—			(388		)
	Purchases of equity securities	—			—			(135		)	—			(135		)
	Sales of fixed maturities available for sale	—			—			14,884			(115		)	14,769
	Sales of equity securities	—			—			119			—			119
	Maturities and redemptions of fixed maturities available for sale	—			—			5,523			—			5,523
	Maturities and redemptions of fixed maturities held to maturity	—			—			1,451			—			1,451
	Net change in short-term investments	—			(4		)	121			—			117
	Net derivative instruments settlements	(1		)	—			(280		)	—			(281		)
	Capital contribution	—			(352		)	(90		)	442			—
	Acquisition of subsidiaries (net of cash acquired of $8)	—			—			(98		)	—			(98		)
	Other	—			(33		)	(522		)	—			(555		)
	Net cash flows used for investing activities	(1		)	(389		)	(3,491		)	442			(3,439		)
	Cash flows from financing activities
	Dividends paid on Common Shares	(815		)	—			—			—			(815		)
	Common Shares repurchased	—			—			(11		)	—			(11		)
	Net proceeds from issuance of short-term debt	—			—			150			—			150
	Proceeds from share-based compensation plans, including windfall tax benefits	34			—			92			—			126
	Advances from (to) affiliates	206			(201		)	(5		)	—			—
	Dividends to parent company	—			—			(750		)	750			—
Capital contribution	—			90			352			(442		)	—
Net proceeds from affiliated notional cash pooling programs(1)	—			201			—			(201		)	—
Net cash flows (used for) from financing activities	(575		)	90			(172		)	107			(550		)
Effect of foreign currency rate changes on cash and cash equivalents	—			—			(5		)	—			(5		)
Net increase (decrease) in cash	(3		)	(3		)	208			(201		)	1
Cash – beginning of year(1)	106			5			651			(148		)	614
Cash – end of year(1)	$	103		$	2		$	859		$	(349	)	$	615
-1	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2012 and December 31, 2011, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condensed Consolidating Statement of Cash Flows (As previously reported)
For the Year Ended December 31, 2012	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments (2)			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries and
(in millions of U.S. dollars)				Issuer)			Eliminations(1)
Net cash flows from operating activities	$	781		$	1,744		$	1,920		$	(450	)	$	3,995
Cash flows from investing activities
Purchases of fixed maturities available for sale	—			(11,843		)	(12,001		)	—			(23,844		)
Purchases of fixed maturities held to maturity	—			(384		)	(4		)	—			(388		)
Purchases of equity securities	—			(70		)	(65		)	—			(135		)
Sales of fixed maturities available for sale	—			7,347			7,422			—			14,769
Sales of equity securities	—			59			60			—			119
Maturities and redemptions of fixed maturities available for sale	—			2,759			2,764			—			5,523
Maturities and redemptions of fixed maturities held to maturity	—			1,045			406			—			1,451
Net derivative instruments settlements	(1		)	(6		)	(274		)	—			(281		)
Capital contribution	—			—			(90		)	90			—
Advances from (to) affiliates	(2		)	—			—			2			—
Acquisition of subsidiaries (net of cash acquired of $8)	—			(111		)	13			—			(98		)
Other	—			(395		)	(160		)	—			(555		)
Net cash flows used for investing activities	(3		)	(1,599		)	(1,929		)	92			(3,439		)
Cash flows from financing activities
Dividends paid on Common Shares	(815		)	—			—			—			(815		)
Common Shares repurchased	—			—			(11		)	—			(11		)
Net proceeds from issuance of short-term debt	—			1			149			—			150
Proceeds from share-based compensation plans, including windfall tax benefits	34			13			79			—			126
Advances (to) from affiliates	—			(105		)	107			(2		)	—
Dividends to parent company	—			—			(450		)	450			—
Capital contribution	—			90			—			(90		)	—
Net cash flows used for financing activities	(781		)	(1		)	(126		)	358			(550		)
Effect of foreign currency rate changes on cash and cash equivalents	—			(11		)	6			—			(5		)
Net increase (decrease) in cash	(3		)	133			(129		)	—			1
Cash – beginning of year	106			382			126			—			614
Cash – end of year(3)	$	103		$	515		$	(3	)	$	—		$	615
(1)	Includes all other subsidiaries of ACE Limited and intercompany eliminations.
(2)	Includes ACE Limited parent company eliminations and certain consolidating adjustments.
(3)	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condensed Consolidating Statement of Cash Flows (Revised)
For the Year Ended December 31, 2011	ACE Limited			ACE INA			Other ACE			Consolidating			ACE Limited
	(Parent			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
	Guarantor)			(Subsidiary			Subsidiaries
(in millions of U.S. dollars)				Issuer)
Net cash flows from operating activities	$	831		$	1,221		$	3,455		$	(2,037	)	$	3,470
Cash flows from investing activities
Purchases of fixed maturities available for sale	—			—			(24,601		)	323			(24,278		)
Purchases of fixed maturities held to maturity	—			—			(340		)	—			(340		)
Purchases of equity securities	—			—			(309		)	—			(309		)
Sales of fixed maturities available for sale	—			—			18,294			(323		)	17,971
Sales of equity securities	—			—			376			—			376
Maturities and redemptions of fixed maturities available for sale	—			—			3,720			—			3,720
Maturities and redemptions of fixed maturities held to maturity	—			—			1,279			—			1,279
Net change in short-term investments	9			—			(309		)	—			(300		)
Net derivative instruments settlements	(3		)	—			(64		)	—			(67		)
Capital contribution	(385		)	(581		)	—			966			—
Acquisition of subsidiaries (net of cash acquired of $91)	—			(76		)	(530		)	—			(606		)
Other	—			(19		)	(463		)	—			(482		)
Net cash flows used for investing activities	(379		)	(676		)	(2,947		)	966			(3,036		)
Cash flows from financing activities
Dividends paid on Common Shares	(459		)	—			—			—			(459		)
Common Shares repurchased	—			—			(195		)	—			(195		)
Net proceeds from issuance (repayments) of short-term debt	(300		)	—			250			—			(50		)
Proceeds from share-based compensation plans, including windfall tax benefits	133			—			6			—			139
Advances from (to) affiliates	(28		)	(721		)	749			—			—
Dividends to parent company	—			—			(2,037		)	2,037			—
Capital contribution	—			—			966			(966		)	—
Net proceeds from affiliated notional cash pooling programs(1)	—			148			—			(148		)	—
Net cash flows used for financing activities	(654		)	(573		)	(261		)	923			(565		)
Effect of foreign currency rate changes on cash and cash equivalents	—			—			(27		)	—			(27		)
Net increase (decrease) in cash	(202		)	(28		)	220			(148		)	(158		)
Cash – beginning of year(1)	308			33			431			—			772
Cash – end of year(1)	$	106		$	5		$	651		$	(148	)	$	614

Condensed_Unaudited_Quarterly_1

Condensed Unaudited Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Schedule of quarterly financial information	'
		Three Months Ended
		31-Mar		30-Jun			30-Sep			31-Dec
	(in millions of U.S. dollars, except per share data)	2013		2013			2013			2013
	Net premiums earned	$	3,573	$	4,067		$	4,610		$	4,363
	Net investment income	531		534			522			557
	Net realized gains (losses) including OTTI	206		104			40			154		(1)
	Total revenues	$	4,310	$	4,705		$	5,172		$	5,074
	Losses and loss expenses	$	1,926	$	2,250		$	2,655		$	2,517
	Policy benefits	$	131	$	110		$	138		$	136
	Net income	$	953	$	891		$	916		$	998
	Basic earnings per share	$	2.8	$	2.61		$	2.68		$	2.93
	Diluted earnings per share	$	2.77	$	2.59		$	2.66		$	2.9
	(1)	Includes a realized gain of $92 million for an out-of-period adjustment related to guaranteed living benefits. Refer to Note 4 a) for additional information.
		Three Months Ended
		31-Mar		30-Jun			30-Sep			31-Dec
	(in millions of U.S. dollars, except per share data)	2012		2012			2012			2012
	Net premiums earned	$	3,381	$	3,783		$	4,665		$	3,848
	Net investment income	544		537			533			567
	Net realized gains (losses) including OTTI	260		(394		)	(60		)	272
	Total revenues	$	4,185	$	3,926		$	5,138		$	4,687
	Losses and loss expenses	$	1,804	$	2,119		$	3,047		$	2,683
	Policy benefits	$	147	$	102		$	130		$	142
	Net income	$	973	$	328		$	640		$	765
	Basic earnings per share	$	2.87	$	0.96		$	1.88		$	2.24
	Diluted earnings per share	$	2.84	$	0.96		$	1.86		$	2.22

Summary_of_significant_account2

Summary of significant accounting policies (Narrative) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary of significant accounting policies [Line Items]	'	'	'
Deferred Marketing Costs, Amortization Period	'10 years	'	'
Deferred marketing costs reported in Deferred policy acquisition costs	$307	$274	'
Amortization expense for deferred marketing costs	128	119	128
Recoverable from unrated reinsurers, ceded reserve, default factor (percent)	34.00%	'	'
Reinsurance business assumed	27	32	'
Percentage of fair value of loaned securities	102.00%	'	'
Maximum overdraft balance guaranteed by ACE Ltd	300	'	'
Quality assessment threshold used in goodwill impairment testing	50.00%	'	'
Supplemental Information for Property, Casualty Insurance Underwriters, Reserves for Unpaid Claims and Claims Adjustment Expense	26,831	26,547	25,875
Gross liability for the amounts due to claimants	631	'	'
Reinsurance recoverables for amounts due from life insurance companies	577	'	'
Deposit assets reflected in Other assets	100	138	'
Reinsurance deposit liabilities included in Deposit liabilities	131	283	'
Contract holder deposit funds included in Deposit liabilities	699	548	'
Net operating results of ESIS included within Administrative expenses	25	23	21
Structured settlements	'	'	'
Summary of significant accounting policies [Line Items]	'	'	'
Loss and loss expenses reserves, net of discount	$54	$58	'
Minimum	'	'	'
Summary of significant accounting policies [Line Items]	'	'	'
Amortization period for value of reinsurance business assumed	'9 years	'	'
Finite-lived intangible asset useful life	'1 year	'	'
Interest rates used in calculating reserves	1.00%	1.00%	'
Reinsurance Premiums, Amortization Period	'1 year	'	'
Maximum	'	'	'
Summary of significant accounting policies [Line Items]	'	'	'
Amortization period for value of reinsurance business assumed	'40 years	'	'
Finite-lived intangible asset useful life	'20 years	'	'
Interest rates used in calculating reserves	6.50%	4.50%	'
Reinsurance Premiums, Amortization Period	'3 years	'	'

Acquisitions_Detail

Acquisitions (Detail) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Sep. 18, 2012

Apr. 02, 2013

8-May-13

2-May-13

Apr. 01, 2011

Feb. 02, 2011

Nov. 30, 2011

Dec. 28, 2011

Jan. 12, 2014

Jan. 03, 2013

Jan. 12, 2014

In Millions, unless otherwise specified

PT Asuransi Jaya Proteksi (JaPro)

Fianzas Monterrey

ABA Seguros

ABA Seguros

New York Life's Korea and Hong Kong

New York Life's Korea and Hong Kong

Penn Millers Holding Corporation

Rio Guayas

The Siam Commercial Sammagi Insurance PCL (Samaggi)

Subsequent Event [Member]

Subsequent Event [Member]

PT Asuransi Jaya Proteksi (JaPro)

The Siam Commercial Sammagi Insurance PCL (Samaggi)

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of business acquired

'

'

'

80.00%

'

'

'

'

'

'

'

60.90%

20.00%

'

Expected cash consideration for acquisition

'

'

'

'

'

'

'

'

'

'

'

'

'

$185

Business Combination, Consideration Transferred

'

'

'

107

'

690

'

450

'

107

65

'

'

'

Goodwill generated in acquisitions

4,603

4,319

4,148

'

135

'

283

'

91

'

'

'

'

'

Other intangible assets generated in acquisition

'

'

'

'

73

'

140

'

163

'

'

'

'

'

Additional investment percentage to be acquired after tender offer

'

'

'

'

'

'

'

'

'

'

'

'

'

39.10%

Business Acquisition, Goodwill, Expected Tax Deductible Amount

'

'

'

'

$0

'

$0

'

$0

'

'

'

'

'

Investments_Narrative_Detail

Investments (Narrative) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	partnerships
	Security
Investments, Debt and Equity Securities [Abstract]	'	'	'
Net unrealized appreciation (depreciation) included in OCI	$25,000,000	$137,000,000	'
Net unrealized depreciation included in AOCI	-4,000,000	-25,000,000	'
Percentage of mortgage-backed securities represented by investments in US government agency bonds	83.00%	85.00%	'
Portion of gross unrealized loss represented by the United States Treasury and Agency obligations	425,000,000	'	'
Company assumed recovery rate	32.00%	'	'
Moodys historical mean recovery rate	42.00%	'	'
Credit losses recognized in net income for corporate securities	11,000,000	14,000,000	9,000,000
Credit losses recognized in net income for mortgage-backed securities	1,000,000	6,000,000	11,000,000
Limited partnerships number	62	'	'
Trading securities - mutual funds	246,000,000	212,000,000	'
Trading securities - equity securities	23,000,000	23,000,000	'
Trading securities - fixed maturities	7,000,000	8,000,000	'
Number of fixed maturities in an unrealized loss position	6,161	'	'
Total number of fixed maturities	25,062	'	'
Largest single unrealized loss in the fixed maturities	-6,000,000	'	'
Number of equity securities in an unrealized loss position	71	'	'
Total number of equity securities	185	'	'
Largest single unrealized loss in the equity securities	-58,000,000	'	'
Restricted assets in fixed maturities and short-term investments	16,300,000,000	16,600,000,000	'
Restricted assets in cash	$162,000,000	$139,000,000	'

Investments_Schedule_Of_Amorti

Investments (Schedule Of Amortized Cost And Fair Value Of Fixed Maturities And Related Other-Than-Temporary Impairment Recognized In Accumulated Other Comprehensive Income) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Investment [Line Items]	'	'
Available for sale, Amortized Cost	$48,406	$44,666
Available for sale, Gross Unrealized Appreciation	1,465	2,725
Available for sale, Gross Unrealized Depreciation	-617	-85
Available for sale, Fair Value	49,254	47,306
Available for sale, OTTI recognized in AOCI	-40	-91
Held to maturity, Amortized Cost	6,098	7,270
Held to maturity, Gross Unrealized Appreciation	187	367
Held to maturity, Gross Unrealized Depreciation	-22	-4
Held to maturity, Fair Value	6,263	7,633
Held to maturity, OTTI recognized in AOCI	'	'
U.S. Treasury and agency	'	'
Investment [Line Items]	'	'
Available for sale, Amortized Cost	2,946	3,553
Available for sale, Gross Unrealized Appreciation	62	183
Available for sale, Gross Unrealized Depreciation	-59	-1
Available for sale, Fair Value	2,949	3,735
Available for sale, OTTI recognized in AOCI	0	0
Held to maturity, Amortized Cost	820	1,044
Held to maturity, Gross Unrealized Appreciation	16	39
Held to maturity, Gross Unrealized Depreciation	-4	0
Held to maturity, Fair Value	832	1,083
Held to maturity, OTTI recognized in AOCI	0	0
Foreign	'	'
Investment [Line Items]	'	'
Available for sale, Amortized Cost	14,336	13,016
Available for sale, Gross Unrealized Appreciation	377	711
Available for sale, Gross Unrealized Depreciation	-122	-14
Available for sale, Fair Value	14,591	13,713
Available for sale, OTTI recognized in AOCI	0	0
Held to maturity, Amortized Cost	864	910
Held to maturity, Gross Unrealized Appreciation	33	54
Held to maturity, Gross Unrealized Depreciation	0	0
Held to maturity, Fair Value	897	964
Held to maturity, OTTI recognized in AOCI	0	0
Corporate securities	'	'
Investment [Line Items]	'	'
Available for sale, Amortized Cost	16,825	15,529
Available for sale, Gross Unrealized Appreciation	777	1,210
Available for sale, Gross Unrealized Depreciation	-132	-31
Available for sale, Fair Value	17,470	16,708
Available for sale, OTTI recognized in AOCI	-6	-7
Held to maturity, Amortized Cost	1,922	2,133
Held to maturity, Gross Unrealized Appreciation	83	142
Held to maturity, Gross Unrealized Depreciation	0	0
Held to maturity, Fair Value	2,005	2,275
Held to maturity, OTTI recognized in AOCI	0	0
Mortgage backed-securities	'	'
Investment [Line Items]	'	'
Available for sale, Amortized Cost	10,937	10,051
Available for sale, Gross Unrealized Appreciation	184	458
Available for sale, Gross Unrealized Depreciation	-227	-36
Available for sale, Fair Value	10,894	10,473
Available for sale, OTTI recognized in AOCI	-34	-84
Held to maturity, Amortized Cost	1,341	2,028
Held to maturity, Gross Unrealized Appreciation	39	88
Held to maturity, Gross Unrealized Depreciation	-1	0
Held to maturity, Fair Value	1,379	2,116
Held to maturity, OTTI recognized in AOCI	0	0
States, municipalities, and political subdivisions	'	'
Investment [Line Items]	'	'
Available for sale, Amortized Cost	3,362	2,517
Available for sale, Gross Unrealized Appreciation	65	163
Available for sale, Gross Unrealized Depreciation	-77	-3
Available for sale, Fair Value	3,350	2,677
Available for sale, OTTI recognized in AOCI	0	0
Held to maturity, Amortized Cost	1,151	1,155
Held to maturity, Gross Unrealized Appreciation	16	44
Held to maturity, Gross Unrealized Depreciation	-17	-4
Held to maturity, Fair Value	1,150	1,195
Held to maturity, OTTI recognized in AOCI	$0	$0

Investments_Schedule_Of_Fixed_

Investments (Schedule Of Fixed Maturities By Contractual Maturity) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]	'	'
Available for sale, Due in 1 year or less, Amortized Cost	$2,387	$1,887
Available for sale, Due after 1 year through 5 years, Amortized Cost	14,139	13,411
Available for sale, Due after 5 years though 10 years, Amortized Cost	16,200	15,032
Available for sale, Due after 10 years, Amortized Cost	4,743	4,285
Available for sale, Subtotal, Amortized Cost	37,469	34,615
Available for sale, Mortgage-backed securities, Amortized Cost	10,937	10,051
Available for sale, Amortized Cost	48,406	44,666
Available for sale, Due in 1 year or less, Fair Value	2,411	1,906
Available for sale, Due after 1 year through 5 years, Fair Value	14,602	14,010
Available for sale, Due after 5 years through 10 years, Fair Value	16,535	16,153
Available for sale, Due after 10 years, Fair Value	4,812	4,764
Available for sale, Subtotal, Fair Value	38,360	36,833
Available for sale, Mortgage backed securities, Fair Value	10,894	10,473
Available for sale, Fair Value	49,254	47,306
Held to maturity, Due in 1 year or less, Amortized Cost	401	656
Held to maturity, Due after 1 year through 5 years, Amortized Cost	2,284	1,870
Held to maturity, Due after 5 years through 10 years, Amortized Cost	1,686	2,119
Held to maturity, Due after 10 years, Amortized Cost	386	597
Held to maturity, Subtotal, Amortized Cost	4,757	5,242
Held to maturity, Mortgage backed securities, Amortized Cost	1,341	2,028
Held-to-maturity Securities	6,098	7,270
Held to maturity, Due in 1 year or less, Fair Value	405	659
Held to maturity, Due after 1 year through 5, Fair Value	2,363	1,950
Held to maturity, Due after 5 years through 10 years, Fair Value	1,723	2,267
Held to maturity, Due after 10 years, Fair Value	393	641
Held to maturity, Subtotal, Fair Value	4,884	5,517
Held to maturity, Mortgage backed securities, Fair Value	1,379	2,116
Held to maturity, Fair Value	$6,263	$7,633

Investments_Schedule_Of_Cost_A

Investments (Schedule Of Cost And Fair Value Of Equity Securities) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]	'	'
Cost	$841	$707
Gross unrealized appreciation	63	41
Gross unrealized depreciation	-67	-4
Fair value	$837	$744

Investments_Schedule_Of_Defaul

Investments (Schedule Of Default Assumptions By Moody's Rating Categories) (Details)	12 Months Ended
	Dec. 31, 2013
Investment Grade | Aaa - Bbb | Minimum	'
Financing Receivable, Recorded Investment [Line Items]	'
1-in-100 Year Default Rate	0.00%
Historical Mean Default Rate	0.00%
Investment Grade | Aaa - Bbb | Maximum	'
Financing Receivable, Recorded Investment [Line Items]	'
1-in-100 Year Default Rate	1.40%
Historical Mean Default Rate	0.30%
Below Investment Grade | Ba	'
Financing Receivable, Recorded Investment [Line Items]	'
1-in-100 Year Default Rate	4.90%
Historical Mean Default Rate	1.10%
Below Investment Grade | B	'
Financing Receivable, Recorded Investment [Line Items]	'
1-in-100 Year Default Rate	12.80%
Historical Mean Default Rate	3.40%
Below Investment Grade | Caa - C	'
Financing Receivable, Recorded Investment [Line Items]	'
1-in-100 Year Default Rate	53.20%
Historical Mean Default Rate	13.80%

Investments_Net_Realized_Gains

Investments (Net Realized Gains (Losses) And Losses Included In Net Realized Gains (Losses) And Other Comprehensive Income) (Detail) (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
Investments, Debt and Equity Securities [Abstract]	'	'	'	'	'	'	'	'	'	'	'
OTTI on fixed maturities, gross	'	'	'	'	'	'	'	'	($18)	($26)	($61)
OTTI on fixed maturities recognized in OCI (pre-tax)	'	'	'	'	'	'	'	'	0	1	15
OTTI on fixed maturities, net	'	'	'	'	'	'	'	'	-18	-25	-46
Fixed maturities, Gross realized gains excluding OTTI	'	'	'	'	'	'	'	'	237	388	410
Fixed maturities, Gross realized losses excluding OTTI	'	'	'	'	'	'	'	'	-129	-133	-200
Total fixed maturities	'	'	'	'	'	'	'	'	90	230	164
OTTI on equity securities	'	'	'	'	'	'	'	'	-2	-5	-1
Equity securities, Gross realized gains excluding OTTI	'	'	'	'	'	'	'	'	21	11	15
Equity securities, Gross realized losses excluding OTTI	'	'	'	'	'	'	'	'	-4	-2	-5
Total equity securities	'	'	'	'	'	'	'	'	15	4	9
OTTI on other investments	'	'	'	'	'	'	'	'	-2	-7	-3
Foreign exchange losses	'	'	'	'	'	'	'	'	29	-16	-13
Investment and embedded derivative instruments	'	'	'	'	'	'	'	'	78	-6	-143
Fair value adjustments on insurance derivative	'	'	'	'	'	'	'	'	878	171	-779
S&P put options and futures	'	'	'	'	'	'	'	'	-579	-297	-4
Other derivative instruments	'	'	'	'	'	'	'	'	-2	-4	-4
Other	'	'	'	'	'	'	'	'	-3	3	-22
Total net realized gains (losses)	154	40	104	206	272	-60	-394	260	504	78	-795
Change in net unrealized appreciation (depreciation) on investments, Fixed maturities available for sale	'	'	'	'	'	'	'	'	-1,798	1,099	569
Change in net unrealized appreciation (depreciation) on investments, Fixed maturities held to maturity	'	'	'	'	'	'	'	'	-82	-94	-89
Change in net unrealized appreciation (depreciation) on investments, Equity securities	'	'	'	'	'	'	'	'	-41	61	-47
Change in net unrealized appreciation (depreciation) on investments, Other	'	'	'	'	'	'	'	'	54	50	40
Change in net unrealized appreciation (depreciation) on investments, Income tax expense	'	'	'	'	'	'	'	'	408	-198	-157
Change in net unrealized appreciation on investments,	'	'	'	'	'	'	'	'	-1,459	918	316
Total net realized gains (losses) and change in net unrealized appreciation (depreciation) on investments	'	'	'	'	'	'	'	'	($955)	$996	($479)

Investments_RollForward_Of_Pre

Investments (Roll-Forward Of Pre-Tax Credit Losses Related To Fixed Maturities For Which Portion Of Other-Than-Temporary Impairment Was Recognized In Other Comprehensive Income) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Roll-Forward Of Pre-Tax Credit Losses Related To Fixed Maturities For Which Portion Of OTTI Was Recognized In OCI	'	'	'
Balance of credit losses related to securities still held-beginning of period	$43	$74	$137
Additions where no OTTI was previously recorded	9	8	12
Additions where an OTTI was previously recorded	3	12	8
Reductions for securities sold during the period	-18	-51	-83
Balance of credit losses related to securities still held-end of period	$37	$43	$74

Investments_Schedule_Of_Other_

Investments (Schedule Of Other Investments) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Schedule of Cost-method Investments [Line Items]	'	'
Other investments - Total at Fair Value	$2,976	$2,716
Other investments - Total at Cost	2,671	2,465
Fair Value	'	'
Schedule of Cost-method Investments [Line Items]	'	'
Investment funds	428	395
Limited partnerships	576	531
Partially owned investment companies	1,284	1,186
Life insurance policies	180	148
Policy loans	179	164
Trading securities	276	243
Other	53	49
Other investments - Total at Fair Value	2,976	2,716
Cost	'	'
Schedule of Cost-method Investments [Line Items]	'	'
Investment funds	278	278
Limited partnerships	424	398
Partially owned investment companies	1,284	1,187
Life insurance policies	180	148
Policy loans	179	164
Trading securities	273	242
Other	53	48
Other investments - Total at Cost	$2,671	$2,465

Investments_Schedule_Of_Invest

Investments (Schedule Of Investments In Partially-Owned Insurance Companies) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Investment [Line Items]	'	'
Carrying Value	$470	$454
Issued Share Capital	1,046	715
Freisenbruch-Meyer | Bermuda	'	'
Investment [Line Items]	'	'
Carrying Value	9	9
Issued Share Capital	5	5
Ownership Percentage	40.00%	40.00%
ACE Cooperative Ins. Co. - Saudi Arabia | Saudi Arabia	'	'
Investment [Line Items]	'	'
Carrying Value	10	9
Issued Share Capital	27	27
Ownership Percentage	30.00%	30.00%
Huatai Group | China	'	'
Investment [Line Items]	'	'
Carrying Value	365	350
Issued Share Capital	631	474
Ownership Percentage	20.00%	20.00%
Huatai Life Insurance Company | China	'	'
Investment [Line Items]	'	'
Carrying Value	84	84
Issued Share Capital	379	205
Ownership Percentage	20.00%	20.00%
Russian Reinsurance Company | Russia	'	'
Investment [Line Items]	'	'
Carrying Value	2	2
Issued Share Capital	$4	$4
Ownership Percentage	23.30%	23.30%

Investments_Aggregate_Fair_Val

Investments (Aggregate Fair Value And Gross Unrealized Loss By Length Of Time Security Has Continuously Been In Unrealized Loss Position) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Investment [Line Items]	'	'
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	$18,228	$3,968
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-652	-48
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	894	577
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-63	-50
Investment securities, Unrealized loss position, Total Fair Value	19,122	4,545
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-715	-98
U.S. Treasury and agency	'	'
Investment [Line Items]	'	'
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	1,794	440
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-57	-1
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	31	0
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-6	0
Investment securities, Unrealized loss position, Total Fair Value	1,825	440
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-63	-1
Foreign	'	'
Investment [Line Items]	'	'
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	4,621	1,234
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-114	-8
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	201	88
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-8	-6
Investment securities, Unrealized loss position, Total Fair Value	4,822	1,322
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-122	-14
Corporate securities	'	'
Investment [Line Items]	'	'
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	3,836	1,026
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-118	-23
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	194	85
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-14	-8
Investment securities, Unrealized loss position, Total Fair Value	4,030	1,111
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-132	-31
Mortgage backed-securities	'	'
Investment [Line Items]	'	'
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	5,248	855
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-197	-4
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	384	356
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-31	-32
Investment securities, Unrealized loss position, Total Fair Value	5,632	1,211
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-228	-36
States, municipalities, and political subdivisions	'	'
Investment [Line Items]	'	'
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	2,164	316
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-90	-3
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	84	48
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-4	-4
Investment securities, Unrealized loss position, Total Fair Value	2,248	364
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-94	-7
Total fixed maturities	'	'
Investment [Line Items]	'	'
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	17,663	3,871
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-576	-39
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	894	577
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-63	-50
Investment securities, Unrealized loss position, Total Fair Value	18,557	4,448
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-639	-89
Equity securities	'	'
Investment [Line Items]	'	'
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	498	29
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-67	-4
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	0	'
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	0	'
Investment securities, Unrealized loss position, Total Fair Value	498	29
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-67	-4
Other investments	'	'
Investment [Line Items]	'	'
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	67	68
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-9	-5
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	0	'
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	0	'
Investment securities, Unrealized loss position, Total Fair Value	67	68
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	($9)	($5)

Investments_Schedule_Of_Source

Investments (Schedule Of Sources Of 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	$2,264	$2,300	$2,337
Investment expenses	-120	-119	-95
Net investment income	2,144	2,181	2,242
Fixed Maturities [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Gross investment income	2,093	2,134	2,196
Short-term investments	'	'	'
Net Investment Income [Line Items]	'	'	'
Gross investment income	29	28	43
Equity securities	'	'	'
Net Investment Income [Line Items]	'	'	'
Gross investment income	37	34	36
Other Investments [Member]	'	'	'
Net Investment Income [Line Items]	'	'	'
Gross investment income	$105	$104	$62

Investments_Schedule_Of_Compon

Investments (Schedule Of Components Of Restricted Assets) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]	'	'
Trust funds	$11,315	$11,389
Deposits with non-U.S. regulatory authorities	1,970	2,133
Assets pledged under reverse repurchase agreements	1,435	1,401
Deposits with U.S. regulatory authorities	1,334	1,338
Other pledged assets	391	456
Total restricted assets	$16,445	$16,717

Fair_Value_Measurements_Narrat

Fair Value Measurements (Narrative) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	Year
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
GLB - Lapse rate - lower range	1.00%	'	'
GLB - Lapse rate - upper range	6.00%	'	'
GLB - Spike lapse rate - lower range	10.00%	'	'
GLB - Spike lapse rate - upper range	30.00%	'	'
GLB - Ultimate lapse rate	10.00%	'	'
GLB - Length of ultimate lapse rate period, years	2	'	'
GLB - Adjustment factor for valuable guarantees - lower	8.00%	'	'
GLB - Adjustment factor for valuable guarantees - upper	68.00%	'	'
Percent of GMIB guaranteed value that are represented by clients with several years of annuitization experience	37.00%	'	'
Guaranteed Living Benefits, Net Income Impact From Model Refinement	$9,000,000	$49,000,000	$14,000,000
Level 1 To Level 2 Transfers	19,000,000	40,000,000	'
Level 2 To Level 1 Transfers	'	$15,000,000	'
First year only [Domain]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
GLB - Lapse rate - lower range	7.00%	'	'
Redemption Notice Periods Lower Range [Member]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
Notice period for redemption for alternative investments investment funds, days	'5 days	'	'
Redemption Notice Periods Upper Range [Member]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
Notice period for redemption for alternative investments investment funds, days	'120 days	'	'
Minimum | First year only [Domain]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
GLB - First year maximum annuitization rate	7.00%	'	'
Minimum | First year and subsequent years [Domain]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
GLB - First year maximum annuitization rate	14.00%	'	'
Maximum | First year only [Domain]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
GLB - First year maximum annuitization rate	12.00%	'	'
Maximum | First year and subsequent years [Domain]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
GLB - First year maximum annuitization rate	55.00%	'	'
GLB - Weighted average maximum annuitization rate - rate 1	7.00%	'	'
GLB - Weighted average maximum annuitization rate - rate 2	15.00%	'	'
GLB - Weighted average maximum annuitization rate - rate 3	30.00%	'	'

Fair_Value_Measurements_Financ

Fair Value Measurements (Financial Instruments Measured At Fair Value On Recurring Basis) (Detail) (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	$49,254		$47,306
Equity securities	837		744
Short-term investments	1,763		2,228
Other investments	2,976		2,716
Securities lending collateral	1,632		1,791
Level 1	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	1,849		2,292
Equity securities	373		253
Short-term investments	953		1,503
Other investments	305		268
Securities lending collateral	'		'
Investment derivative instruments, assets	19		11
Other derivative instruments, assets	'		-6
Separate account assets	1,145		872
Total assets measured at fair value	4,644		5,193
Investment derivative instruments, liability	6		'
Other derivative instruments, liability	60		'
GLB	'	[1]	'	[1]
Total liabilities measured at fair value	66		'
Level 1 | U.S. Treasury and agency	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	1,626		2,050
Level 1 | Foreign	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	223		222
Level 1 | Corporate securities	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	'		20
Level 1 | Mortgage backed-securities	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	'		'
Level 1 | States, municipalities, and political subdivisions	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	'		'
Level 2	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	47,187		44,839
Equity securities	460		488
Short-term investments	803		725
Other investments	231		196
Securities lending collateral	1,632		1,791
Investment derivative instruments, assets	'		'
Other derivative instruments, assets	6		30
Separate account assets	81		71
Total assets measured at fair value	50,400		48,140
Investment derivative instruments, liability	'		'
Other derivative instruments, liability	2		'
GLB	'	[1]	'	[1]
Total liabilities measured at fair value	2		'
Level 2 | U.S. Treasury and agency	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	1,323		1,685
Level 2 | Foreign	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	14,324		13,431
Level 2 | Corporate securities	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	17,304		16,586
Level 2 | Mortgage backed-securities	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	10,886		10,460
Level 2 | States, municipalities, and political subdivisions	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	3,350		2,677
Level 3	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	218		175
Equity securities	4		3
Short-term investments	7		'
Other investments	2,440		2,252
Securities lending collateral	'		'
Investment derivative instruments, assets	'		'
Other derivative instruments, assets	'		'
Separate account assets	'		'
Total assets measured at fair value	2,669		2,430
Investment derivative instruments, liability	'		'
Other derivative instruments, liability	'		'
GLB	193	[1]	1,119	[1]
Total liabilities measured at fair value	193		'
Level 3 | U.S. Treasury and agency	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	'		'
Level 3 | Foreign	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	44		60
Level 3 | Corporate securities	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	166		102
Level 3 | Mortgage backed-securities	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	8		13
Level 3 | States, municipalities, and political subdivisions	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	'		'
Total	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	49,254		47,306
Equity securities	837		744
Short-term investments	1,763		2,228
Other investments	2,976		2,716
Securities lending collateral	1,632		1,791
Investment derivative instruments, assets	19		11
Other derivative instruments, assets	6		24
Separate account assets	1,226		943
Total assets measured at fair value	57,713		55,763
Investment derivative instruments, liability	6		'
Other derivative instruments, liability	62		'
GLB	193	[1]	1,119	[1]
Total liabilities measured at fair value	261		'
Total | U.S. Treasury and agency	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	2,949		3,735
Total | Foreign	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	14,591		13,713
Total | Corporate securities	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	17,470		16,708
Total | Mortgage backed-securities	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	10,894		10,473
Total | States, municipalities, and political subdivisions	'		'
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]	'		'
Fixed maturities available for sale at fair value	$3,350		$2,677
[1]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. Refer to Note 5 c) for additional information.

Fair_Value_Measurements_Fair_V

Fair Value Measurements (Fair Value And Maximum Future Funding Commitments Related To Investments) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair Value	'	'
Fair Value And Maximum Future Funding Commitments Related To Investments [Line Items]	'	'
Financial	256	225
Real estate	322	292
Distressed	180	192
Mezzanine	276	284
Traditional	813	711
Vintage	13	14
Investment funds	428	395
Total of alternative investments	2,288	2,113
Maximum Future Funding Commitments	'	'
Fair Value And Maximum Future Funding Commitments Related To Investments [Line Items]	'	'
Financial	129	111
Real estate	92	62
Distressed	230	152
Mezzanine	252	279
Traditional	456	587
Vintage	'	'
Investment funds	'	'
Total of alternative investments	1,159	1,191
Expected Liquidation Period Lower Range	'	'
Fair Value And Maximum Future Funding Commitments Related To Investments [Line Items]	'	'
Liquidation period for financial alternative investments	'5 years	'5 years
Liquidation period for real estate alternative investments	'3 years	'3 years
Liquidation period for distressed alternative investments	'6 years	'6 years
Liquidation period for mezzanine alternative investments	'6 years	'6 years
Liquidation period for traditional alternative investments	'3 years	'3 years
Liquidation period for vintage alternative investments	'1 year	'1 year
Expected Liquidation Period Upper Range	'	'
Fair Value And Maximum Future Funding Commitments Related To Investments [Line Items]	'	'
Liquidation period for financial alternative investments	'9 years	'9 years
Liquidation period for real estate alternative investments	'9 years	'9 years
Liquidation period for distressed alternative investments	'9 years	'9 years
Liquidation period for mezzanine alternative investments	'9 years	'9 years
Liquidation period for traditional alternative investments	'8 years	'8 years
Liquidation period for vintage alternative investments	'3 years	'3 years

Fair_Value_Measurements_Schedu

Fair Value Measurements (Schedule Of Significant Unobservable Inputs Used In Level 3 Liability Valuations) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Valuation Technique	'Actuarial model	[1]	'		'
Minimum	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Significant Unobservable Inputs Lapse rate	1.00%	[1]	'		'
Significant Unobservable Inputs Annuitization rate	0.00%	[1]	'		'
Maximum	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Significant Unobservable Inputs Lapse rate	30.00%	[1]	'		'
Significant Unobservable Inputs Annuitization rate	55.00%	[1]	'		'
Guaranteed Minimum Income Benefit	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Fair Value	$193	[1]	'		'
Balance - beginning of year, liabilities	1,119	[2],[3]	1,319	[4]	507
Transfers Into Level 3, liabilities	'	[2]	0		0
Transfers out of Level 3, liabilities	'	[2]	0		0
Change in Net Unrealized Gains (Losses) included in OCI, Liabilities	'	[2]	0		'
Net Realized Gains/Losses, Liabilities	-926	[2]	-200		-812
Purchased, liabilities	'	[2]	0		0
Sales, liabilities	'	[2]	0		0
Settlements, liabilities	'	[2]	0		0
Balance - end of year, liabilities	193	[2]	1,119	[2],[3]	1,319	[4]
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Liabilities	-926	[2]	-200		812
Equity securities	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Balance, beginning of year, assets	3		13		13
Transfers into Level 3, assets	8		2		'
Transfers out of Level 3, assets	-1		-11		'
Change in Net Unrealized Gains (Losses) included in OCI, Assets	-6		'		1
Net Realized Gains/Losses, Assets	-4		'		-4
Purchased, assets	2		4		5
Sales, assets	-6		-5		-8
Settlements, assets	'		'		'
Balance, end of year, assets	4		3		13
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	'		'		'
Short-term investments	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Balance, beginning of year, assets	'		'		'
Transfers into Level 3, assets	8		'		'
Transfers out of Level 3, assets	-2		'		'
Change in Net Unrealized Gains (Losses) included in OCI, Assets	'		'		'
Net Realized Gains/Losses, Assets	'		'		'
Purchased, assets	3		'		'
Sales, assets	-1		'		'
Settlements, assets	-1		'		'
Balance, end of year, assets	7		'		'
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	'		'		'
Other Long-term Investments [Member]	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Balance, beginning of year, assets	2,252		1,877		1,432
Transfers into Level 3, assets	'		53		'
Transfers out of Level 3, assets	'		'		'
Change in Net Unrealized Gains (Losses) included in OCI, Assets	45		-55		-93
Net Realized Gains/Losses, Assets	2		7		-3
Purchased, assets	551		520		602
Sales, assets	-10		-9		-55
Settlements, assets	-396		-237		-192
Balance, end of year, assets	2,440		2,252		1,877
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	2		7		3
Other Derivative Instruments Fair Value [Member]	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Balance, beginning of year, assets	'		3		4
Transfers into Level 3, assets	'		0		0
Transfers out of Level 3, assets	'		0		'
Change in Net Unrealized Gains (Losses) included in OCI, Assets	'		0		'
Net Realized Gains/Losses, Assets	'		4		-2
Purchased, assets	'		3		0
Sales, assets	'		0		'
Settlements, assets	'		-2		-3
Balance, end of year, assets	'		'		3
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	'		0		1
Fixed maturities available for sale | U.S. Treasury and agency	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Balance, beginning of year, assets	'		5		'
Transfers into Level 3, assets	'		'		'
Transfers out of Level 3, assets	'		-4		'
Change in Net Unrealized Gains (Losses) included in OCI, Assets	'		'		'
Net Realized Gains/Losses, Assets	'		'		'
Purchased, assets	'		'		5
Sales, assets	'		'		'
Settlements, assets	'		-1		'
Balance, end of year, assets	'		'		5
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	'		'		'
Fixed maturities available for sale | Foreign Government Debt Securities [Member]	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Balance, beginning of year, assets	60		33		26
Transfers into Level 3, assets	36		49		9
Transfers out of Level 3, assets	-54		-13		-18
Change in Net Unrealized Gains (Losses) included in OCI, Assets	'		1		1
Net Realized Gains/Losses, Assets	-1		'		0
Purchased, assets	24		46		23
Sales, assets	-21		-53		-3
Settlements, assets	-2		-1		-3
Balance, end of year, assets	44		60		33
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	'		'		0
Fixed maturities available for sale | Corporate securities	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Balance, beginning of year, assets	102		134		115
Transfers into Level 3, assets	47		37		42
Transfers out of Level 3, assets	-31		-46		-4
Change in Net Unrealized Gains (Losses) included in OCI, Assets	'		-6		2
Net Realized Gains/Losses, Assets	2		1		-3
Purchased, assets	75		24		32
Sales, assets	-7		-19		-27
Settlements, assets	-18		-33		-19
Balance, end of year, assets	166		102		134
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	2		'		0
Fixed maturities available for sale | Mortgage backed-securities	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Balance, beginning of year, assets	13		28		39
Transfers into Level 3, assets	'		22		4
Transfers out of Level 3, assets	'		-35		-48
Change in Net Unrealized Gains (Losses) included in OCI, Assets	'		'		'
Net Realized Gains/Losses, Assets	'		'		'
Purchased, assets	'		9		59
Sales, assets	-3		-7		-17
Settlements, assets	-2		-4		-9
Balance, end of year, assets	8		13		28
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	'		'		'
Fixed maturities available for sale | States, municipalities, and political subdivisions	'		'		'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'		'
Balance, beginning of year, assets	'		1		2
Transfers into Level 3, assets	'		1		'
Transfers out of Level 3, assets	'		-1		'
Change in Net Unrealized Gains (Losses) included in OCI, Assets	'		'		'
Net Realized Gains/Losses, Assets	'		'		'
Purchased, assets	'		'		0
Sales, assets	'		'		'
Settlements, assets	'		-1		-1
Balance, end of year, assets	'		'		1
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	'		'		'
[1]	Discussion of the most significant inputs used in the fair value measurement of GLB and the sensitivity of those assumptions is included within Note 4 a) Guaranteed living benefits.
[2]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. Refer to Note 5 c) for additional information.
[3]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets.
[4]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the consolidated balance sheets. The liability for GLB reinsurance was $1.5 billion at December 31, 2011 and $648 million at December 31, 2010, which includes a fair value derivative adjustment of $1.3 billion and $507 million, respectively.

Fair_Value_Measurements_Carryi

Fair Value Measurements (Carrying Values And Fair Values Of Financial Instruments Not Measured At Fair Value) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Financial Instruments Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	$6,263	$7,633
Partially-owned insurance companies	470	454
Total assets	6,733	8,087
Short-term debt	1,913	1,401
Long-term debt	4,088	3,916
Trust preferred securities	438	446
Total liabilities	6,439	5,763
Financial Instruments Fair Value [Member] | US Treasury and Government [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	832	1,083
Financial Instruments Fair Value [Member] | Foreign	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	897	964
Financial Instruments Fair Value [Member] | Corporate Debt Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	2,005	2,275
Financial Instruments Fair Value [Member] | Collateralized Mortgage Backed Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	1,379	2,116
Financial Instruments Fair Value [Member] | US States and Political Subdivisions Debt Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	1,150	1,195
Level 2 | Financial Instruments Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	5,652	6,996
Total assets	5,652	6,996
Short-term debt	1,913	1,401
Long-term debt	4,088	3,916
Trust preferred securities	438	446
Total liabilities	6,439	5,763
Level 2 | Financial Instruments Fair Value [Member] | US Treasury and Government [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	236	464
Level 2 | Financial Instruments Fair Value [Member] | Foreign	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	897	964
Level 2 | Financial Instruments Fair Value [Member] | Corporate Debt Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	1,990	2,257
Level 2 | Financial Instruments Fair Value [Member] | Collateralized Mortgage Backed Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	1,379	2,116
Level 2 | Financial Instruments Fair Value [Member] | US States and Political Subdivisions Debt Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	1,150	1,195
Level 3 | Financial Instruments Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	15	18
Partially-owned insurance companies	470	454
Total assets	485	472
Short-term debt	'	0
Long-term debt	'	0
Trust preferred securities	'	0
Total liabilities	'	0
Level 3 | Financial Instruments Fair Value [Member] | US Treasury and Government [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	0	0
Level 3 | Financial Instruments Fair Value [Member] | Foreign	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	'	0
Level 3 | Financial Instruments Fair Value [Member] | Corporate Debt Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	15	18
Level 3 | Financial Instruments Fair Value [Member] | Collateralized Mortgage Backed Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	'	0
Level 3 | Financial Instruments Fair Value [Member] | US States and Political Subdivisions Debt Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	'	0
Cost | Financial Instruments Carrying Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	6,098	7,270
Partially-owned insurance companies	470	454
Total assets	6,568	7,724
Short-term debt	1,901	1,401
Long-term debt	3,807	3,360
Trust preferred securities	309	309
Total liabilities	6,017	5,070
Cost | Financial Instruments Carrying Value [Member] | US Treasury and Government [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	820	1,044
Cost | Financial Instruments Carrying Value [Member] | Foreign	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	864	910
Cost | Financial Instruments Carrying Value [Member] | Corporate Debt Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	1,922	2,133
Cost | Financial Instruments Carrying Value [Member] | Collateralized Mortgage Backed Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	1,341	2,028
Cost | Financial Instruments Carrying Value [Member] | US States and Political Subdivisions Debt Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	1,151	1,155
Level 1 | Financial Instruments Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	596	619
Total assets	596	619
Short-term debt	'	0
Long-term debt	'	0
Trust preferred securities	'	0
Total liabilities	'	0
Level 1 | Financial Instruments Fair Value [Member] | US Treasury and Government [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	596	619
Level 1 | Financial Instruments Fair Value [Member] | Foreign	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	'	0
Level 1 | Financial Instruments Fair Value [Member] | Corporate Debt Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	'	0
Level 1 | Financial Instruments Fair Value [Member] | Collateralized Mortgage Backed Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	'	0
Level 1 | Financial Instruments Fair Value [Member] | US States and Political Subdivisions Debt Securities [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Total Fixed maturities held to maturity	'	$0

Reinsurance_Consolidated_Reins

Reinsurance (Consolidated Reinsurance) (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
Premiums written [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Direct	'	'	'	'	'	'	'	'	$19,212	$18,144	$17,626
Assumed	'	'	'	'	'	'	'	'	3,616	3,449	3,205
Ceded	'	'	'	'	'	'	'	'	-5,803	-5,518	-5,459
Net	'	'	'	'	'	'	'	'	17,025	16,075	15,372
Premiums earned [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Direct	'	'	'	'	'	'	'	'	18,856	17,802	17,534
Assumed	'	'	'	'	'	'	'	'	3,479	3,302	3,349
Ceded	'	'	'	'	'	'	'	'	-5,722	-5,427	-5,496
Net premiums earned	$4,363	$4,610	$4,067	$3,573	$3,848	$4,665	$3,783	$3,381	$16,613	$15,677	$15,387

Reinsurance_Reinsurance_Recove

Reinsurance (Reinsurance Recoverable on Ceded Reinsurance) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Reinsurance Disclosures [Abstract]	'	'	'	'
Reinsurance recoverable on unpaid losses and loss expenses	$10,612	$11,399	$11,602	$12,149
Reinsurance recoverable on paid losses and loss expenses	615	679	'	'
Net reinsurance recoverable on losses and loss expenses	$11,227	$12,078	'	'

Reinsurance_Reinsurance_Recove1

Reinsurance (Reinsurance Recoverable by Category and Listing of Largest Reinsurers) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]	'	'
2012	$11,617	'
Provision	390	439
% of Gross	3.40%	'
Largest reinsurers	'	'
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]	'	'
2012	5,117	'
Provision	78	'
% of Gross	1.50%	'
Other reinsurers balances rated A- or better	'	'
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]	'	'
2012	2,901	'
Provision	36	'
% of Gross	1.20%	'
Other reinsurers balances with ratings lower than A- or not rated	'	'
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]	'	'
2012	587	'
Provision	103	'
% of Gross	17.50%	'
Other pools and government agencies	'	'
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]	'	'
2012	338	'
Provision	21	'
% of Gross	6.20%	'
Structured settlements	'	'
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]	'	'
2012	577	'
Provision	12	'
% of Gross	2.10%	'
Other captives	'	'
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]	'	'
2012	1,762	'
Provision	14	'
% of Gross	0.80%	'
Other	'	'
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]	'	'
2012	335	'
Provision	$126	'
% of Gross	37.60%	'

Reinsurance_Reinsurance_Assume

Reinsurance Reinsurance (Assumed Life Reinsurance Programs Involving Minimum Benefit Guarantees Under Annuity Contracts - Schedule Of Guaranteed Minimum Benefits Income And Expense) (Detail) (USD $)	3 Months Ended								12 Months Ended
	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
Guaranteed Minimum Benefits [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	$4,363,000,000	$4,610,000,000	$4,067,000,000	$3,573,000,000	$3,848,000,000	$4,665,000,000	$3,783,000,000	$3,381,000,000	$16,613,000,000	$15,677,000,000	$15,387,000,000
Policy benefits and other reserve adjustments	136,000,000	138,000,000	110,000,000	131,000,000	142,000,000	130,000,000	102,000,000	147,000,000	515,000,000	521,000,000	401,000,000
Net realized gains (losses) including OTTI	154,000,000	40,000,000	104,000,000	206,000,000	272,000,000	-60,000,000	-394,000,000	260,000,000	504,000,000	78,000,000	-795,000,000
GMDB	'	'	'	'	'	'	'	'	'	'	'
Guaranteed Minimum Benefits [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	77,000,000	85,000,000	98,000,000
Policy benefits and other reserve adjustments	'	'	'	'	'	'	'	'	73,000,000	60,000,000	59,000,000
GLB	'	'	'	'	'	'	'	'	'	'	'
Guaranteed Minimum Benefits [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	149,000,000	160,000,000	163,000,000
Policy benefits and other reserve adjustments	'	'	'	'	'	'	'	'	27,000,000	61,000,000	47,000,000
Net realized gains (losses) including OTTI	'	'	'	'	'	'	'	'	929,000,000	203,000,000	-812,000,000
Gain (loss) recognized in income	'	'	'	'	'	'	'	'	1,051,000,000	302,000,000	-696,000,000
Net cash received	'	'	'	'	'	'	'	'	126,000,000	149,000,000	161,000,000
Net (increase) decrease in liability	'	'	'	'	'	'	'	'	$925,000,000	$153,000,000	($857,000,000)

Reinsurance_Assumed_Life_Reins

Reinsurance (Assumed Life Reinsurance Programs Involving Minimum Benefit Guarantees Under Annuity Contracts - Narrative) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
				Guaranteed Minimum Death Benefit	Guaranteed Minimum Death Benefit	Guaranteed Minimum Deaths Benefits And Guaranteed Living Benefits [Member]	Guaranteed Minimum Deaths Benefits And Guaranteed Living Benefits [Member]	Guaranteed Living Benefits [Member]	Guaranteed Living Benefits [Member]	Guaranteed Living Benefits [Member]	Guaranteed Living Benefits [Member]
Guaranteed Minimum Benefits [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Reinsurance recoveries on losses and loss expenses incurred	$3,100,000,000	$4,300,000,000	$3,300,000,000	'	'	'	'	'	'	'	'
Provision for uncollectible reinsurance	390,000,000	439,000,000	'	'	'	'	'	'	'	'	'
Reported liabilities	'	'	'	100,000,000	90,000,000	'	'	427,000,000,000	1,400,000,000	1,500,000,000	648,000,000
Fair value derivative adjustment in liability	'	'	'	'	'	'	'	0	1,100,000,000	'	'
Net amount at risk	'	'	'	586,000,000,000	1,300,000,000	'	'	136,000,000	445,000,000	'	'
Mortality percentage according to Annuity 2000 mortality table	'	'	'	'	'	100.00%	'	'	'	'	'
Discounting assumption used in the calculation of the benefit reserve averaging - lower range	'	'	'	2.00%	'	3.00%	'	3.50%	'	'	'
Discounting assumption used in the calculation of the benefit reserve averaging - upper range	'	'	'	3.00%	'	4.00%	'	4.50%	'	'	'
Total claim amount payable, if all of the Company's cedants' policyholders covered were to die immediately	'	'	'	668,000,000	'	84,000,000	'	'	'	'	'
GMBD net amount of risk	'	'	'	'	'	73,000,000	116,000,000	'	'	'	'
GLB net amount of risk	'	'	'	'	'	$141,000,000	$655,000,000	'	'	'	'
Average attained age of all policyholders under all benefits reinsured, years	'68 years	'	'	'	'	'	'	'	'	'	'

intangible_Assets_Narrative_De

intangible Assets (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'
Goodwill	$4,603	$4,319	$4,148
Other intangible assets	801	656	'
Intangible assets subject to amortization	695	554	'
Intangible assets not subject to amortization	106	102	'
Amortization expense related to other intangible assets	$95	$51	$29

Intangible_Assets_Rollforward_

Intangible Assets (Roll-forward of Goodwill, by Business Segment) (Details) (USD $)

12 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Feb. 02, 2011

Dec. 31, 2013

Apr. 02, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

2-May-13

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American Agriculture

Insurance - North American Agriculture

Insurance - Overseas General

Insurance - Overseas General

Global Reinsurance

Global Reinsurance

Life

Life

New York Life's Korea and Hong Kong

Fianzas Monterrey

Fianzas Monterrey

Fianzas Monterrey

Fianzas Monterrey

Fianzas Monterrey

Fianzas Monterrey

JaPro

JaPro

JaPro

JaPro

JaPro

JaPro

ABA Seguros

ABA Seguros

ABA Seguros

ABA Seguros

ABA Seguros

ABA Seguros

Insurance - North American P&C

Insurance - Overseas General

Global Reinsurance

Life

Insurance - North American P&C

Insurance - North American Agriculture

Insurance - Overseas General

Global Reinsurance

Life

Insurance - North American P&C

Insurance - Overseas General

Global Reinsurance

Life

Goodwill [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance at beginning of period

$4,319

$4,148

$1,219

$1,216

$134

$134

$1,764

$1,603

$365

$365

$837

$830

$91

'

$135

'

'

'

'

'

'

'

'

'

'

'

$283

'

'

'

'

Purchase price allocation adjustment

'

4

'

0

0

0

'

0

'

0

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Acquisition

'

'

'

'

'

'

'

'

'

'

'

'

'

135

'

0

135

0

0

123

0

0

123

0

0

283

'

0

283

0

0

Foreign exchange revaluation and other

-134

44

-4

3

0

0

-128

38

0

0

-2

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance at end of period

$4,603

$4,319

$1,215

$1,219

$134

$134

$2,054

$1,764

$365

$365

$835

$837

$91

'

$135

'

'

'

'

'

'

'

'

'

'

'

$283

'

'

'

'

Intangible_Assets_Value_Of_Bus

Intangible Assets (Value Of Business Acquired (VOBA) Roll-forward) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Movement in Intangible Assets Arising from Insurance Contracts Acquired in Business Combination [Roll Forward]	'	'	'
Balance, beginning of year	$614	$676	$634
Acquisition of New York Life's Korea operations and Hong Kong operations	0	0	151
Amortization expense	-64	-82	-108
Foreign exchange revaluation	-14	20	-1
Balance, end of year	$536	$614	$676

Intangible_Assets_Estimated_Am

Intangible Assets (Estimated Amortization Expense Over Next Five Years) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]	'
2014	$81
2015	62
2016	55
2017	52
2018	49
Total	299
Intangible Assets Arising from Insurance Contracts Acquired in Business Combination, Amortization Expense, Fiscal Year Maturity [Abstract]	'
2014	55
2015	50
2016	45
2017	40
2018	35
Total	$225

Unpaid_losses_and_loss_expense2

Unpaid losses and loss expenses (Narrative) (Details) (USD $)

12 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2004

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2011

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 1998

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Insurance - Overseas General

Insurance - Overseas General

Insurance - Overseas General

Global Reinsurance

Global Reinsurance

Global Reinsurance

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Short tail

Short tail

Short tail

Short tail

Short tail

Short tail

Short tail

Short tail

Short tail

Short tail

Short tail

Insurance - Overseas General

Insurance - Overseas General

Global Reinsurance

Penn Millers

Brandywine

Brandywine

Westchester Specialty

Westchester Specialty

Westchester Specialty

Ace Bermuda [Member]

Net of NICO Coverage

Net of NICO Coverage

Run Off [Member]

Run Off [Member]

Run Off [Member]

Run Off [Member]

Run Off [Member]

Run Off [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Active [Member]

Insurance - Overseas General

Insurance - Overseas General

Global Reinsurance

Excess casualty business

Excess casualty business

Excess casualty business

Excess casualty business

Excess casualty business

Medical risk operations

Medical risk operations

Financial solutions business

Financial solutions business

Financial solutions business

Non Medical Professional Liability [Member]

Insurance - Overseas General

Other lines

Other lines

Other lines

Property portfolios

Property portfolios

Property portfolios

Property portfolios

Property portfolios

Property portfolios

Aviation lines [Domain]

Brandywine

Westchester Specialty

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Completion of reserve review

Completion of reserve review

Insurance - North American

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Long tail

Short tail

Short tail

Short tail

Short tail

Short tail

Short tail

Insurance - North American

Insurance - Overseas General

2009 and prior

2009 and prior

2008 and prior

2008 and prior

2009 and prior

2008 and prior

Insurance - Overseas General

2009 and prior

2012

2008 and prior

Insurance - North American Agriculture

Insurance - North American Agriculture

Insurance - North American Agriculture

Insurance - Overseas General

2009 to 2010

2008 to 2009

2009 and prior

2009 and prior

2008 and prior

2009 and prior

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Directors and Officers (D&O) Portfolio

Directors and Officers (D&O) Portfolio

Excess casualty business

Excess casualty business

Medical risk operations

Medical risk operations

National accounts portfolio

National accounts portfolio

National accounts portfolio

Foreign casualty Products

Other lines

Completion of reserve review

Workers Compensation [Domain]

Workers Compensation [Domain]

Workers Compensation [Domain]

Insurance - North American P&C

Insurance - North American P&C

Property and inland marine lines

Property and inland marine lines

Political risk lines [Domain]

Aviation lines [Domain]

Insurance - Overseas General

Insurance - Overseas General

Insurance - Overseas General

Insurance - Overseas General

Global Reinsurance

Global Reinsurance

Insurance - Overseas General

Insurance - Overseas General

Global Reinsurance

Insurance - Overseas General

Insurance - Overseas General

Global Reinsurance

Global Reinsurance

Insurance - Overseas General

Insurance - Overseas General

2007 and prior

2008 and prior

2007 and prior

2007 and prior

2007 and prior

2007 to 2009

Insurance - North American P&C

2007 and prior

2012

2009 and prior

Insurance - North American P&C

2012

2006 and prior

2006 and prior

2007 and prior

2008 to 2010

2009 and prior

2009 to 2010

2009 and prior

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Insurance - North American P&C

Unpaid Losses and Loss Expenses [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net losses and loss expenses incurred in prior years

$530,000,000

$479,000,000

$556,000,000

'

$299,000,000

$226,000,000

$290,000,000

$84,000,000

$61,000,000

$71,000,000

$127,000,000

$121,000,000

$53,000,000

$92,000,000

$135,000,000

($29,000,000)

($43,000,000)

$150,000,000

$20,000,000

$54,000,000

$35,000,000

$63,000,000

($28,000,000)

$25,000,000

$172,000,000

$13,000,000

$12,000,000

$8,000,000

$104,000,000

$105,000,000

$69,000,000

$31,000,000

$29,000,000

$35,000,000

$29,000,000

'

'

'

'

'

'

'

'

'

'

'

'

($193,000,000)

($168,000,000)

($102,000,000)

($161,000,000)

($150,000,000)

'

$327,000,000

$348,000,000

($289,000,000)

$221,000,000

$245,000,000

$67,000,000

$72,000,000

$50,000,000

$73,000,000

$57,000,000

$63,000,000

$28,000,000

$39,000,000

$40,000,000

$25,000,000

$28,000,000

$41,000,000

($40,000,000)

($36,000,000)

$34,000,000

$106,000,000

$103,000,000

$88,000,000

$45,000,000

$29,000,000

$27,000,000

'

Prior period net unpaid reserves represented by prior period development (percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-4.20%

-3.10%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-0.60%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-1.80%

Unallocated loss adjustment expenses due to operating expenses paid and reserved

-9,878,000,000

-10,132,000,000

-10,076,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

A & E - change in net loss reserves

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

166,000,000

146,000,000

5,000,000

4,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

A & E - change in gross loss reserves

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

277,000,000

275,000,000

3,000,000

-17,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

A & E - loss reserves, net - closing

1,051,000,000

1,106,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

79,000,000

'

'

3,000,000

816,000,000

'

146,000,000

'

'

7,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

A & E - incurred activity, net

171,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

158,000,000

'

14,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

NICO reinsurance protection on losses and loss expenses

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Incurred activity

9,348,000,000

9,653,000,000

9,520,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

167,000,000

1,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

NICO pro-rata share of reinsurance protection (percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

75.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

NICO reinsurance protection on losses and loss expenses incurred on or before 12/31/1996, net of retenion

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

NICO retention for losses and loss expenses incurred on or before 12/31/1996

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

721,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

NICO remaining unused limit under the 1998 agreement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

490,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Dividend retention fund established by INA Financial Corporation

50,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Required minimum balance under the dividend retention fund

50,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum contribution from the dividend retention fund to Century not required for XOL agreement

200,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Reinsurance coverage to Century provided by ACE INA under XOL

800,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Statutory surplus of century

25,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Century Statutory Basis Losses Cede To X O L

232,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

INA Holdings contibutions to Century in exchange for a surplus note

'

'

'

100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate reinsurance balances ceded by active ACE companies to Century

929,000,000

958,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Century's carried gross reserves (including reserves ceded by active ACE companies)

$2,300,000,000

$2,100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unpaid_losses_and_loss_expense3

Unpaid losses and loss expenses (Unpaid Losses and Loss Expenses Rollforward) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Unpaid Losses and Loss Expenses [Roll Forward]	'	'	'
Gross unpaid losses and loss expenses, beginning of year	$37,946	$37,477	$37,391
Reinsurance recoverable on unpaid losses	11,399	11,602	12,149
Balance at beginning of year	26,547	25,875	25,242
Acquistion of subsidiaries	86	14	92
Total	26,633	25,889	25,334
Net losses and loss expenses incurred in respect of losses incurring in Current Year	9,878	10,132	10,076
Net losses and loss expenses incurred in respect of losses incurring in Prior Year	-530	-479	-556
Total	9,348	9,653	9,520
Net losses and loss expenses incurred in respect of losses paid in Current Year	3,942	4,325	4,209
Net losses and loss expenses incurred in respect of losses paid in Prior Year	5,035	4,894	4,657
Total	8,977	9,219	8,866
Foreign currency revaluation and other	-173	224	-113
Balance at end of year	26,831	26,547	25,875
Reinsurance recoverable on unpaid losses	10,612	11,399	11,602
Gross unpaid losses and loss expenses, end of year	$37,443	$37,946	$37,477

Unpaid_losses_and_loss_expense4

Unpaid losses and loss expenses (A&E Loss Roll-forward) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Unpaid Losses and Loss Expenses [Roll Forward]	'
Balance (gross) at December 31, 2012	$2,080
Balance (net) at December 31, 2012	1,106
Incurred activity, gross	244
Incurred activity, net	171
Paid activity, gross	-485
Paid activity, net	-226
Balance (gross) at December 31, 2013	1,839
Balance (net) at December 31, 2013	1,051
Asbestos	'
Unpaid Losses and Loss Expenses [Roll Forward]	'
Balance (gross) at December 31, 2012	1,886
Balance (net) at December 31, 2012	970
Incurred activity, gross	125
Incurred activity, net	96
Paid activity, gross	-367
Paid activity, net	-140
Balance (gross) at December 31, 2013	1,644
Balance (net) at December 31, 2013	926
Environmental	'
Unpaid Losses and Loss Expenses [Roll Forward]	'
Balance (gross) at December 31, 2012	194
Balance (net) at December 31, 2012	136
Incurred activity, gross	119
Incurred activity, net	75
Paid activity, gross	-118
Paid activity, net	-86
Balance (gross) at December 31, 2013	195
Balance (net) at December 31, 2013	$125

Unpaid_losses_and_loss_expense5

Unpaid losses and loss expenses (Brandywine Incurred Loss Activity) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	$26,547		$25,875	$25,242
Incurred activity	9,348		9,653	9,520
Paid activity	8,977		9,219	8,866
Balance at end of year	26,831		26,547	25,875
Brandywine | A&E	'		'	'
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	852		'	'
Incurred activity	158		'	'
Paid activity	-194		'	'
Balance at end of year	816		'	'
Brandywine | Other	'		'	'
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	421	[1]	'	'
Incurred activity	9	[1]	'	'
Paid activity	-63	[1]	'	'
Balance at end of year	367	[1]	'	'
Brandywine | Total	'		'	'
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	1,273		'	'
Incurred activity	167		'	'
Paid activity	-257		'	'
Balance at end of year	1,183		'	'
Brandywine | NICO Coverage	'		'	'
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	18		'	'
Incurred activity	0		'	'
Paid activity	-18		'	'
Balance at end of year	0		'	'
Brandywine | Net of NICO Coverage	'		'	'
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	1,255		'	'
Incurred activity	167		'	'
Paid activity	-239		'	'
Balance at end of year	$1,183		'	'
[1]	e

Unpaid_losses_and_loss_expense6

Unpaid losses and loss expenses (Westchester Incurred Loss Activity) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	$26,547		$25,875	$25,242
Incurred activity	9,348		9,653	9,520
Paid activity	8,977		9,219	8,866
Balance at end of year	26,831		26,547	25,875
Westchester Specialty | A&E	'		'	'
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	151		'	'
Incurred activity	14		'	'
Paid activity	-19		'	'
Balance at end of year	146		'	'
Westchester Specialty | Other	'		'	'
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	44	[1]	'	'
Incurred activity	-11	[1]	'	'
Paid activity	0	[1]	'	'
Balance at end of year	33	[1]	'	'
Westchester Specialty | Total	'		'	'
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	195		'	'
Incurred activity	3		'	'
Paid activity	-19		'	'
Balance at end of year	179		'	'
Westchester Specialty | NICO Coverage	'		'	'
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	158		'	'
Incurred activity	2		'	'
Paid activity	-19		'	'
Balance at end of year	141		'	'
Westchester Specialty | Net of NICO Coverage	'		'	'
Unpaid Losses and Loss Expenses [Roll Forward]	'		'	'
Balance at beginning of year	37		'	'
Incurred activity	1		'	'
Paid activity	0		'	'
Balance at end of year	$38		'	'
[1]	e

Taxation_Narrative_Details

Taxation (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Examination [Line Items]	'	'	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$22	$18	'
Valuation allowance	64	56	'
Unrecognized tax benefits that would affect the effective tax rate	5	'	'
Tax-related interest and penalties reported in the consolidated statements of operations	-1	-8	3
Liabilities recorded for tax-related interest and penalties	11	12	'
Domestic Tax Authority [Member]	'	'	'
Income Tax Examination [Line Items]	'	'	'
Net operating loss carry-forwards	154	'	'
Switzerland	'	'	'
Income Tax Examination [Line Items]	'	'	'
Applicable income tax rates	7.83%	'	'
Foreign Tax Authority [Member]	'	'	'
Income Tax Examination [Line Items]	'	'	'
Foreign tax credit carry-forward	$131	'	'
Bermuda	'	'	'
Income Tax Examination [Line Items]	'	'	'
Applicable income tax rates	0.00%	'	'
U.S.	'	'	'
Income Tax Examination [Line Items]	'	'	'
Applicable income tax rates	35.00%	'	'
U.K.	'	'	'
Income Tax Examination [Line Items]	'	'	'
Applicable income tax rates	23.25%	'	'

Taxation_Provision_For_Income_

Taxation (Provision For Income Taxes) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Current tax expense	$231	$305	$485
Deferred tax expense	249	-35	17
Provision for income taxes	$480	$270	$502

Taxation_Reconciliation_Of_The

Taxation (Reconciliation Of The Difference Between The Provision for Income Taxes and the Expected Tax Provision at Swiss Statutory Income Tax Rate) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Expected tax provision at Swiss statutory rate	$331	$233	$160
Taxes on earnings subject to rates other that Swiss statutory rate	124	129	323
Tax exempt interest and dividends received deduction, net of proration	-27	-24	-21
Net witholding taxes	27	23	19
Favorable resolution of prior years' tax matters and closing of statutes of limitations	-5	-124	0
Change in valuation allowance	4	4	-2
Other	26	29	23
Provision for income taxes	$480	$270	$502

Taxation_Components_Of_Net_Def

Taxation (Components Of Net Deferred Tax Assets) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Deferred Tax Assets, Gross [Abstract]	'	'
Loss reserve discount	$807	$849
Unearned premium reserve	93	98
Foreign tax credits	1,236	1,131
Investments	3	43
Provision for uncollectible balances	78	110
Loss carry-forwards	54	55
Other, net	184	110
Total deferred tax assets	2,455	2,396
Deferred Tax Liabilities, Gross [Abstract]	'	'
Deferred policy acquisition costs	138	68
VOBA and other intangible assets	351	379
Un-remitted foreign earnings	982	795
Unrealized appreciation on investments	210	586
Deferred Tax Liabilities, Unrealized Currency Transaction Gains	94	59
Total deferred tax liabilities	1,775	1,887
Valuation allowance	64	56
Net deferred tax assets	$616	$453

Taxation_Reconciliation_of_Unr

Taxation (Reconciliation of Unrecognized Tax Benefits) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]	'	'
Unrecognized Tax Benefits, beginning of year	$26	$134
Additions based on tax provisions related to the current year	5	19
Reductions for settlements with tax authorities	0	-16
Reductions for the lapse of the applicable statutes of limitations	-4	-111
Unrecognized Tax Benefits, end of year	$27	$26

Debt_Narrative_Details

Debt (Narrative) (Details) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Mar. 31, 2000

Dec. 31, 2013

Dec. 31, 2012

In Millions, unless otherwise specified

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior Notes

Senior secured debentures

Senior secured debentures

Trust Preferred Securities

Trust Preferred Securities

Reverse repurchase agreements

Reverse repurchase agreements

ACE INA senior notes due 2014

ACE INA senior notes due 2014

ACE INA senior notes due 2015

ACE INA senior notes due 2015

ACE INA senior notes due 2015

ACE INA senior notes due 2015

ACE INA senior notes due 2017

ACE INA senior notes due 2017

ACE INA senior notes due 2018

ACE INA senior notes due 2018

ACE INA senior notes due 2019

ACE INA senior notes due 2019

ACE INA senior notes due 2036

ACE INA senior notes due 2036

ACE INA debentures due 2029

ACE INA debentures due 2029

ACE INA capital securities due 2030

ACE INA capital securities due 2030

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Short-term debt

$1,901

$1,401

'

'

$500

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1,401

$1,401

Debt issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

309

300

'

'

Long-term debt stated interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9.70%

9.70%

'

'

Current amount of long-term debt outstanding

3,807

3,360

3,807

3,360

0

500

449

449

700

699

500

500

300

300

500

500

299

299

100

100

'

'

'

'

ACE Capital Trust II common securities purchased

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$9.20

'

'

Debt_Schedule_of_Debt_Outstand

Debt (Schedule of Debt Outstanding) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'	'
Short-term debt	$1,901	$1,401
Long-term debt	3,807	3,360
Trust preferred securities	309	309
Senior Notes	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	3,807	3,360
Senior Notes | ACE INA senior notes due 2014	'	'
Debt Instrument [Line Items]	'	'
Short-term debt	500	0
Long-term debt	0	500
Senior Notes | ACE INA senior notes due 2015	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	449	449
Senior Notes | ACE INA senior notes due 2015	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	700	699
Senior Notes | ACE INA senior notes due 2017	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	500	500
Senior Notes | ACE INA senior notes due 2018	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	300	300
Senior Notes | ACE INA senior notes due 2019	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	500	500
Senior Notes | ACE INA senior notes due 2023	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	473	0
Senior Notes | ACE INA senior notes due 2036	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	299	299
Senior Notes | ACE INA senior notes due 2043	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	474	0
Senior Notes | Other	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	12	13
Senior secured debentures | ACE INA debentures due 2029	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	100	100
Trust Preferred Securities | ACE INA capital securities due 2030	'	'
Debt Instrument [Line Items]	'	'
Trust preferred securities	309	309
Reverse repurchase agreements	'	'
Debt Instrument [Line Items]	'	'
Short-term debt	$1,401	$1,401

Commitments_contingencies_and_2

Commitments, contingencies, and guarantees (Narrative) (Detail) (USD $)	2 Months Ended	12 Months Ended
	Feb. 27, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
		derivative
Commitments Contingencies And Guarantees [Line Items]	'	'	'	'
Derivative Asset, Fair Value, Amount Offset Against Collateral	'	($41,000,000)	'	'
Derivative Liability, Fair Value, Amount Offset Against Collateral	'	'	35,000,000	'
Securities Sold under Agreements to Repurchase	'	1,401,000,000	1,401,000,000	'
Obligation to Return Securities Received as Collateral	'	1,633,000,000	1,795,000,000	'
Securities Held as Collateral, at Fair Value	'	1,632,000,000	1,791,000,000	'
Repurchase of outstanding common shares, shares	3,437,082	3,266,531	100,000	2,058,860
Number of in-force interest rate swaps	'	0	'	'
Number of in-force credit default swaps	'	0	'	'
Approximate percentage of gross premiums written that were generated from or placed by Marsh	'	11.00%	11.00%	12.00%
Approximate percentage of gross premiums written that were generated from or placed by Aon	'	'	'	10.00%
Carrying value of limited partnerships and partially-owned investment companies included in other investments	'	1,900,000,000	'	'
Funding commitments relating to limited partnerships and partially-owned investment companies	'	1,200,000,000	'	'
Total rental expense related to operating leases	'	128,000,000	112,000,000	114,000,000
Cost of shares acquired	326,000,000	290,000,000	7,000,000	132,000,000
Letter of Credit [Member]	'	'	'	'
Commitments Contingencies And Guarantees [Line Items]	'	'	'	'
Line of Credit Facility, Current Borrowing Capacity	'	1,000,000,000	'	'
Letter Of Credit Unsecured Expiring November 2017 | Letter of Credit [Member]	'	'	'	'
Commitments Contingencies And Guarantees [Line Items]	'	'	'	'
Borrowing capacity on unsecured revolving line of credit	'	1,500,000,000	'	'
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases	'	300,000,000	'	'
Line of Credit Facility, Amount Outstanding	'	376,000,000	'	'
Letter Of Credit Unsecured Expiring September 2014 | Letter of Credit [Member]	'	'	'	'
Commitments Contingencies And Guarantees [Line Items]	'	'	'	'
Borrowing capacity on unsecured revolving line of credit	'	500,000,000	'	'
Letter Of Credit Bilateral Uncollateralized Expiring December 2017 | Letter of Credit [Member]	'	'	'	'
Commitments Contingencies And Guarantees [Line Items]	'	'	'	'
Borrowing capacity on unsecured revolving line of credit	'	425,000,000	'	'
Line of Credit Facility, Amount Outstanding	'	352,000,000	'	'
November 2013 Stock Repurchase Plan [Member]	'	'	'	'
Commitments Contingencies And Guarantees [Line Items]	'	'	'	'
Share repurchase authorization remaining	$1,620,000,000	$1,940,000,000	'	'

Commitments_contingencies_and_3

Commitments, contingencies, and guarantees (Balance Sheet Locations, Fair Values In Asset Or (Liability) Position, And Notional Values/Payment Provisions Of Derivative Instruments) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Notional Value/Payment Provision	$6,287	$0
Foreign Exchange Future [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional Value/Payment Provision	1,202	0
Cross Currency Swap [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional Value/Payment Provision	50	0
Futures Contracts On Money Market Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional Value/Payment Provision	3,910	0
Futures contracts on notes and bonds [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional Value/Payment Provision	871	0
Convertibles and Bonds with Warrants Attached [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional Value/Payment Provision	254	0
Single-Stock Future [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional Value/Payment Provision	1,692	0
Options On Equity Market Indices [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional Value/Payment Provision	250	0
Other	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional Value/Payment Provision	8	0
Other Derivative Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional Value/Payment Provision	1,950	0
Guaranteed Living Benefits [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional Value/Payment Provision	277	0
Other Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	321	0
Other Assets [Member] | Foreign Exchange Future [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	3	0
Other Assets [Member] | Cross Currency Swap [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	0	0
Other Assets [Member] | Futures Contracts On Money Market Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	3	0
Other Assets [Member] | Futures contracts on notes and bonds [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	13	0
Other Assets [Member] | Single-Stock Future [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	0	0
Other Assets [Member] | Options On Equity Market Indices [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	6	0
Other Assets [Member] | Other	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	0	0
Other Assets [Member] | Other Derivative Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	6	0
Other Assets [Member] | Guaranteed Living Benefits [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	0	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	-6	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Foreign Exchange Future [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	-4	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Cross Currency Swap [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	0	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Futures Contracts On Money Market Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	0	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Futures contracts on notes and bonds [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	-2	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Convertibles and Bonds with Warrants Attached [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	0	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Single-Stock Future [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	-60	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Options On Equity Market Indices [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	0	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Other	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	-2	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Other Derivative Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	-62	0
Fixed Maturities Available For Sale [Member] | Convertibles and Bonds with Warrants Attached [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	302	0
Accounts Payable Future Policy Benefits [Member] | Guaranteed Living Benefits [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value	($427)	$0

Commitments_contingencies_and_4

Commitments, contingencies, and guarantees (Net Realized Gains (Losses) Of Derivative Instrument Activity In Consolidated Statement Of Operations) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Commitments Contingencies And Guarantees [Line Items]	'		'		'
Net realized gains (losses)	$375		($136)		($930)
Foreign Exchange Future [Member]	'		'		'
Commitments Contingencies And Guarantees [Line Items]	'		'		'
Net realized gains (losses)	11		-9		6
All Other Futures Contracts And Options [Member]	'		'		'
Commitments Contingencies And Guarantees [Line Items]	'		'		'
Net realized gains (losses)	61		-22		-98
Convertibles and Bonds with Warrants Attached [Member]	'		'		'
Commitments Contingencies And Guarantees [Line Items]	'		'		'
Net realized gains (losses)	6		25		-50
Dollar Rolls [Member]	'		'		'
Commitments Contingencies And Guarantees [Line Items]	'		'		'
Net realized gains (losses)	0		0		-1
Investment And Embedded Derivative Instruments [Member]	'		'		'
Commitments Contingencies And Guarantees [Line Items]	'		'		'
Net realized gains (losses)	78		-6		-143
Guaranteed Living Benefits [Member]	'		'		'
Commitments Contingencies And Guarantees [Line Items]	'		'		'
Net realized gains (losses)	878	[1]	171	[1]	-779	[1]
Single-Stock Future [Member]	'		'		'
Commitments Contingencies And Guarantees [Line Items]	'		'		'
Net realized gains (losses)	-555	[2]	-273	[2]	-12	[2]
Options On Equity Market Indices [Member]	'		'		'
Commitments Contingencies And Guarantees [Line Items]	'		'		'
Net realized gains (losses)	-24	[2]	-24	[2]	8	[2]
Credit Default Swap [Member]	'		'		'
Commitments Contingencies And Guarantees [Line Items]	'		'		'
Net realized gains (losses)	-2		-4		-4
Guaranteed Living Benefit And Other Derivative Instruments [Member]	'		'		'
Commitments Contingencies And Guarantees [Line Items]	'		'		'
Net realized gains (losses)	$297		($130)		($787)
[1]	Excludes foreign exchange gains (losses) related to GLB.
[2]	Related to GMDB and GLB blocks of business.

Commitments_contingencies_and_5

Commitments, contingencies, and guarantees (Future Minimum Lease Payments) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'
2014	$106
2015	99
2016	86
2017	70
2018	49
Thereafter	124
Total minimum future lease commitments	$534

Shareholders_equity_Detail

Shareholders' equity (Detail)

2 Months Ended

12 Months Ended

0 Months Ended

2 Months Ended

12 Months Ended

Feb. 27, 2014

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Nov. 21, 2013

Feb. 27, 2014

Dec. 31, 2013

USD ($)

USD ($)

CHF

USD ($)

CHF

USD ($)

CHF

General Purpose

Issuance of Debt

Employee Benefit Plans

November 2013 Stock Repurchase Plan [Member]

November 2013 Stock Repurchase Plan [Member]

November 2013 Stock Repurchase Plan [Member]

USD ($)

USD ($)

USD ($)

Stockholders' Equity Note [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

Dividend installments

'

$0.51

'

'

'

'

'

'

'

'

'

'

'

Common shares in treasury, shares

'

3,038,477

3,038,477

2,510,878

2,510,878

5,905,136

5,905,136

'

'

'

'

'

'

Conditional Share Issuance, by Scenario [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Repurchase of outstanding common shares, shares

3,437,082

3,266,531

3,266,531

100,000

100,000

2,058,860

2,058,860

'

'

'

'

'

'

Cost of shares acquired

$326,000,000

$290,000,000

'

$7,000,000

'

$132,000,000

'

'

'

'

'

'

'

Authorized share capital for general purposes

'

'

'

'

'

'

'

140,000,000

33,000,000

25,410,929

'

'

'

Stock repurchase program authorized amount

'

'

'

'

'

'

'

'

'

'

2,000,000,000

'

'

Share repurchase authorization remaining

'

'

'

'

'

'

'

'

'

'

'

$1,620,000,000

$1,940,000,000

The number of votes associated with one Common Share

'

1

1

'

'

'

'

'

'

'

'

'

'

The maximum ownership percentage for voting allowed for any one shareholder

'

10.00%

10.00%

'

'

'

'

'

'

'

'

'

'

Par value reduction per common share

'

'

'

'

1.38

'

'

'

'

'

'

'

'

Dividends declared per common share

'

$2.02

1.85

$2.06

1.91

$1.38

1.22

'

'

'

'

'

'

Shareholders_equity_Rollforwar

Shareholders' equity (Rollforward Of Changes In Common Stock Shares Issued And Outstanding) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Changes In Common Stock Shares Issues And Outstanding [Roll Forward]	'	'	'
Shares issued, beginning of year	342,832,412	342,832,412	341,094,559
Exercise of stock options	0	0	1,737,853
Shares issued, end of year	342,832,412	342,832,412	342,832,412
Common Shares in treasury, end of year	-3,038,477	-2,510,878	-5,905,136
Shares issued and outstanding, end of year	339,793,935	340,321,534	336,927,276
Balance, beginning of year	-9,467	-9,467	-101,481
Shares redeemed	0	0	92,014
Balance, end of year	-9,467	-9,467	-9,467

Sharebased_compensation_Narrat

Share-based compensation (Narrative) (Detail) (USD $)

12 Months Ended

12 Months Ended

In Millions, except Share data, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2004

Stock options

Restricted stock

Restricted stock

Restricted stock

Restricted stock

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

ACE Limited 2004 Long-Term Incentive Plan

Common shares

Common shares

Restricted stock

ACE Limited 2004 Long-Term Incentive Plan

ACE Limited 2004 Long-Term Incentive Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common shares authorized for issuance under plan

'

'

'

'

'

'

'

'

'

'

'

'

'

38,600,000

Vesting period of award

'

'

'

'3 years

'

'

'

'

'

'

'

'4 years

'

'

Common shares remaining as available for issuance under the ESPP

'

'

'

'

'

'

'

'

'

'

'

'

11,231,423

'

Unrecognized compensation expense related to the unvested share-based awards

$107

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted-average expected recognition period for the unrecognized compensation expense

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock option term in years

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

Weighted average remaining contractual term for stock options outstanding

'6 years 6 months 6 days

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted-average remaining contractual term for stock options exercisable

'4 years 9 months 12 days

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash received from exercise of stock options

85

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted stock awards granted to non-management directors

20,969

25,669

32,660

'

'

'

'

'

'

'

'

'

'

'

Restricted stock units awarded to employees and officers of ACE and subsidiaries during period

'

'

'

'

1,544,485

1,589,178

1,808,745

'

271,004

262,549

261,214

'

'

'

Weighted average grant-day fair value of restricted stock units granted to employees and officers of the company (US$ per share)

'

'

'

'

$86.07

$73.46

$60.01

'

$85.44

$73.41

$62.85

'

'

'

Number of unvested restricted stock units outstanding

'

'

'

'

3,708,187

4,254,847

4,851,490

5,305,732

617,893

'

'

'

'

'

Number of deferred restricted stock units

'

'

'

'

'

'

'

'

196,622

'

'

'

'

'

Amounts paid during period by employees for the purchase of shares under the ESPP

$14

$13

$12

'

'

'

'

'

'

'

'

'

'

'

Number of shares purchased during period by employees pursuant to the provisions of the ESPP

175,437

198,244

205,812

'

'

'

'

'

'

'

'

'

'

'

Sharebased_compensation_Pretax

Share-based compensation (Pre-tax and After-tax Share-based Compensation Expense) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restricted stock	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Share-based compensation expense, pre-tax	$153	$109	$108
Share-based compensation expense, after-tax	89	64	70
Stock options	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Share-based compensation expense, pre-tax	24	22	23
Share-based compensation expense, after-tax	18	17	17
Additional Paid-in Capital	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Excess Tax Benefit (Tax Deficiency) from Share-based Compensation, Financing Activities	$36	$18	$6

Sharebased_compensation_Weight

Share-based compensation (Weighted Average Assumptions for Option Grants) (Details) (Options)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Options	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Dividend yield	2.40%	2.70%	2.20%
Expected volatility	27.80%	29.80%	28.80%
Risk-free interest rate	1.00%	1.10%	2.30%
Expected life	'5 years 9 months 18 days	'5 years 9 months 18 days	'5 years 4 months 24 days

Sharebased_compensation_Rollfo

Share-based compensation (Rollforward Of Company's Stock Options) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Number of Options [Roll Forward]	'	'	'
Number of option outstanding, beginning of period	9,449,659	10,579,507	11,942,893
Number of options granted	1,821,063	1,462,103	1,649,824
Number of options exercised	-1,658,671	-2,401,869	-2,741,238
Number of options forfeited	-115,195	-190,082	-271,972
Number of option outstanding, end of period	9,496,856	9,449,659	10,579,507
Number of options exercisable, December 31, 2012	6,330,456	'	'
Weighted-Average Exercise Price [Roll Forward]	'	'	'
Weighted-average exercise price of options outstanding, beginning of period (US$ oer share)	$55.03	$49.78	$46.80
Weighted-average exercise price of options granted (US$ per share)	$85.41	$73.36	$62.68
Weighted-average exercise price of options exercised (US$ per share)	$48.17	$42.50	$44.45
Weighted average exercise price of options forfeited (US$ per share)	$72.50	$61.87	$51.33
Weighted-average exercise price of options outstanding, end of period (US$ oer share	$61.84	$55.03	$49.78
Weighted average exercise price of options exercisable, December 31, 2012 (US$ per share)	$53.52	'	'
Options, Weighted-Average Fair Value and Total Intrinsic Value [Abstract]	'	'	'
Weighted-average fair value of stock options granted (US$ per share)	$17.29	$15.58	$14.67
Total intrinsic value of options exercised	$70	$78	$63
Total intrinsic value of options outstanding	396	'	'
Total intrinsic value of options exercisable, December 31, 2012	$317	'	'

Sharebased_compensation_Rollfo1

Share-based compensation (Rollforward Of Company's Restricted Stock) (Details) (Restricted stock, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restricted stock	'	'	'
Number of Restricted Stock [Roll Forward]	'	'	'
Number of unvested restricted stock, beginning of period	4,254,847	4,851,490	5,305,732
Number of restricted stock, granted	1,544,485	1,589,178	1,808,745
Number of restricted stock, vested and issued	-1,951,494	-1,923,385	-1,929,189
Number of restricted stock, forfeited	-139,651	-262,436	-333,798
Number of unvested restricted stock, end of period	3,708,187	4,254,847	4,851,490
Weighted-Average Grant-Day Fair Value [Roll Forward]	'	'	'
Weighted average grant-day fair value of unvested restricted stock outstanding, beginning of period (US$ per share)	$59.53	$52.20	$48.74
Weighted average grant-day fair value of restricted stock, granted (US$ per share)	$86.07	$73.46	$60.01
Weighted average grant-day fair value of restricted stock, vested and issued (US$ per share)	$57.44	$52.71	$50.82
Weighted average grant-day fair value of restricted stock, forfeited (US$ per share)	$67.72	$58.40	$47.46
Weighted average grant-day fair value of unvested restricted stock outstanding, end of period (US$ per share)	$71.38	$59.53	$52.20

Pension_plans_Narrative_Detail

Pension plans (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Compensation and Retirement Disclosure [Abstract]	'	'	'
Expenses recognized during period under the defined contributions plans	$111	$99	$96
Fair value of plan assets	566	487	'
Projected benefit obligation	591	531	'
Accrued pension liability	25	44	'
Defined pension plan contribution expected for 2014	3	'	'
Estimated net actuarial loss expected to be amortized from AOCI	3	'	'
Benefit payments made during period	26	37	'
Benefit payments for settlement of a defined benefit plan	'	$12	'

Pension_plans_Schedule_of_Expe

Pension plans (Schedule of Expected Future Benefit Payments) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Compensation and Retirement Disclosure [Abstract]	'
2014	$19
2015	22
2016	23
2017	22
2018	23
2019-2023	$129

Other_income_expense_Details

Other (income) expense (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Other Income and Expenses [Abstract]	'	'	'
Amortization of Intangible Assets	$95	$51	$29
Equity in net (income) loss of partially-owned entities	-119	-80	-32
(Gains) losses from fair value changes in separate account assets	-16	-29	36
Federal excise and capital taxes	24	22	20
Acquisition-related costs	4	11	5
Other	27	19	23
Other (income) expense	$15	($6)	$81

Segment_Information_Operations

Segment Information (Operations By Segment) (Detail) (USD $)	3 Months Ended								12 Months Ended
	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
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums written	'	'	'	'	'	'	'	'	$17,025,000,000	$16,075,000,000	$15,372,000,000
Net premiums earned	4,363,000,000	4,610,000,000	4,067,000,000	3,573,000,000	3,848,000,000	4,665,000,000	3,783,000,000	3,381,000,000	16,613,000,000	15,677,000,000	15,387,000,000
Losses and loss expenses	2,517,000,000	2,655,000,000	2,250,000,000	1,926,000,000	2,683,000,000	3,047,000,000	2,119,000,000	1,804,000,000	9,348,000,000	9,653,000,000	9,520,000,000
Policy benefits	136,000,000	138,000,000	110,000,000	131,000,000	142,000,000	130,000,000	102,000,000	147,000,000	515,000,000	521,000,000	401,000,000
Policy acquisition costs	'	'	'	'	'	'	'	'	2,659,000,000	2,446,000,000	2,472,000,000
Administrative expenses	'	'	'	'	'	'	'	'	2,211,000,000	2,096,000,000	2,068,000,000
Underwriting income (loss)	'	'	'	'	'	'	'	'	1,880,000,000	961,000,000	926,000,000
Net investment income	557,000,000	522,000,000	534,000,000	531,000,000	567,000,000	533,000,000	537,000,000	544,000,000	2,144,000,000	2,181,000,000	2,242,000,000
Net realized gains (losses) including OTTI	154,000,000	40,000,000	104,000,000	206,000,000	272,000,000	-60,000,000	-394,000,000	260,000,000	504,000,000	78,000,000	-795,000,000
Interest expense	'	'	'	'	'	'	'	'	275,000,000	250,000,000	250,000,000
Other (income) expense	'	'	'	'	'	'	'	'	15,000,000	-6,000,000	81,000,000
(Gains) losses from fair value changes in separate account assets	'	'	'	'	'	'	'	'	-16,000,000	-29,000,000	36,000,000
Other	'	'	'	'	'	'	'	'	31,000,000	23,000,000	45,000,000
Income tax expense (benefit)	'	'	'	'	'	'	'	'	480,000,000	270,000,000	502,000,000
Net income (loss)	998,000,000	916,000,000	891,000,000	953,000,000	765,000,000	640,000,000	328,000,000	973,000,000	3,758,000,000	2,706,000,000	1,540,000,000
Insurance - North American Agriculture	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums written	'	'	'	'	'	'	'	'	1,627,000,000	1,859,000,000	1,951,000,000
Net premiums earned	'	'	'	'	'	'	'	'	1,678,000,000	1,872,000,000	1,942,000,000
Losses and loss expenses	'	'	'	'	'	'	'	'	1,524,000,000	1,911,000,000	1,699,000,000
Policy benefits	'	'	'	'	'	'	'	'	0	0	'
Policy acquisition costs	'	'	'	'	'	'	'	'	53,000,000	28,000,000	80,000,000
Administrative expenses	'	'	'	'	'	'	'	'	11,000,000	-7,000,000	-6,000,000
Underwriting income (loss)	'	'	'	'	'	'	'	'	90,000,000	-60,000,000	169,000,000
Net investment income	'	'	'	'	'	'	'	'	26,000,000	25,000,000	22,000,000
Net realized gains (losses) including OTTI	'	'	'	'	'	'	'	'	1,000,000	1,000,000	6,000,000
Interest expense	'	'	'	'	'	'	'	'	1,000,000	0	2,000,000
(Gains) losses from fair value changes in separate account assets	'	'	'	'	'	'	'	'	0	0	0
Other	'	'	'	'	'	'	'	'	32,000,000	32,000,000	18,000,000
Income tax expense (benefit)	'	'	'	'	'	'	'	'	20,000,000	-29,000,000	51,000,000
Net income (loss)	'	'	'	'	'	'	'	'	64,000,000	-37,000,000	126,000,000
Insurance - Overseas General	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums written	'	'	'	'	'	'	'	'	6,520,000,000	5,863,000,000	5,629,000,000
Net premiums earned	'	'	'	'	'	'	'	'	6,333,000,000	5,740,000,000	5,614,000,000
Losses and loss expenses	'	'	'	'	'	'	'	'	3,062,000,000	2,862,000,000	3,029,000,000
Policy benefits	'	'	'	'	'	'	'	'	'	'	'
Policy acquisition costs	'	'	'	'	'	'	'	'	1,453,000,000	1,353,000,000	1,335,000,000
Administrative expenses	'	'	'	'	'	'	'	'	1,008,000,000	935,000,000	939,000,000
Underwriting income (loss)	'	'	'	'	'	'	'	'	810,000,000	590,000,000	311,000,000
Net investment income	'	'	'	'	'	'	'	'	539,000,000	521,000,000	546,000,000
Net realized gains (losses) including OTTI	'	'	'	'	'	'	'	'	18,000,000	103,000,000	-33,000,000
Interest expense	'	'	'	'	'	'	'	'	5,000,000	5,000,000	5,000,000
(Gains) losses from fair value changes in separate account assets	'	'	'	'	'	'	'	'	'	'	'
Other	'	'	'	'	'	'	'	'	39,000,000	3,000,000	0
Income tax expense (benefit)	'	'	'	'	'	'	'	'	222,000,000	133,000,000	164,000,000
Net income (loss)	'	'	'	'	'	'	'	'	1,101,000,000	1,073,000,000	721,000,000
Global Reinsurance	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums written	'	'	'	'	'	'	'	'	991,000,000	1,025,000,000	979,000,000
Net premiums earned	'	'	'	'	'	'	'	'	976,000,000	1,002,000,000	1,003,000,000
Losses and loss expenses	'	'	'	'	'	'	'	'	396,000,000	553,000,000	621,000,000
Policy benefits	'	'	'	'	'	'	'	'	'	'	'
Policy acquisition costs	'	'	'	'	'	'	'	'	'	'	185,000,000
Administrative expenses	'	'	'	'	'	'	'	'	50,000,000	51,000,000	52,000,000
Underwriting income (loss)	'	'	'	'	'	'	'	'	333,000,000	226,000,000	145,000,000
Net investment income	'	'	'	'	'	'	'	'	280,000,000	290,000,000	287,000,000
Net realized gains (losses) including OTTI	'	'	'	'	'	'	'	'	53,000,000	6,000,000	-50,000,000
Interest expense	'	'	'	'	'	'	'	'	5,000,000	4,000,000	2,000,000
(Gains) losses from fair value changes in separate account assets	'	'	'	'	'	'	'	'	'	'	'
Other	'	'	'	'	'	'	'	'	-19,000,000	-15,000,000	-1,000,000
Income tax expense (benefit)	'	'	'	'	'	'	'	'	36,000,000	15,000,000	30,000,000
Net income (loss)	'	'	'	'	'	'	'	'	644,000,000	518,000,000	351,000,000
Life	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums written	'	'	'	'	'	'	'	'	1,972,000,000	1,979,000,000	1,913,000,000
Net premiums earned	'	'	'	'	'	'	'	'	1,905,000,000	1,916,000,000	1,859,000,000
Losses and loss expenses	'	'	'	'	'	'	'	'	582,000,000	611,000,000	593,000,000
Policy benefits	'	'	'	'	'	'	'	'	515,000,000	521,000,000	401,000,000
Policy acquisition costs	'	'	'	'	'	'	'	'	358,000,000	334,000,000	339,000,000
Administrative expenses	'	'	'	'	'	'	'	'	343,000,000	328,000,000	317,000,000
Underwriting income (loss)	'	'	'	'	'	'	'	'	107,000,000	122,000,000	209,000,000
Net investment income	'	'	'	'	'	'	'	'	251,000,000	251,000,000	226,000,000
Net realized gains (losses) including OTTI	'	'	'	'	'	'	'	'	360,000,000	-72,000,000	806,000,000
Interest expense	'	'	'	'	'	'	'	'	15,000,000	12,000,000	11,000,000
(Gains) losses from fair value changes in separate account assets	'	'	'	'	'	'	'	'	16,000,000	29,000,000	-36,000,000
Other	'	'	'	'	'	'	'	'	13,000,000	25,000,000	26,000,000
Income tax expense (benefit)	'	'	'	'	'	'	'	'	34,000,000	58,000,000	50,000,000
Net income (loss)	'	'	'	'	'	'	'	'	672,000,000	235,000,000	-494,000,000
Corporate and Other	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums written	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	'	'	'
Losses and loss expenses	'	'	'	'	'	'	'	'	8,000,000	1,000,000	1,000,000
Policy benefits	'	'	'	'	'	'	'	'	'	'	'
Policy acquisition costs	'	'	'	'	'	'	'	'	1,000,000	1,000,000	1,000,000
Administrative expenses	'	'	'	'	'	'	'	'	198,000,000	181,000,000	168,000,000
Underwriting income (loss)	'	'	'	'	'	'	'	'	-207,000,000	-183,000,000	-170,000,000
Net investment income	'	'	'	'	'	'	'	'	27,000,000	28,000,000	13,000,000
Net realized gains (losses) including OTTI	'	'	'	'	'	'	'	'	0	-1,000,000	6,000,000
Interest expense	'	'	'	'	'	'	'	'	244,000,000	217,000,000	217,000,000
(Gains) losses from fair value changes in separate account assets	'	'	'	'	'	'	'	'	'	'	'
Other	'	'	'	'	'	'	'	'	24,000,000	19,000,000	15,000,000
Income tax expense (benefit)	'	'	'	'	'	'	'	'	-179,000,000	-136,000,000	-137,000,000
Net income (loss)	'	'	'	'	'	'	'	'	-269,000,000	-256,000,000	-258,000,000
Insurance - North American P&C	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums written	'	'	'	'	'	'	'	'	5,915,000,000	5,349,000,000	4,900,000,000
Net premiums earned	'	'	'	'	'	'	'	'	5,721,000,000	5,147,000,000	4,969,000,000
Losses and loss expenses	'	'	'	'	'	'	'	'	3,776,000,000	3,715,000,000	3,577,000,000
Policy benefits	'	'	'	'	'	'	'	'	0	0	'
Policy acquisition costs	'	'	'	'	'	'	'	'	597,000,000	558,000,000	532,000,000
Administrative expenses	'	'	'	'	'	'	'	'	601,000,000	608,000,000	598,000,000
Underwriting income (loss)	'	'	'	'	'	'	'	'	747,000,000	266,000,000	262,000,000
Net investment income	'	'	'	'	'	'	'	'	1,021,000,000	1,066,000,000	1,148,000,000
Net realized gains (losses) including OTTI	'	'	'	'	'	'	'	'	72,000,000	41,000,000	28,000,000
Interest expense	'	'	'	'	'	'	'	'	5,000,000	12,000,000	13,000,000
(Gains) losses from fair value changes in separate account assets	'	'	'	'	'	'	'	'	0	0	0
Other	'	'	'	'	'	'	'	'	-58,000,000	-41,000,000	-13,000,000
Income tax expense (benefit)	'	'	'	'	'	'	'	'	347,000,000	229,000,000	344,000,000
Net income (loss)	'	'	'	'	'	'	'	'	$1,546,000,000	$1,173,000,000	$1,094,000,000

Segment_Information_Net_Premiu

Segment Information (Net Premiums Earned For Segment By Product) (Detail) (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
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Property & All Other	'	'	'	'	'	'	'	'	$6,382	$5,973	$5,712
Casualty	'	'	'	'	'	'	'	'	5,759	5,292	5,340
Life, Accident & Health	'	'	'	'	'	'	'	'	4,472	4,412	4,335
Net premiums earned	4,363	4,610	4,067	3,573	3,848	4,665	3,783	3,381	16,613	15,677	15,387
Insurance - North American P&C	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Property & All Other	'	'	'	'	'	'	'	'	1,489	1,370	1,232
Casualty	'	'	'	'	'	'	'	'	3,847	3,406	3,380
Life, Accident & Health	'	'	'	'	'	'	'	'	385	371	357
Net premiums earned	'	'	'	'	'	'	'	'	5,721	5,147	4,969
Insurance - North American Agriculture	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Property & All Other	'	'	'	'	'	'	'	'	1,678	1,872	1,942
Casualty	'	'	'	'	'	'	'	'	'	'	0
Life, Accident & Health	'	'	'	'	'	'	'	'	'	'	0
Net premiums earned	'	'	'	'	'	'	'	'	1,678	1,872	1,942
Insurance - Overseas General	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Property & All Other	'	'	'	'	'	'	'	'	2,672	2,236	2,080
Casualty	'	'	'	'	'	'	'	'	1,479	1,379	1,415
Life, Accident & Health	'	'	'	'	'	'	'	'	2,182	2,125	2,119
Net premiums earned	'	'	'	'	'	'	'	'	6,333	5,740	5,614
Global Reinsurance	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Property & All Other	'	'	'	'	'	'	'	'	543	495	458
Casualty	'	'	'	'	'	'	'	'	433	507	545
Life, Accident & Health	'	'	'	'	'	'	'	'	'	'	0
Net premiums earned	'	'	'	'	'	'	'	'	976	1,002	1,003
Life	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Property & All Other	'	'	'	'	'	'	'	'	'	'	0
Casualty	'	'	'	'	'	'	'	'	'	'	0
Life, Accident & Health	'	'	'	'	'	'	'	'	1,905	1,916	1,859
Net premiums earned	'	'	'	'	'	'	'	'	$1,905	$1,916	$1,859

Segment_Information_Net_Premiu1

Segment Information (Net Premiums Earned By Geographic Region) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]	'	'	'
Net Premiums Earned by Geographic Region	'Years Ended	'	'
North America	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Percentage of net premiums earned by geographic region	58.00%	60.00%	61.00%
Europe	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Percentage of net premiums earned by geographic region	17.00%	17.00%	18.00%
Asia Pacific / Far East	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Percentage of net premiums earned by geographic region	16.00%	16.00%	14.00%
Latin America	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Percentage of net premiums earned by geographic region	9.00%	7.00%	7.00%

Earnings_Per_Share_Detail

Earnings Per Share (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, except 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
Earnings Per Share [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Net income	$998	$916	$891	$953	$765	$640	$328	$973	$3,758	$2,706	$1,540
Weighted-average shares outstanding	'	'	'	'	'	'	'	'	340,906,490	339,843,438	338,159,409
Share-based compensation plans	'	'	'	'	'	'	'	'	3,241,085	2,903,512	2,620,815
Adjusted weighted-average shares outstanding and assumed conversions	'	'	'	'	'	'	'	'	344,147,575	342,746,950	340,780,224
Basic earnings per share	$2.93	$2.68	$2.61	$2.80	$2.24	$1.88	$0.96	$2.87	$11.02	$7.96	$4.55
Diluted earnings per share	$2.90	$2.66	$2.59	$2.77	$2.22	$1.86	$0.96	$2.84	$10.92	$7.89	$4.52
Potential anti-dilutive share conversions	'	'	'	'	'	'	'	'	1,031,297	896,591	111,326

Related_party_transaction_Deta

Related party transaction (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Related Party Transactions [Abstract]	'	'
ACE Foundation - Bermuda-Loan	$26	$27

Statutory_Financial_Informatio2

Statutory Financial Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statutory Accounting Practices [Line Items]	'	'	'
Dividends available to be paid	$3,800,000,000	'	'
Statutory capital and surplus	25,600,000,000	24,400,000,000	'
Statutory net income	3,700,000,000	2,900,000,000	1,900,000,000
Approximate increase in statutory capital and surplus resulting from discount of certain A&E liabilities	158,000,000	161,000,000	'
Statutory Accounting Practices, Statutory Capital and Surplus Required	$14,500,000,000	$14,300,000,000	'

Information_provided_in_connec2

Information provided in connection with outstanding debt of subsidiaries (Condensed Consolidating Balance Sheet) (Detail) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
In Millions, unless otherwise specified
Condensed Financial Statements, Captions [Line Items]	'		'		'		'
Investments	$60,928		$60,264		'		'
Cash	579		615		614	[1]	772
Insurance and reinsurance balances receivable	5,026		4,147		'		'
Reinsurance recoverable on losses and loss expenses	11,227		12,078		'		'
Reinsurance recoverable on policy benefits	218		241		'		'
Value of business acquired	536		614		'		'
Goodwill and other intangible assets	5,404		4,975		'		'
Investments in subsidiaries	'		'		'		'
Due from subsidiaries and affiliates, net	'		'		'		'
Other assets	10,592		9,611		'		'
Total assets	94,510		92,545		'		'
Unpaid losses and loss expenses	37,443		37,946		37,477		37,391
Unearned premiums	7,539		6,864		'		'
Future policy benefits	4,615		4,470		'		'
Due to subsidiaries and affiliates, net	'		'		'		'
Bank Overdrafts	'		0		'		'
Short-term debt	1,901		1,401		'		'
Long-term debt	3,807		3,360		'		'
Trust preferred securities	309		309		'		'
Other liabilities	10,071		10,664		'		'
Total liabilities	65,685		65,014		'		'
Total shareholders' equity	28,825		27,531		24,332		'
Total liabilities and shareholders’ equity	94,510		92,545		'		'
Scenario, Previously Reported	'		'		'		'
Condensed Financial Statements, Captions [Line Items]	'		'		'		'
Investments	'		60,264		'		'
Cash	'		615		614	[1],[2]	772	[2]
Insurance and reinsurance balances receivable	'		4,147		'		'
Reinsurance recoverable on losses and loss expenses	'		12,078		'		'
Reinsurance recoverable on policy benefits	'		241		'		'
Value of business acquired	'		614		'		'
Goodwill and other intangible assets	'		4,975		'		'
Investments in subsidiaries	'		'		'		'
Due from subsidiaries and affiliates, net	'		'		'		'
Other assets	'		9,611		'		'
Total assets	'		92,545		'		'
Unpaid losses and loss expenses	'		37,946		'		'
Unearned premiums	'		6,864		'		'
Future policy benefits	'		4,470		'		'
Due to subsidiaries and affiliates, net	'		'		'		'
Short-term debt	'		1,401		'		'
Long-term debt	'		3,360		'		'
Trust preferred securities	'		309		'		'
Other liabilities	'		10,664		'		'
Total liabilities	'		65,014		'		'
Total shareholders' equity	'		27,531		'		'
Total liabilities and shareholders’ equity	'		92,545		'		'
ACE limited (Parent Gurantor)	'		'		'		'
Condensed Financial Statements, Captions [Line Items]	'		'		'		'
Investments	32		31		'		'
Cash	0		103		106		308
Insurance and reinsurance balances receivable	'		'		'		'
Reinsurance recoverable on losses and loss expenses	'		'		'		'
Reinsurance recoverable on policy benefits	'		'		'		'
Value of business acquired	'		'		'		'
Goodwill and other intangible assets	'		'		'		'
Investments in subsidiaries	28,351		27,251		'		'
Due from subsidiaries and affiliates, net	844		204		'		'
Other assets	5		13		'		'
Total assets	29,232		27,602		'		'
Unpaid losses and loss expenses	'		'		'		'
Unearned premiums	'		'		'		'
Future policy benefits	'		'		'		'
Due to subsidiaries and affiliates, net	'		'		'		'
Bank Overdrafts	185		'		'		'
Short-term debt	'		'		'		'
Long-term debt	'		'		'		'
Trust preferred securities	'		'		'		'
Other liabilities	222		71		'		'
Total liabilities	407		71		'		'
Total shareholders' equity	28,825		27,531		'		'
Total liabilities and shareholders’ equity	29,232		27,602		'		'
ACE limited (Parent Gurantor) | Scenario, Previously Reported	'		'		'		'
Condensed Financial Statements, Captions [Line Items]	'		'		'		'
Investments	'		31		'		'
Cash	'		103		106		308
Insurance and reinsurance balances receivable	'		'		'		'
Reinsurance recoverable on losses and loss expenses	'		'		'		'
Reinsurance recoverable on policy benefits	'		'		'		'
Value of business acquired	'		'		'		'
Goodwill and other intangible assets	'		'		'		'
Investments in subsidiaries	'		27,251		'		'
Due from subsidiaries and affiliates, net	'		204		'		'
Other assets	'		13		'		'
Total assets	'		27,602		'		'
Unpaid losses and loss expenses	'		'		'		'
Unearned premiums	'		'		'		'
Future policy benefits	'		'		'		'
Due to subsidiaries and affiliates, net	'		'		'		'
Short-term debt	'		'		'		'
Long-term debt	'		'		'		'
Trust preferred securities	'		'		'		'
Other liabilities	'		71		'		'
Total liabilities	'		71		'		'
Total shareholders' equity	'		27,531		'		'
Total liabilities and shareholders’ equity	'		27,602		'		'
ACE INA Holdings Inc. (Subsidiary Issuer)	'		'		'		'
Condensed Financial Statements, Captions [Line Items]	'		'		'		'
Investments	10		14		'		'
Cash	16		2		5		33
Insurance and reinsurance balances receivable	'		'		'		'
Reinsurance recoverable on losses and loss expenses	'		'		'		'
Reinsurance recoverable on policy benefits	'		'		'		'
Value of business acquired	'		'		'		'
Goodwill and other intangible assets	'		'		'		'
Investments in subsidiaries	18,105		17,016		'		'
Due from subsidiaries and affiliates, net	'		'		'		'
Other assets	258		210		'		'
Total assets	18,389		17,242		'		'
Unpaid losses and loss expenses	'		'		'		'
Unearned premiums	'		'		'		'
Future policy benefits	'		'		'		'
Due to subsidiaries and affiliates, net	714		68		'		'
Bank Overdrafts	'		349		'		'
Short-term debt	500		'		'		'
Long-term debt	3,795		3,347		'		'
Trust preferred securities	309		309		'		'
Other liabilities	1,318		1,195		'		'
Total liabilities	6,636		5,268		'		'
Total shareholders' equity	11,753		11,974		'		'
Total liabilities and shareholders’ equity	18,389		17,242		'		'
ACE INA Holdings Inc. (Subsidiary Issuer) | Scenario, Previously Reported	'		'		'		'
Condensed Financial Statements, Captions [Line Items]	'		'		'		'
Investments	'		31,074		'		'
Cash	'		515		382		573
Insurance and reinsurance balances receivable	'		3,654		'		'
Reinsurance recoverable on losses and loss expenses	'		17,232		'		'
Reinsurance recoverable on policy benefits	'		1,187		'		'
Value of business acquired	'		610		'		'
Goodwill and other intangible assets	'		4,419		'		'
Investments in subsidiaries	'		'		'		'
Due from subsidiaries and affiliates, net	'		'		'		'
Other assets	'		7,563		'		'
Total assets	'		66,254		'		'
Unpaid losses and loss expenses	'		31,356		'		'
Unearned premiums	'		5,872		'		'
Future policy benefits	'		3,876		'		'
Due to subsidiaries and affiliates, net	'		384		'		'
Short-term debt	'		851		'		'
Long-term debt	'		3,360		'		'
Trust preferred securities	'		309		'		'
Other liabilities	'		8,272		'		'
Total liabilities	'		54,280		'		'
Total shareholders' equity	'		11,974		'		'
Total liabilities and shareholders’ equity	'		66,254		'		'
Other ACE Limited Subsidiaries and Eliminations	'		'		'		'
Condensed Financial Statements, Captions [Line Items]	'		'		'		'
Investments	60,886		60,219		'		'
Cash	748	[3]	859	[3],[4]	651	[4]	431
Insurance and reinsurance balances receivable	5,835		4,742		'		'
Reinsurance recoverable on losses and loss expenses	20,057		20,935		'		'
Reinsurance recoverable on policy benefits	1,215		1,229		'		'
Value of business acquired	536		614		'		'
Goodwill and other intangible assets	5,404		4,975		'		'
Investments in subsidiaries	'		'		'		'
Due from subsidiaries and affiliates, net	'		'		'		'
Other assets	13,788		11,304		'		'
Total assets	108,469		104,877		'		'
Unpaid losses and loss expenses	45,714		46,109		'		'
Unearned premiums	9,242		8,248		'		'
Future policy benefits	5,612		5,458		'		'
Due to subsidiaries and affiliates, net	130		136		'		'
Bank Overdrafts	'		'		'		'
Short-term debt	1,401		1,401		'		'
Long-term debt	12		13		'		'
Trust preferred securities	'		'		'		'
Other liabilities	11,655		11,219		'		'
Total liabilities	73,766		72,584		'		'
Total shareholders' equity	34,703		32,293		'		'
Total liabilities and shareholders’ equity	108,469		104,877		'		'
Other ACE Limited Subsidiaries and Eliminations | Scenario, Previously Reported	'		'		'		'
Condensed Financial Statements, Captions [Line Items]	'		'		'		'
Investments	'		29,159		'		'
Cash	'		-3	[4]	126		-109
Insurance and reinsurance balances receivable	'		493		'		'
Reinsurance recoverable on losses and loss expenses	'		-5,154		'		'
Reinsurance recoverable on policy benefits	'		-946		'		'
Value of business acquired	'		4		'		'
Goodwill and other intangible assets	'		556		'		'
Investments in subsidiaries	'		'		'		'
Due from subsidiaries and affiliates, net	'		'		'		'
Other assets	'		2,035		'		'
Total assets	'		26,144		'		'
Unpaid losses and loss expenses	'		6,590		'		'
Unearned premiums	'		992		'		'
Future policy benefits	'		594		'		'
Due to subsidiaries and affiliates, net	'		-180		'		'
Short-term debt	'		550		'		'
Long-term debt	'		'		'		'
Trust preferred securities	'		'		'		'
Other liabilities	'		2,321		'		'
Total liabilities	'		10,867		'		'
Total shareholders' equity	'		15,277		'		'
Total liabilities and shareholders’ equity	'		26,144		'		'
Consolidating Adjustments	'		'		'		'
Condensed Financial Statements, Captions [Line Items]	'		'		'		'
Investments	'		'		'		'
Cash	-185		-349	[5]	-148	[5]	0
Insurance and reinsurance balances receivable	-809		-595		'		'
Reinsurance recoverable on losses and loss expenses	-8,830		-8,857		'		'
Reinsurance recoverable on policy benefits	-997		-988		'		'
Value of business acquired	'		'		'		'
Goodwill and other intangible assets	'		'		'		'
Investments in subsidiaries	-46,456		-44,267		'		'
Due from subsidiaries and affiliates, net	-844		-204		'		'
Other assets	-3,459		-1,916		'		'
Total assets	-61,580		-57,176		'		'
Unpaid losses and loss expenses	-8,271		-8,163		'		'
Unearned premiums	-1,703		-1,384		'		'
Future policy benefits	-997		-988		'		'
Due to subsidiaries and affiliates, net	-844		-204		'		'
Bank Overdrafts	-185		-349		'		'
Short-term debt	'		'		'		'
Long-term debt	'		'		'		'
Trust preferred securities	'		'		'		'
Other liabilities	-3,124		-1,821		'		'
Total liabilities	-15,124		-12,909		'		'
Total shareholders' equity	-46,456		-44,267		'		'
Total liabilities and shareholders’ equity	-61,580		-57,176		'		'
Consolidating Adjustments | Scenario, Previously Reported	'		'		'		'
Condensed Financial Statements, Captions [Line Items]	'		'		'		'
Investments	'		'		'		'
Cash	'		'	[5]	0		0
Insurance and reinsurance balances receivable	'		'		'		'
Reinsurance recoverable on losses and loss expenses	'		'		'		'
Reinsurance recoverable on policy benefits	'		'		'		'
Value of business acquired	'		'		'		'
Goodwill and other intangible assets	'		'		'		'
Investments in subsidiaries	'		-27,251		'		'
Due from subsidiaries and affiliates, net	'		-204		'		'
Other assets	'		'		'		'
Total assets	'		-27,455		'		'
Unpaid losses and loss expenses	'		'		'		'
Unearned premiums	'		'		'		'
Future policy benefits	'		'		'		'
Due to subsidiaries and affiliates, net	'		-204		'		'
Short-term debt	'		'		'		'
Long-term debt	'		'		'		'
Trust preferred securities	'		'		'		'
Other liabilities	'		'		'		'
Total liabilities	'		-204		'		'
Total shareholders' equity	'		-27,251		'		'
Total liabilities and shareholders’ equity	'		($27,455)		'		'
[1]	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[2]	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2010, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[3]	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2013 and December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[4]	Includes all other subsidiaries of ACE Limited and intercompany eliminations.
[5]	Includes ACE Limited parent company eliminations and certain consolidating adjustments.

Information_provided_in_connec3

Information provided in connection with outstanding debt of subsidiaries (Condensed Consolidating Statement Of Operations and Comprehensive Income) (Detail) (USD $)

3 Months Ended

12 Months Ended

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

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

$17,025,000,000

$16,075,000,000

$15,372,000,000

Net premiums earned

4,363,000,000

4,610,000,000

4,067,000,000

3,573,000,000

3,848,000,000

4,665,000,000

3,783,000,000

3,381,000,000

16,613,000,000

15,677,000,000

15,387,000,000

Net investment income

557,000,000

522,000,000

534,000,000

531,000,000

567,000,000

533,000,000

537,000,000

544,000,000

2,144,000,000

2,181,000,000

2,242,000,000

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

'

'

'

Net realized gains (losses) including OTTI

154,000,000

40,000,000

104,000,000

206,000,000

272,000,000

-60,000,000

-394,000,000

260,000,000

504,000,000

78,000,000

-795,000,000

Losses and loss expenses

2,517,000,000

2,655,000,000

2,250,000,000

1,926,000,000

2,683,000,000

3,047,000,000

2,119,000,000

1,804,000,000

9,348,000,000

9,653,000,000

9,520,000,000

Policy benefits

136,000,000

138,000,000

110,000,000

131,000,000

142,000,000

130,000,000

102,000,000

147,000,000

515,000,000

521,000,000

401,000,000

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

4,870,000,000

4,542,000,000

4,540,000,000

Interest (income) expense

'

'

'

'

'

'

'

'

275,000,000

250,000,000

250,000,000

Other (income) expense

'

'

'

'

'

'

'

'

15,000,000

-6,000,000

81,000,000

Income tax expense

'

'

'

'

'

'

'

'

480,000,000

270,000,000

502,000,000

Net income (loss)

998,000,000

916,000,000

891,000,000

953,000,000

765,000,000

640,000,000

328,000,000

973,000,000

3,758,000,000

2,706,000,000

1,540,000,000

Comprehensive income

'

'

'

'

'

'

'

'

2,023,000,000

3,682,000,000

1,857,000,000

ACE limited (Parent Gurantor)

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

'

0

Net premiums earned

'

'

'

'

'

'

'

'

'

'

0

Net investment income

'

'

'

'

'

'

'

'

2,000,000

1,000,000

2,000,000

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

3,580,000,000

2,590,000,000

1,459,000,000

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

0

17,000,000

-4,000,000

Losses and loss expenses

'

'

'

'

'

'

'

'

'

'

0

Policy benefits

'

'

'

'

'

'

'

'

'

'

0

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

60,000,000

62,000,000

69,000,000

Interest (income) expense

'

'

'

'

'

'

'

'

-32,000,000

-33,000,000

37,000,000

Other (income) expense

'

'

'

'

'

'

'

'

-221,000,000

-137,000,000

125,000,000

Income tax expense

'

'

'

'

'

'

'

'

17,000,000

10,000,000

10,000,000

Net income (loss)

'

'

'

'

'

'

'

'

3,758,000,000

2,706,000,000

1,540,000,000

Comprehensive income

'

'

'

'

'

'

'

'

2,023,000,000

3,682,000,000

1,857,000,000

ACE INA Holdings Inc. (Subsidiary Issuer)

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

'

0

Net premiums earned

'

'

'

'

'

'

'

'

'

'

0

Net investment income

'

'

'

'

'

'

'

'

'

'

2,000,000

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

'

'

989,000,000

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

'

'

0

Losses and loss expenses

'

'

'

'

'

'

'

'

'

'

0

Policy benefits

'

'

'

'

'

'

'

'

'

'

0

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

'

'

37,000,000

Interest (income) expense

'

'

'

'

'

'

'

'

'

'

-266,000,000

Other (income) expense

'

'

'

'

'

'

'

'

'

'

-21,000,000

Income tax expense

'

'

'

'

'

'

'

'

'

'

-103,000,000

Net income (loss)

'

'

'

'

'

'

'

'

'

'

770,000,000

Comprehensive income

'

'

'

'

'

'

'

'

'

'

1,077,000,000

Other ACE Limited Subsidiaries and Eliminations

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

'

15,372,000,000

Net premiums earned

'

'

'

'

'

'

'

'

'

'

15,387,000,000

Net investment income

'

'

'

'

'

'

'

'

'

'

2,238,000,000

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

'

'

0

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

'

'

-791,000,000

Losses and loss expenses

'

'

'

'

'

'

'

'

'

'

9,520,000,000

Policy benefits

'

'

'

'

'

'

'

'

'

'

401,000,000

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

'

'

4,434,000,000

Interest (income) expense

'

'

'

'

'

'

'

'

'

'

-21,000,000

Other (income) expense

'

'

'

'

'

'

'

'

'

'

-185,000,000

Income tax expense

'

'

'

'

'

'

'

'

'

'

595,000,000

Net income (loss)

'

'

'

'

'

'

'

'

'

'

1,678,000,000

[1]

Comprehensive income

'

'

'

'

'

'

'

'

'

'

1,994,000,000

Consolidating Adjustments

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

'

0

Net premiums earned

'

'

'

'

'

'

'

'

'

'

0

Net investment income

'

'

'

'

'

'

'

'

'

'

0

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

-4,522,000,000

-3,501,000,000

-2,448,000,000

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

'

'

0

Losses and loss expenses

'

'

'

'

'

'

'

'

'

'

0

Policy benefits

'

'

'

'

'

'

'

'

'

'

0

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

'

'

0

Interest (income) expense

'

'

'

'

'

'

'

'

'

'

0

Other (income) expense

'

'

'

'

'

'

'

'

'

'

0

Income tax expense

'

'

'

'

'

'

'

'

'

'

0

Net income (loss)

'

'

'

'

'

'

'

'

-4,522,000,000

-3,501,000,000

-2,448,000,000

[2]

Comprehensive income

'

'

'

'

'

'

'

'

-1,821,000,000

-4,933,000,000

-3,071,000,000

ACE INA Holdings Inc. (Subsidiary Issuer)

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

'

'

Net premiums earned

'

'

'

'

'

'

'

'

'

'

'

Net investment income

'

'

'

'

'

'

'

'

3,000,000

3,000,000

'

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

942,000,000

911,000,000

'

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

-2,000,000

'

'

Losses and loss expenses

'

'

'

'

'

'

'

'

'

'

'

Policy benefits

'

'

'

'

'

'

'

'

'

'

'

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

19,000,000

28,000,000

'

Interest (income) expense

'

'

'

'

'

'

'

'

270,000,000

235,000,000

'

Other (income) expense

'

'

'

'

'

'

'

'

27,000,000

9,000,000

'

Income tax expense

'

'

'

'

'

'

'

'

-108,000,000

-110,000,000

'

Net income (loss)

'

'

'

'

'

'

'

'

735,000,000

752,000,000

'

Comprehensive income

'

'

'

'

'

'

'

'

-230,000,000

1,209,000,000

'

Other ACE Limited Subsidiaries and Eliminations

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

17,025,000,000

16,075,000,000

'

Net premiums earned

'

'

'

'

'

'

'

'

16,613,000,000

15,677,000,000

'

Net investment income

'

'

'

'

'

'

'

'

2,139,000,000

2,177,000,000

'

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

'

'

'

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

506,000,000

61,000,000

'

Losses and loss expenses

'

'

'

'

'

'

'

'

9,348,000,000

9,653,000,000

'

Policy benefits

'

'

'

'

'

'

'

'

515,000,000

521,000,000

'

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

4,791,000,000

4,452,000,000

'

Interest (income) expense

'

'

'

'

'

'

'

'

37,000,000

48,000,000

'

Other (income) expense

'

'

'

'

'

'

'

'

209,000,000

122,000,000

'

Income tax expense

'

'

'

'

'

'

'

'

571,000,000

370,000,000

'

Net income (loss)

'

'

'

'

'

'

'

'

3,787,000,000

2,749,000,000

'

Comprehensive income

'

'

'

'

'

'

'

'

2,051,000,000

3,724,000,000

'

Scenario, Previously Reported

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

16,075,000,000

15,372,000,000

Net premiums earned

'

'

'

'

'

'

'

'

'

15,677,000,000

15,387,000,000

Net investment income

'

'

'

'

'

'

'

'

'

2,181,000,000

2,242,000,000

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

'

'

'

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

'

78,000,000

-795,000,000

Losses and loss expenses

'

'

'

'

'

'

'

'

'

9,653,000,000

9,520,000,000

Policy benefits

'

'

'

'

'

'

'

'

'

521,000,000

401,000,000

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

'

4,542,000,000

4,540,000,000

Interest (income) expense

'

'

'

'

'

'

'

'

'

250,000,000

250,000,000

Other (income) expense

'

'

'

'

'

'

'

'

'

-6,000,000

81,000,000

Income tax expense

'

'

'

'

'

'

'

'

'

270,000,000

502,000,000

Net income (loss)

'

'

'

'

'

'

'

'

'

2,706,000,000

1,540,000,000

Comprehensive income

'

'

'

'

'

'

'

'

'

3,682,000,000

'

Scenario, Previously Reported | ACE limited (Parent Gurantor)

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

'

0

Net premiums earned

'

'

'

'

'

'

'

'

'

'

0

Net investment income

'

'

'

'

'

'

'

'

'

1,000,000

2,000,000

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

'

2,590,000,000

1,459,000,000

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

'

17,000,000

-4,000,000

Losses and loss expenses

'

'

'

'

'

'

'

'

'

'

0

Policy benefits

'

'

'

'

'

'

'

'

'

'

0

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

'

62,000,000

69,000,000

Interest (income) expense

'

'

'

'

'

'

'

'

'

-33,000,000

37,000,000

Other (income) expense

'

'

'

'

'

'

'

'

'

-137,000,000

125,000,000

Income tax expense

'

'

'

'

'

'

'

'

'

10,000,000

10,000,000

Net income (loss)

'

'

'

'

'

'

'

'

'

2,706,000,000

1,540,000,000

Comprehensive income

'

'

'

'

'

'

'

'

'

3,682,000,000

1,857,000,000

Scenario, Previously Reported | ACE INA Holdings Inc. (Subsidiary Issuer)

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

'

9,081,000,000

Net premiums earned

'

'

'

'

'

'

'

'

'

'

9,082,000,000

Net investment income

'

'

'

'

'

'

'

'

'

'

1,096,000,000

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

'

'

0

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

'

'

62,000,000

Losses and loss expenses

'

'

'

'

'

'

'

'

'

'

5,889,000,000

Policy benefits

'

'

'

'

'

'

'

'

'

'

192,000,000

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

'

'

2,561,000,000

Interest (income) expense

'

'

'

'

'

'

'

'

'

'

-267,000,000

Other (income) expense

'

'

'

'

'

'

'

'

'

'

-143,000,000

Income tax expense

'

'

'

'

'

'

'

'

'

'

418,000,000

Net income (loss)

'

'

'

'

'

'

'

'

'

'

770,000,000

Comprehensive income

'

'

'

'

'

'

'

'

'

'

1,077,000,000

Scenario, Previously Reported | Other ACE Limited Subsidiaries and Eliminations

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

'

6,291,000,000

Net premiums earned

'

'

'

'

'

'

'

'

'

'

6,305,000,000

Net investment income

'

'

'

'

'

'

'

'

'

'

1,144,000,000

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

'

'

0

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

'

'

-853,000,000

Losses and loss expenses

'

'

'

'

'

'

'

'

'

'

3,631,000,000

Policy benefits

'

'

'

'

'

'

'

'

'

'

209,000,000

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

'

'

1,910,000,000

Interest (income) expense

'

'

'

'

'

'

'

'

'

'

-20,000,000

Other (income) expense

'

'

'

'

'

'

'

'

'

'

-63,000,000

Income tax expense

'

'

'

'

'

'

'

'

'

'

74,000,000

Net income (loss)

'

'

'

'

'

'

'

'

'

'

689,000,000

[1]

Comprehensive income

'

'

'

'

'

'

'

'

'

'

382,000,000

Scenario, Previously Reported | Consolidating Adjustments

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

'

0

Net premiums earned

'

'

'

'

'

'

'

'

'

'

0

Net investment income

'

'

'

'

'

'

'

'

'

'

0

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

'

-2,590,000,000

-1,459,000,000

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

'

'

0

Losses and loss expenses

'

'

'

'

'

'

'

'

'

'

0

Policy benefits

'

'

'

'

'

'

'

'

'

'

0

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

'

'

0

Interest (income) expense

'

'

'

'

'

'

'

'

'

'

0

Other (income) expense

'

'

'

'

'

'

'

'

'

'

0

Income tax expense

'

'

'

'

'

'

'

'

'

'

0

Net income (loss)

'

'

'

'

'

'

'

'

'

-2,590,000,000

-1,459,000,000

[2]

Comprehensive income

'

'

'

'

'

'

'

'

'

-2,590,000,000

-1,459,000,000

Scenario, Previously Reported | ACE INA Holdings Inc. (Subsidiary Issuer)

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

9,466,000,000

'

Net premiums earned

'

'

'

'

'

'

'

'

'

9,194,000,000

'

Net investment income

'

'

'

'

'

'

'

'

'

1,048,000,000

'

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

'

'

'

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

'

121,000,000

'

Losses and loss expenses

'

'

'

'

'

'

'

'

'

6,211,000,000

'

Policy benefits

'

'

'

'

'

'

'

'

'

309,000,000

'

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

'

2,564,000,000

'

Interest (income) expense

'

'

'

'

'

'

'

'

'

257,000,000

'

Other (income) expense

'

'

'

'

'

'

'

'

'

77,000,000

'

Income tax expense

'

'

'

'

'

'

'

'

'

193,000,000

'

Net income (loss)

'

'

'

'

'

'

'

'

'

752,000,000

'

Comprehensive income

'

'

'

'

'

'

'

'

'

1,209,000,000

'

Scenario, Previously Reported | Other ACE Limited Subsidiaries and Eliminations

'

'

'

'

'

'

'

'

'

'

'

Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Net premiums written

'

'

'

'

'

'

'

'

'

6,609,000,000

'

Net premiums earned

'

'

'

'

'

'

'

'

'

6,483,000,000

'

Net investment income

'

'

'

'

'

'

'

'

'

1,132,000,000

'

Equity in earnings of subsidiaries

'

'

'

'

'

'

'

'

'

'

'

Net realized gains (losses) including OTTI

'

'

'

'

'

'

'

'

'

-60,000,000

'

Losses and loss expenses

'

'

'

'

'

'

'

'

'

3,442,000,000

'

Policy benefits

'

'

'

'

'

'

'

'

'

212,000,000

'

Policy acquisition costs and administrative expenses

'

'

'

'

'

'

'

'

'

1,916,000,000

'

Interest (income) expense

'

'

'

'

'

'

'

'

'

26,000,000

'

Other (income) expense

'

'

'

'

'

'

'

'

'

54,000,000

'

Income tax expense

'

'

'

'

'

'

'

'

'

67,000,000

'

Net income (loss)

'

'

'

'

'

'

'

'

'

1,838,000,000

'

Comprehensive income

'

'

'

'

'

'

'

'

'

$1,381,000,000

'

[1]

Includes all other subsidiaries of ACE Limited and intercompany eliminations.

[2]

Includes ACE Limited parent company eliminations.

Information_provided_in_connec4

Information provided in connection with outstanding debt of subsidiaries (Condensed Consolidating Statement Of Cash Flows) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]	'		'		'
Net cash flows from operating activities	$4,022		$3,995		$3,470
Purchases of fixed maturities available for sale	-21,398		-23,961		-24,278
Purchases of fixed maturities held to maturity	-447		-388		-340
Purchases of equity securities	-264		-135		-309
Sales of fixed maturities available for sale	10,413		14,769		17,971
Sales of equity securities	142		119		376
Maturities and redemptions of fixed maturities available for sale	6,941		5,523		3,720
Maturities and redemptions of fixed maturities held to maturity	1,488		1,451		1,279
Net change in short-term investments	524		117		-300
Net derivative instruments settlements	-471		-281		-67
Advances from (to) affiliates	'		-206		28
Acquisition of subsidiaries (net of cash acquired)	-977		-98		-606
Capital contribution to subsidiary	'		0		0
Other	-393		-555		-482
Net cash flows used for investing activities	-4,442		-3,439		-3,036
Dividends paid on Common Shares	-517		-815		-459
Common Shares repurchased	-287		-11		-195
Net proceeds from (repayments) issuance of short-term debt	'		150		-50
Net proceeds from issuances of long-term debt	-947		'		'
Proceeds from share-based compensation plans	135		126		139
Advances from (to) affiliates	'		'		0
Capital contribution from subsidiary	'		0		0
Net proceeds from (payments to) affiliated notional cash pooling programs	'		'		0
Dividends to parent company	'		'		0
Other	113		'		'
Net cash flows from (used for) financing activities	391		-550		-565
Effect of foreign currency rate changes on cash and cash equivalents	-7		-5		-27
Net increase (decrease) in cash	-36		1		-158
Cash – beginning of year	615		614	[1]	772
Cash – end of year	579		615		614	[1]
Scenario, Previously Reported	'		'		'
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]	'		'		'
Net cash flows from operating activities	'		3,995		3,470
Purchases of fixed maturities available for sale	'		-23,844		-24,578
Purchases of fixed maturities held to maturity	'		-388		-340
Purchases of equity securities	'		-135		-309
Sales of fixed maturities available for sale	'		14,769		17,971
Sales of equity securities	'		119		376
Maturities and redemptions of fixed maturities available for sale	'		5,523		3,720
Maturities and redemptions of fixed maturities held to maturity	'		1,451		1,279
Net derivative instruments settlements	'		-281		-67
Advances from (to) affiliates	'		'		'
Acquisition of subsidiaries (net of cash acquired)	'		-98		-606
Capital contribution to subsidiary	'		'		'
Other	'		-555		482
Net cash flows used for investing activities	'		-3,439		-3,036
Dividends paid on Common Shares	'		-815		-459
Common Shares repurchased	'		-11		195
Net proceeds from (repayments) issuance of short-term debt	'		150		-50
Proceeds from share-based compensation plans	'		126		139
Advances from (to) affiliates	'		'		'
Capital contribution from subsidiary	'		0		0
Dividends to parent company	'		'		'
Net cash flows from (used for) financing activities	'		-550		-565
Effect of foreign currency rate changes on cash and cash equivalents	'		-5		-27
Net increase (decrease) in cash	'		1		-158
Cash – beginning of year	'		614	[1],[2]	772	[2]
Cash – end of year	'		615		614	[1],[2]
ACE limited (Parent Gurantor)	'		'		'
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]	'		'		'
Net cash flows from operating activities	970		573		831
Purchases of fixed maturities available for sale	'		'		0
Purchases of fixed maturities held to maturity	'		'		0
Purchases of equity securities	'		'		0
Sales of fixed maturities available for sale	'		'		0
Sales of equity securities	'		'		0
Maturities and redemptions of fixed maturities available for sale	'		'		0
Maturities and redemptions of fixed maturities held to maturity	'		'		0
Net change in short-term investments	-1		0		9
Net derivative instruments settlements	0		-1		-3
Advances from (to) affiliates	621		'		'
Acquisition of subsidiaries (net of cash acquired)	'		'		0
Capital contribution to subsidiary	133		'		385
Other	'		'		0
Net cash flows used for investing activities	-134		-1		-379
Dividends paid on Common Shares	-517		-815		-459
Common Shares repurchased	'		'		0
Net proceeds from (repayments) issuance of short-term debt	'		0		-300
Net proceeds from issuances of long-term debt	'		'		'
Proceeds from share-based compensation plans	14		34		133
Advances from (to) affiliates	621		206		-28
Capital contribution from subsidiary	'		'		0
Net proceeds from (payments to) affiliated notional cash pooling programs	185		0		0
Dividends to parent company	'		0		0
Other	'		'		'
Net cash flows from (used for) financing activities	-939		-575		-654
Effect of foreign currency rate changes on cash and cash equivalents	'		'		0
Net increase (decrease) in cash	-103		-3		-202
Cash – beginning of year	103		106		308
Cash – end of year	0		103		106
ACE limited (Parent Gurantor) | Scenario, Previously Reported	'		'		'
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]	'		'		'
Net cash flows from operating activities	'		781		762
Purchases of fixed maturities available for sale	'		'		0
Purchases of fixed maturities held to maturity	'		'		0
Purchases of equity securities	'		'		0
Sales of fixed maturities available for sale	'		'		9
Sales of equity securities	'		'		0
Maturities and redemptions of fixed maturities available for sale	'		'		0
Maturities and redemptions of fixed maturities held to maturity	'		'		0
Net derivative instruments settlements	'		-1		-3
Advances from (to) affiliates	'		-2		41
Acquisition of subsidiaries (net of cash acquired)	'		'		0
Capital contribution to subsidiary	'		'		-385
Other	'		'		0
Net cash flows used for investing activities	'		-3		-338
Dividends paid on Common Shares	'		-815		459
Common Shares repurchased	'		'		0
Net proceeds from (repayments) issuance of short-term debt	'		'		-300
Proceeds from share-based compensation plans	'		34		133
Advances from (to) affiliates	'		'		0
Capital contribution from subsidiary	'		'		0
Dividends to parent company	'		'		0
Net cash flows from (used for) financing activities	'		-781		-626
Effect of foreign currency rate changes on cash and cash equivalents	'		0		0
Net increase (decrease) in cash	'		-3		-202
Cash – beginning of year	'		106		308
Cash – end of year	'		103		106
ACE INA Holdings Inc. (Subsidiary Issuer)	'		'		'
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]	'		'		'
Net cash flows from operating activities	-107		296		1,221
Purchases of fixed maturities available for sale	'		'		0
Purchases of fixed maturities held to maturity	'		'		0
Purchases of equity securities	'		'		0
Sales of fixed maturities available for sale	'		'		0
Sales of equity securities	'		'		0
Maturities and redemptions of fixed maturities available for sale	'		'		0
Maturities and redemptions of fixed maturities held to maturity	'		'		0
Net change in short-term investments	-4		-4		0
Net derivative instruments settlements	-1		'		0
Acquisition of subsidiaries (net of cash acquired)	'		'		76
Capital contribution to subsidiary	-1,097		-352		581
Other	-4		-33		-19
Net cash flows used for investing activities	-1,098		-389		-676
Dividends paid on Common Shares	'		'		0
Common Shares repurchased	'		'		0
Net proceeds from (repayments) issuance of short-term debt	'		0		0
Net proceeds from issuances of long-term debt	947		'		'
Proceeds from share-based compensation plans	'		0		0
Advances from (to) affiliates	621		-201		-721
Capital contribution from subsidiary	'		90		0
Net proceeds from (payments to) affiliated notional cash pooling programs	349		201		148
Dividends to parent company	0		0		0
Other	'		'		'
Net cash flows from (used for) financing activities	1,219		90		-573
Effect of foreign currency rate changes on cash and cash equivalents	'		'		0
Net increase (decrease) in cash	14		-3		-28
Cash – beginning of year	2		5		33
Cash – end of year	16		2		5
ACE INA Holdings Inc. (Subsidiary Issuer) | Scenario, Previously Reported	'		'		'
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]	'		'		'
Net cash flows from operating activities	'		1,744		1,053
Purchases of fixed maturities available for sale	'		-11,843		-12,203
Purchases of fixed maturities held to maturity	'		-384		-338
Purchases of equity securities	'		-70		-157
Sales of fixed maturities available for sale	'		7,347		9,718
Sales of equity securities	'		59		354
Maturities and redemptions of fixed maturities available for sale	'		2,759		1,784
Maturities and redemptions of fixed maturities held to maturity	'		1,045		933
Net derivative instruments settlements	'		-6		-24
Advances from (to) affiliates	'		'		0
Acquisition of subsidiaries (net of cash acquired)	'		111		-569
Capital contribution to subsidiary	'		'		0
Other	'		-395		420
Net cash flows used for investing activities	'		-1,599		-922
Dividends paid on Common Shares	'		'		0
Common Shares repurchased	'		'		0
Net proceeds from (repayments) issuance of short-term debt	'		1		-150
Proceeds from share-based compensation plans	'		13		3
Advances from (to) affiliates	'		-105		-149
Capital contribution from subsidiary	'		90		0
Dividends to parent company	'		0		0
Net cash flows from (used for) financing activities	'		-1		-296
Effect of foreign currency rate changes on cash and cash equivalents	'		-11		-26
Net increase (decrease) in cash	'		133		-191
Cash – beginning of year	'		382		573
Cash – end of year	'		515		382
Other ACE Limited Subsidiaries and Eliminations	'		'		'
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]	'		'		'
Net cash flows from operating activities	3,984	[3]	3,876	[3]	3,455
Purchases of fixed maturities available for sale	-21,504	[3]	-24,076	[3]	-24,601
Purchases of fixed maturities held to maturity	-447	[3]	-388	[3]	-340
Purchases of equity securities	-264	[3]	-135	[3]	-309
Sales of fixed maturities available for sale	10,519	[3]	14,884	[3]	18,294
Sales of equity securities	142	[3]	119	[3]	376
Maturities and redemptions of fixed maturities available for sale	6,941	[3]	5,523	[3]	3,720
Maturities and redemptions of fixed maturities held to maturity	1,488	[3]	1,451	[3]	1,279
Net change in short-term investments	-521	[3]	121	[3]	-309
Net derivative instruments settlements	-470	[3]	-280	[3]	-64
Acquisition of subsidiaries (net of cash acquired)	-977	[3]	-98	[3]	530
Capital contribution to subsidiary	'	[3]	-90	[3]	0
Other	-389	[3]	-522	[3]	-463
Net cash flows used for investing activities	-4,440	[3]	-3,491	[3]	-2,947
Dividends paid on Common Shares	'	[3]	'	[4]	0
Common Shares repurchased	-287	[3]	-11	[4]	-195
Net proceeds from (repayments) issuance of short-term debt	'		150		250
Net proceeds from issuances of long-term debt	'	[3]	'		'
Proceeds from share-based compensation plans	121	[3]	92		6
Advances from (to) affiliates	'	[3]	-5	[4]	749
Capital contribution from subsidiary	1,230	[3]	352		966
Net proceeds from (payments to) affiliated notional cash pooling programs	'	[3]	'	[4]	0
Dividends to parent company	-825	[4]	-750	[4]	-2,037
Other	113	[3]	'		'
Net cash flows from (used for) financing activities	352	[3]	-172		-261
Effect of foreign currency rate changes on cash and cash equivalents	-7	[3]	-5	[4]	-27
Net increase (decrease) in cash	-111	[3]	208	[4]	220
Cash – beginning of year	859	[3],[4]	651	[4]	431
Cash – end of year	748	[3]	859	[3],[4]	651	[4]
Other ACE Limited Subsidiaries and Eliminations | Scenario, Previously Reported	'		'		'
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]	'		'		'
Net cash flows from operating activities	'		1,920	[4]	2,395
Purchases of fixed maturities available for sale	'		-12,001	[4]	-12,375
Purchases of fixed maturities held to maturity	'		-4	[4]	-2
Purchases of equity securities	'		-65	[4]	-152
Sales of fixed maturities available for sale	'		7,422	[4]	8,244
Sales of equity securities	'		60	[4]	22
Maturities and redemptions of fixed maturities available for sale	'		2,764	[4]	1,936
Maturities and redemptions of fixed maturities held to maturity	'		406	[4]	346
Net derivative instruments settlements	'		-274	[4]	-40
Advances from (to) affiliates	'		'		0
Acquisition of subsidiaries (net of cash acquired)	'		-13		-37
Capital contribution to subsidiary	'		-90	[4]	0
Other	'		-160	[4]	62
Net cash flows used for investing activities	'		-1,929	[4]	-2,120
Dividends paid on Common Shares	'		'	[4]	0
Common Shares repurchased	'		-11	[4]	195
Net proceeds from (repayments) issuance of short-term debt	'		149		400
Proceeds from share-based compensation plans	'		79		3
Advances from (to) affiliates	'		107	[4]	108
Capital contribution from subsidiary	'		0		385
Dividends to parent company	'		-450	[4]	-740
Net cash flows from (used for) financing activities	'		-126	[4]	-39
Effect of foreign currency rate changes on cash and cash equivalents	'		6		-1
Net increase (decrease) in cash	'		-129	[4]	235
Cash – beginning of year	'		126		-109
Cash – end of year	'		-3	[4]	126
Consolidating Adjustments	'		'		'
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]	'		'		'
Net cash flows from operating activities	-825		-750		-2,037
Purchases of fixed maturities available for sale	-106		-115		323
Purchases of fixed maturities held to maturity	'		'		0
Purchases of equity securities	'		'		0
Sales of fixed maturities available for sale	-106		-115		-323
Sales of equity securities	'		'		0
Maturities and redemptions of fixed maturities available for sale	'		'		0
Maturities and redemptions of fixed maturities held to maturity	'		'		0
Net change in short-term investments	'		'		0
Net derivative instruments settlements	'		'		0
Acquisition of subsidiaries (net of cash acquired)	'		'		0
Capital contribution to subsidiary	1,230		442		-966
Other	'		'		0
Net cash flows used for investing activities	1,230		442		966
Dividends paid on Common Shares	'		'	[5]	0
Common Shares repurchased	'		'	[5]	0
Net proceeds from (repayments) issuance of short-term debt	'		'	[5]	0
Net proceeds from issuances of long-term debt	'		'		'
Proceeds from share-based compensation plans	'		0		0
Advances from (to) affiliates	'		'	[5]	0
Capital contribution from subsidiary	-1,230		-442		-966
Net proceeds from (payments to) affiliated notional cash pooling programs	-164		-201	[5]	-148
Dividends to parent company	825	[5]	750	[5]	2,037
Other	'		'		'
Net cash flows from (used for) financing activities	-241		107		923
Effect of foreign currency rate changes on cash and cash equivalents	'		'	[5]	0
Net increase (decrease) in cash	164		-201	[5]	-148
Cash – beginning of year	-349	[5]	-148	[5]	0
Cash – end of year	-185		-349	[5]	-148	[5]
Consolidating Adjustments | Scenario, Previously Reported	'		'		'
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]	'		'		'
Net cash flows from operating activities	'		-450		-740
Purchases of fixed maturities available for sale	'		'	[5]	0
Purchases of fixed maturities held to maturity	'		'	[5]	0
Purchases of equity securities	'		'	[5]	0
Sales of fixed maturities available for sale	'		'	[5]	0
Sales of equity securities	'		'	[5]	0
Maturities and redemptions of fixed maturities available for sale	'		'	[5]	0
Maturities and redemptions of fixed maturities held to maturity	'		'	[5]	0
Net derivative instruments settlements	'		'	[5]	0
Advances from (to) affiliates	'		2	[5]	-41
Acquisition of subsidiaries (net of cash acquired)	'		'	[5]	0
Capital contribution to subsidiary	'		90		385
Other	'		'	[5]	0
Net cash flows used for investing activities	'		92	[5]	344
Dividends paid on Common Shares	'		'	[5]	0
Common Shares repurchased	'		'	[5]	0
Net proceeds from (repayments) issuance of short-term debt	'		'	[5]	0
Proceeds from share-based compensation plans	'		0		0
Advances from (to) affiliates	'		-2	[5]	41
Capital contribution from subsidiary	'		-90		-385
Dividends to parent company	'		450	[5]	740
Net cash flows from (used for) financing activities	'		358	[5]	396
Effect of foreign currency rate changes on cash and cash equivalents	'		0		0
Net increase (decrease) in cash	'		'	[5]	0
Cash – beginning of year	'		0		0
Cash – end of year	'		'	[5]	$0
[1]	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[2]	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2010, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[3]	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2013 and December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[4]	Includes all other subsidiaries of ACE Limited and intercompany eliminations.
[5]	Includes ACE Limited parent company eliminations and certain consolidating adjustments.

Condensed_Unaudited_Quarterly_2

Condensed Unaudited Quarterly Financial Data (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 Information Disclosure [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	$4,363	$4,610	$4,067	$3,573	$3,848	$4,665	$3,783	$3,381	$16,613	$15,677	$15,387
Net investment income	557	522	534	531	567	533	537	544	2,144	2,181	2,242
Net realized gains (losses) including OTTI	154	40	104	206	272	-60	-394	260	504	78	-795
Total revenues	5,074	5,172	4,705	4,310	4,687	5,138	3,926	4,185	19,261	17,936	16,834
Losses and loss expenses	2,517	2,655	2,250	1,926	2,683	3,047	2,119	1,804	9,348	9,653	9,520
Policy benefits	136	138	110	131	142	130	102	147	515	521	401
Net income	$998	$916	$891	$953	$765	$640	$328	$973	$3,758	$2,706	$1,540
Basic earnings per share	$2.93	$2.68	$2.61	$2.80	$2.24	$1.88	$0.96	$2.87	$11.02	$7.96	$4.55
Diluted earnings per share	$2.90	$2.66	$2.59	$2.77	$2.22	$1.86	$0.96	$2.84	$10.92	$7.89	$4.52

Schedule_I_Details

Schedule I (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	$59,779
Fair Value	61,093
Amount at Which Shown in the Balance Sheet	60,928
Fixed maturities available for sale	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	48,406
Fair Value	49,254
Amount at Which Shown in the Balance Sheet	49,254
Fixed maturities available for sale | U.S. Treasury and agency	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	2,946
Fair Value	2,949
Amount at Which Shown in the Balance Sheet	2,949
Fixed maturities available for sale | Foreign	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	14,336
Fair Value	14,591
Amount at Which Shown in the Balance Sheet	14,591
Fixed maturities available for sale | Corporate securities	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	16,825
Fair Value	17,470
Amount at Which Shown in the Balance Sheet	17,470
Fixed maturities available for sale | Mortgage backed-securities	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	10,937
Fair Value	10,894
Amount at Which Shown in the Balance Sheet	10,894
Fixed maturities available for sale | States, municipalities, and political subdivisions	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	3,362
Fair Value	3,350
Amount at Which Shown in the Balance Sheet	3,350
Fixed maturities held to maturity	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	6,098
Fair Value	6,263
Amount at Which Shown in the Balance Sheet	6,098
Fixed maturities held to maturity | U.S. Treasury and agency	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	820
Fair Value	832
Amount at Which Shown in the Balance Sheet	820
Fixed maturities held to maturity | Foreign	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	864
Fair Value	897
Amount at Which Shown in the Balance Sheet	864
Fixed maturities held to maturity | Corporate securities	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	1,922
Fair Value	2,005
Amount at Which Shown in the Balance Sheet	1,922
Fixed maturities held to maturity | Mortgage backed-securities	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	1,341
Fair Value	1,379
Amount at Which Shown in the Balance Sheet	1,341
Fixed maturities held to maturity | States, municipalities, and political subdivisions	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	1,151
Fair Value	1,150
Amount at Which Shown in the Balance Sheet	1,151
Industrial, miscellaneous, and all others	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	841
Fair Value	837
Amount at Which Shown in the Balance Sheet	837
Short-term investments	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	1,763
Fair Value	1,763
Amount at Which Shown in the Balance Sheet	1,763
Other investments	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	2,671
Fair Value	2,976
Amount at Which Shown in the Balance Sheet	2,976
Short-term investments and Other investments, total	'
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]	'
Cost or Amortized Cost	4,434
Fair Value	4,739
Amount at Which Shown in the Balance Sheet	$4,739

Schedule_II_BALANCE_SHEETS_Par

Schedule II (BALANCE SHEETS - Parent Company Only) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2010
In Millions, unless otherwise specified
Assets	'	'	'		'
Investments in subsidiaries and affiliates on equity basis	'	'	'		'
Short-term investments	1,763	2,228	'		'
Other investments	2,976	2,716	'		'
Cash	579	615	614	[1]	772
Due from subsidiaries and affiliates, net	'	'	'		'
Other assets	3,330	2,871	'		'
Total assets	94,510	92,545	'		'
Liabilities	'	'	'		'
Accounts payable, accrued expenses, and other liabilities	4,810	5,397	'		'
Bank Overdrafts	'	0	'		'
Short-term debt	1,901	1,401	'		'
Total liabilities	65,685	65,014	'		'
Stockholders' Equity Attributable to Parent [Abstract]	'	'	'		'
Common Shares	8,899	9,591	'		'
Common Shares in treasury	-255	-159	'		'
Additional paid-in capital	5,238	5,179	'		'
Retained earnings	13,791	10,033	'		'
Accumulated other comprehensive income	1,152	2,887	'		'
Total liabilities and shareholders’ equity	94,510	92,545	'		'
Parent Company Only	'	'	'		'
Assets	'	'	'		'
Investments in subsidiaries and affiliates on equity basis	28,351	27,251	'		'
Short-term investments	2	1	'		'
Other investments	30	30	'		'
Total investments	28,383	27,282	'		'
Cash	0	103	106		308
Due from subsidiaries and affiliates, net	844	204	'		'
Other assets	5	13	'		'
Total assets	29,232	27,602	'		'
Liabilities	'	'	'		'
Accounts payable, accrued expenses, and other liabilities	222	71	'		'
Bank Overdrafts	185	'	'		'
Short-term debt	'	'	'		'
Total liabilities	407	71	'		'
Stockholders' Equity Attributable to Parent [Abstract]	'	'	'		'
Common Shares	8,899	9,591	'		'
Common Shares in treasury	-255	-159	'		'
Additional paid-in capital	5,238	5,179	'		'
Retained earnings	13,791	10,033	'		'
Accumulated other comprehensive income	1,152	2,887	'		'
Total shareholders' equity	28,825	27,531	'		'
Total liabilities and shareholders’ equity	$29,232	$27,602	'		'
[1]	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

Schedule_II_Schedule_II_STATEM

Schedule II Schedule II (STATEMENTS OF OPERATIONS - Parent Company Only) (Details) (USD $)	3 Months Ended								12 Months Ended
	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
Condensed Financial Statements, Captions [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Equity in net income of subsidiaries and affiliates	'	'	'	'	'	'	'	'	$119,000,000	$80,000,000	$32,000,000
Net realized gains (losses)	154,000,000	40,000,000	104,000,000	206,000,000	272,000,000	-60,000,000	-394,000,000	260,000,000	504,000,000	78,000,000	-795,000,000
Total revenues	5,074,000,000	5,172,000,000	4,705,000,000	4,310,000,000	4,687,000,000	5,138,000,000	3,926,000,000	4,185,000,000	19,261,000,000	17,936,000,000	16,834,000,000
Administrative and other (income) expense	'	'	'	'	'	'	'	'	-2,211,000,000	-2,096,000,000	-2,068,000,000
Income tax expense (benefit)	'	'	'	'	'	'	'	'	480,000,000	270,000,000	502,000,000
Total expenses	'	'	'	'	'	'	'	'	-15,023,000,000	-14,960,000,000	-14,792,000,000
Net income	998,000,000	916,000,000	891,000,000	953,000,000	765,000,000	640,000,000	328,000,000	973,000,000	3,758,000,000	2,706,000,000	1,540,000,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	'	'	'	'	'	'	'	'	2,023,000,000	3,682,000,000	1,857,000,000
Parent Company Only	'	'	'	'	'	'	'	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Investment income, including intercompany interest income	'	'	'	'	'	'	'	'	34,000,000	34,000,000	39,000,000
Equity in net income of subsidiaries and affiliates	'	'	'	'	'	'	'	'	3,580,000,000	2,590,000,000	1,459,000,000
Net realized gains (losses)	'	'	'	'	'	'	'	'	0	17,000,000	-4,000,000
Total revenues	'	'	'	'	'	'	'	'	3,614,000,000	2,641,000,000	1,494,000,000
Administrative and other (income) expense	'	'	'	'	'	'	'	'	-161,000,000	-75,000,000	-56,000,000
Income tax expense (benefit)	'	'	'	'	'	'	'	'	17,000,000	10,000,000	10,000,000
Total expenses	'	'	'	'	'	'	'	'	-144,000,000	-65,000,000	-46,000,000
Net income	'	'	'	'	'	'	'	'	3,758,000,000	2,706,000,000	1,540,000,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	'	'	'	'	'	'	'	'	$2,023,000,000	$3,682,000,000	$1,857,000,000

Schedule_II_STATEMENTS_OF_CASH

Schedule II (STATEMENTS OF CASH FLOWS - Parent Company Only) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]	'	'		'
Net cash flows from operating activities	$4,022	$3,995		$3,470
Purchases of fixed maturities available for sale	-21,340	-23,572		-23,523
Sales of fixed maturities available for sale	10,355	14,321		17,176
Net change in short-term investments	524	117		-300
Net derivative instruments settlements	-471	-281		-67
Other	393	555		482
Net cash flows used for investing activities	-4,442	-3,439		-3,036
Dividends paid on Common Shares	-517	-815		-459
Advances (to) from affiliates	'	-206		28
Net proceeds from (payments to) affiliated notional cash pooling programs	'	'		0
Proceeds from share-based compensation plans	135	126		139
Net cash flows from (used for) financing activities	391	-550		-565
Net increase (decrease) in cash	-36	1		-158
Cash – beginning of year	615	614	[1]	772
Cash – end of year	579	615		614	[1]
Parent Company Only	'	'		'
Condensed Financial Statements, Captions [Line Items]	'	'		'
Net cash flows from operating activities	970	573		831
Net change in short-term investments	-1	0		9
Net derivative instruments settlements	0	-1		-3
Capital contributions to subsidiaries	-133	0		-385
Net cash flows used for investing activities	-134	-1		-379
Dividends paid on Common Shares	-517	-815		-459
Net proceeds from issuance (repayment) of short-term debt	0	0		-300
Advances (to) from affiliates	621	'		'
Net proceeds from (payments to) affiliated notional cash pooling programs	185	0		0
Proceeds from share-based compensation plans	14	34		133
Net cash flows from (used for) financing activities	-939	-575		-654
Net increase (decrease) in cash	-103	-3		-202
Cash – beginning of year	103	106		308
Cash – end of year	$0	$103		$106
[1]	ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

Schedule_IV_SUPPLEMENTAL_INFOR

Schedule IV (SUPPLEMENTAL INFORMATION CONCERNING REINSURANCE) (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
Supplemental Schedule of Reinsurance Premiums for Insurance Companies [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Direct Amount	'	'	'	'	'	'	'	'	$18,856	$17,802	$17,534
Ceded To Other Companies	'	'	'	'	'	'	'	'	5,722	5,427	5,496
Assumed From Other Companies	'	'	'	'	'	'	'	'	3,479	3,302	3,349
Net Amount	$4,363	$4,610	$4,067	$3,573	$3,848	$4,665	$3,783	$3,381	$16,613	$15,677	$15,387
Percentage of Amount Assumed to Net	'	'	'	'	'	'	'	'	21.00%	21.00%	22.00%

Schedule_VI_SUPPLEMENTARY_INFO

Schedule VI (SUPPLEMENTARY INFORMATION CONCERNING PROPERTY AND CASUALTY OPERATIONS) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]	'	'	'
Deferred Policy Acquisition Costs	$1,865	$1,757	$1,512
Net Reserves for Unpaid Losses	26,831	26,547	25,875
Unearned Premiums	7,539	6,864	6,334
Net Premiums Earned	15,708	14,764	14,523
Net Investment Income	1,977	2,018	2,107
Net Losses and Loss Expenses Incurred Related to Current Year	9,878	10,132	10,076
Net Losses and Loss Expenses Incurred Related to Prior Year	-530	-479	-556
Amortization of Deferred Policy Acquisition Costs	2,447	2,254	2,291
Net Paid Losses and Loss Expenses	8,977	9,219	8,866
Net Premiums Written	$16,069	$15,107	$14,455