Chubb Limited (CB) 10-Q 29 Apr 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 15, 2015
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	ACE
Entity Registrant Name	ACE Ltd
Entity Central Index Key	896159
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		326,592,412

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Investments [Abstract]
Fixed maturities available for sale, at fair value (amortized cost - $48,384 and $47,826) (includes hybrid financial instruments of $284 and $274)	$50,410		$49,395
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	6,982		7,331
Equity securities, at fair value (cost – $447 and $440)	536		510
Short-term investments, at fair value and amortized cost	2,536		2,322
Other investments (cost – $3,096 and $2,999)	3,430		3,346
Total investments	63,894		62,904
Cash	948	[1],[2]	655	[1],[3]
Securities lending collateral	1,033		1,330
Accrued investment income	530		552
Insurance and reinsurance balances receivable	5,026		5,426
Reinsurance recoverable on losses and loss expenses	11,588		11,992
Reinsurance recoverable on policy benefits	215		217
Deferred policy acquisition costs	2,683		2,601
Value of business acquired	440		466
Goodwill and other intangible assets	5,516		5,724
Prepaid reinsurance premiums	1,981		2,026
Deferred tax assets	224		295
Investments in partially-owned insurance companies	590		504
Other assets	3,730		3,556
Total assets	98,398		98,248
Liabilities
Unpaid losses and loss expenses	37,326		38,315
Unearned premiums	8,182		8,222
Future policy benefits	4,744		4,754
Insurance and reinsurance balances payable	4,198		4,095
Securities lending payable	1,034		1,331
Accounts payable, accrued expenses, and other liabilities	6,194		5,726
Short-term debt	2,552		2,552
Long-term debt	4,157		3,357
Trust preferred securities	309		309
Total liabilities	68,696		68,661
Commitments and contingencies
Shareholders’ equity
Common Shares (CHF 24.15 and CHF 24.77 par value; 342,832,412 shares issued; 327,084,762 and 328,659,686 shares outstanding)	7,833		8,055
Common Shares in treasury (15,747,650 and 14,172,726 shares)	-1,645		-1,448
Additional paid-in capital	5,037		5,145
Retained earnings	17,325		16,644
Accumulated other comprehensive income (AOCI)	1,152		1,191
Total shareholders’ equity	29,702		29,587
Total liabilities and shareholders’ equity	$98,398		$98,248
[1]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015 and December 31, 2014, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[2]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[3]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2014, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical)	Mar. 31, 2015	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2014
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	$48,384		$47,826
Fixed maturities available for sale, hybrid financial instruments	284		274
Fixed maturities held to maturity, at amortized cost	7,307		7,589
Equity securities, at cost	447		440
Other investments, cost	$3,096		$2,999
Common Shares, par value		24.15		24.77
Common Shares, shares issued	342,832,412	342,832,412	342,832,412	342,832,412
Common Shares, shares outstanding	327,084,762	327,084,762	328,659,686	328,659,686
Common Shares in treasury, shares	15,747,650	15,747,650	14,172,726	14,172,726

Consolidated_Statements_Of_Ope

Consolidated Statements Of Operations and Comprehensive Income (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues
Net premiums written	$4,076	$4,185
Increase in unearned premiums	-149	-215
Net premiums earned	3,927	3,970
Net investment income	551	553
Net realized gains (losses):
Other-than-temporary impairment (OTTI) losses gross	-13	-12
Portion of OTTI losses recognized in other comprehensive income (OCI)	0	1
Net OTTI losses recognized in income	-13	-11
Net realized gains (losses) excluding OTTI losses	-76	-93
Total net realized gains (losses) (includes $(3) and $6 reclassified from AOCI)	-89	-104
Total revenues	4,389	4,419
Expenses
Losses and loss expenses	2,122	2,161
Policy benefits	142	114
Policy acquisition costs	707	728
Administrative expenses	554	535
Interest expense	68	71
Other (income) expense	-5	-17
Total expenses	3,588	3,592
Income before income tax	801	827
Income tax expense (benefit) (includes $4 and $(3) on reclassified unrealized gains and losses)	120	93
Net income	681	734
Other comprehensive income (loss)
Unrealized appreciation	441	519
Reclassification adjustment for net realized (gains) losses included in net income	3	-6
Unrealized appreciation (Depreciation) after reclassification adjustment	444	513
Change in:
Cumulative translation adjustment	-421	-33
Pension liability	13	-8
Other comprehensive income, before income tax	36	472
Income tax expense related to OCI items	-75	-98
Other comprehensive income (loss)	-39	374
Comprehensive income	642	1,108
Earnings per share
Basic earnings per share	$2.08	$2.16
Diluted earnings per share	$2.05	$2.14
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Net realized gains (losses):
Total net realized gains (losses) (includes $(3) and $6 reclassified from AOCI)	-3	6
Expenses
Income tax expense (benefit) (includes $4 and $(3) on reclassified unrealized gains and losses)	$4	($3)

Consolidated_Statements_Of_Ope1

Consolidated Statements Of Operations and Comprehensive Income Consolidated Statements of Operations and Comprehensive Income (Parenthetical) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income tax expense (benefit)	$120	$93
Net realized gains (losses)	-89	-104
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Income tax expense (benefit)	4	-3
Net realized gains (losses)	($3)	$6

Consolidated_Statements_Of_Sha

Consolidated Statements Of Shareholders' Equity (USD $)	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Net Unrealized Investment Gain (Loss) [Member]	Accumulated Translation Adjustment [Member]	Accumulated Defined Benefit Plans Adjustment [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
In Millions
Balance - beginning of period at Dec. 31, 2013		$8,899	($255)	$5,238	$13,791	$1,174	$63	($85)
Dividends declared on Common Shares – par value reduction		-175
Net shares redeemed under employee share-based compensation plans			144	-154
Common Shares repurchased			-332
Exercise of stock options				-18
Share-based compensation expense and other				52
Funding of dividends declared to Retained earnings				-81
Net income	734				734
Funding of dividends declared from Additional paid-in capital					81
Dividends declared on Common Shares					-81
Change in period, before reclassification from AOCI, net of income tax expense of $(87) and $(90)						429
Amounts reclassified from AOCI, net of income tax benefit (expense) of $4 and $(3)						-9
Change in period, net of income tax expense of $(83) and $(93)						420
Change in period, net of income tax benefit (expense) of $11 and $(8)							-41
Change in period, net of income tax benefit (expense) of $(3) and $3								-5
Balance - end of period at Mar. 31, 2014	29,369	8,724	-443	5,037	14,525	1,594	22	-90	1,526
Balance - beginning of period at Dec. 31, 2014	29,587	8,055	-1,448	5,145	16,644	1,851	-581	-79
Dividends declared on Common Shares – par value reduction		-222
Net shares redeemed under employee share-based compensation plans			143	-153
Common Shares repurchased			-340
Exercise of stock options				-18
Share-based compensation expense and other				63
Funding of dividends declared to Retained earnings				0
Net income	681				681
Funding of dividends declared from Additional paid-in capital					0
Dividends declared on Common Shares					0
Change in period, before reclassification from AOCI, net of income tax expense of $(87) and $(90)						354
Amounts reclassified from AOCI, net of income tax benefit (expense) of $4 and $(3)						7
Change in period, net of income tax expense of $(83) and $(93)						361
Change in period, net of income tax benefit (expense) of $11 and $(8)							-410
Change in period, net of income tax benefit (expense) of $(3) and $3								10
Balance - end of period at Mar. 31, 2015	$29,702	$7,833	($1,645)	$5,037	$17,325	$2,212	($991)	($69)	$1,152

Consolidated_Statements_Of_Sha1

Consolidated Statements Of Shareholders' Equity (Parenthetical) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Net unrealized appreciation on investments, Change in period, income tax (expense) benefit	($83)	($93)
Cumulative translation adjustment, Change in period, income tax(expense) benefit	11	-8
Pension liability adjustment, Change in period, income tax (expense) benefit	-3	3
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Tax	-87	-90
Income tax benefit (expense) from reclassification of unrealized gains	$4	($3)

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Cash flows from operating activities
Net income	$681		$734
Adjustments to reconcile net income to net cash flows from operating activities
Net realized (gains) losses	89		104
Amortization of premiums/discounts on fixed maturities	36		53
Deferred income taxes	7		0
Unpaid losses and loss expenses	-320		-598
Unearned premiums	212		270
Future policy benefits	48		56
Insurance and reinsurance balances payable	158		112
Accounts payable, accrued expenses, and other liabilities	-46		-64
Income taxes payable	20		15
Insurance and reinsurance balances receivable	240		264
Reinsurance recoverable on losses and loss expenses	185		478
Reinsurance recoverable on policy benefits	2		-2
Deferred policy acquisition costs	-128		-99
Prepaid reinsurance premiums	-32		-52
Other	-77		-21
Net cash flows from operating activities	1,075		1,250
Cash flows from investing activities
Purchases of fixed maturities available for sale	-4,305		-3,522
Purchases of to be announced mortgage-backed securities	-31		0
Purchases of fixed maturities held to maturity	-21		-30
Purchases of equity securities	-39		-37
Sales of fixed maturities available for sale	2,002		2,208
Sales of equity securities	28		27
Maturities and redemptions of fixed maturities available for sale	1,481		1,550
Maturities and redemptions of fixed maturities held to maturity	324		212
Net change in short-term investments	-255		-765
Net derivative instruments settlements	-51		-96
Other	-153		-50
Net cash flows used for investing activities	-1,020		-503
Cash flows from financing activities
Dividends paid on Common Shares	-214		-214
Common Shares repurchased	-347		-335
Policyholder contract deposits	101		51
Policyholder contract withdrawals	-40		-14
Proceeds from issuance of long-term debt	800		0
Proceeds from issuance of short-term debt	477		426
Repayment of short-term debt	-477		-426
Proceeds from share-based compensation plans, including windfall tax benefits	39		40
Other	-6		0
Net cash flows from (used for) financing activities	333		-472
Effect of foreign currency rate changes on cash and cash equivalents	-95		-7
Net increase in cash	293		268
Cash – beginning of period	655	[1],[2]	579	[3]
Cash – end of period	948	[1],[4]	847	[3]
Supplemental cash flow information
Taxes paid	96		60
Interest paid	$48		$51
[1]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015 and December 31, 2014, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[2]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2014, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[3]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2014 and December 31, 2013, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[4]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

General

General	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	General
	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 10 for additional information.
	The interim unaudited 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, including internal reinsurance transactions, have been eliminated.
	The results of operations and cash flows for any interim period are not necessarily indicative of the results for the full year. These consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in our 2014 Form 10-K.
	b) Accounting guidance not yet adopted
	Presentation of Debt Issuance Costs
	In April 2015, the Financial Accounting Standards Board issued new guidance related to the accounting for debt issuance costs.  The new guidance requires presentation of debt issuance costs in the balance sheet as a deduction from the carrying amount of the related debt liability instead of a deferred charge.  The new guidance requires retrospective adoption and is effective for interim and annual reporting periods beginning after December 15, 2015, with early adoption permitted. The adoption of this guidance will not have any effect on our results of operations and financial condition.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Acquisitions	Acquisitions
	Large Corporate Account P&C Insurance Business of Itaú Seguros, S.A. (Itaú Seguros)
	On October 31, 2014, we expanded our presence in Brazil with the acquisition of the large corporate account property and casualty (P&C) insurance business of Itaú Seguros, Brazil's leading carrier for that business, for $610 million in cash, subject to a working capital adjustment under the purchase agreement expected to be finalized in the second quarter of 2015. This acquisition generated $449 million of goodwill, attributable to expected growth and profitability, none of which is currently deductible for income tax purposes, and other intangible assets of $60 million, primarily related to renewal rights, based on ACE’s preliminary purchase price allocation. Goodwill may become deductible for income tax purposes under Brazilian tax law if this acquired entity is merged with certain ACE legal entities.
	The Siam Commercial Samaggi Insurance PCL (Samaggi)
	We and our local partner acquired 60.86 percent of Samaggi, a general insurance company in Thailand, from Siam Commercial Bank on April 28, 2014, and subsequently acquired an additional 32.17 percent ownership, through a mandatory tender offer, which expired on June 17, 2014. The purchase price for 93.03 percent of the company was $176 million in cash. This acquisition expands our presence in Thailand and Southeast Asia.
	The acquisition generated $46 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 $80 million based on ACE’s preliminary purchase price allocation.  The other intangible assets primarily relate to a bancassurance agreement.
	Goodwill and other intangible assets arising from the acquisitions described above are included in our Insurance – Overseas General segment. The consolidated financial statements include results of acquired businesses from the acquisition dates.
	Fireman's Fund Insurance Company High Net Worth Personal Lines Insurance Business in the U.S. (Fireman's Fund)
	On April 1, 2015, we acquired the Fireman's Fund Insurance Company high net worth personal lines insurance business in the U.S., which included the renewal rights for new and existing business and reinsurance of all existing reserves, from Allianz of America, Inc. for $365 million in cash. The acquisition expands our position as one of the largest high net worth personal lines insurers in the U.S. The Fireman’s Fund business is being integrated into our existing high net worth personal lines business, ACE Private Risk Services, which offers a broad range of coverage including homeowners, automobile, umbrella and excess liability, collectibles and yachts.

Investments

Investments	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Investments	Investments
	a) Fixed maturities
	31-Mar-15	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	$	2,793		$	98		$	(2	)	$	2,889		$	—
	Foreign	14,262			761			(76		)	14,947			—
	Corporate securities	17,259			834			(94		)	17,999			(6		)
	Mortgage-backed securities	10,459			362			(13		)	10,808			(1		)
	States, municipalities, and political subdivisions	3,611			160			(4		)	3,767			—
		$	48,384		$	2,215		$	(189	)	$	50,410		$	(7	)
	Held to maturity
	U.S. Treasury and agency	$	756		$	24		$	—		$	780		$	—
	Foreign	816			57			—			873			—
	Corporate securities	2,249			122			—			2,371			—
	Mortgage-backed securities	1,907			77			(1		)	1,983			—
	States, municipalities, and political subdivisions	1,254			47			(1		)	1,300			—
		$	6,982		$	327		$	(2	)	$	7,307		$	—
	31-Dec-14	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	$	2,741		$	87		$	(8	)	$	2,820		$	—
	Foreign	14,703			629			(90		)	15,242			—
	Corporate securities	16,897			704			(170		)	17,431			(7		)
	Mortgage-backed securities	10,011			304			(29		)	10,286			(1		)
	States, municipalities, and political subdivisions	3,474			147			(5		)	3,616			—
		$	47,826		$	1,871		$	(302	)	$	49,395		$	(8	)
	Held to maturity
	U.S. Treasury and agency	$	832		$	20		$	(2	)	$	850		$	—
	Foreign	916			47			—			963			—
	Corporate securities	2,323			102			(2		)	2,423			—
	Mortgage-backed securities	1,983			57			(1		)	2,039			—
	States, municipalities, and political subdivisions	1,277			40			(3		)	1,314			—
		$	7,331		$	266		$	(8	)	$	7,589		$	—
	As discussed in Note 3 d), if a credit loss is incurred 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 both the three months ended March 31, 2015 and 2014, $4 million of net unrealized appreciation related to such securities is included in OCI. At March 31, 2015 and December 31, 2014, AOCI included cumulative net unrealized depreciation of $2 million and $3 million, respectively, related to securities remaining in the investment portfolio 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 7 a) (iv)) and are included in the category, “Mortgage-backed securities”. Approximately 82 percent and 83 percent of the total mortgage-backed securities at March 31, 2015 and December 31, 2014, 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-Mar						31-Dec
					2015						2014
	(in millions of U.S. dollars)	Amortized Cost			Fair Value			Amortized Cost			Fair Value
	Available for sale
	Due in 1 year or less	$	2,021		$	2,042		$	2,187		$	2,206
	Due after 1 year through 5 years	16,209			16,735			15,444			15,857
	Due after 5 years through 10 years	15,047			15,649			15,663			16,089
	Due after 10 years	4,648			5,176			4,521			4,957
		37,925			39,602			37,815			39,109
	Mortgage-backed securities	10,459			10,808			10,011			10,286
		$	48,384		$	50,410		$	47,826		$	49,395
	Held to maturity
	Due in 1 year or less	$	318		$	321		$	353		$	355
	Due after 1 year through 5 years	2,594			2,706			2,603			2,693
	Due after 5 years through 10 years	1,214			1,270			1,439			1,489
	Due after 10 years	949			1,027			953			1,013
		5,075			5,324			5,348			5,550
	Mortgage-backed securities	1,907			1,983			1,983			2,039
		$	6,982		$	7,307		$	7,331		$	7,589
	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-Mar			31-Dec
	(in millions of U.S. dollars)	2015			2014
	Cost	$	447		$	440
	Gross unrealized appreciation	99			83
Gross unrealized depreciation	(10		)	(13		)
Fair value	$	536		$	510
c) Investments in partially-owned insurance companies
On March 27, 2015 and April 14, 2015, we paid approximately $70 million and $20 million, respectively, to acquire 11.3 percent of the common equity of ABR Reinsurance Capital Holdings Ltd. and warrants to acquire 0.5 percent of additional equity.  ABR Reinsurance Capital Holdings Ltd., is the parent company of ABR Reinsurance Ltd. (ABR Re), an innovative, independent reinsurance company. Through long-term arrangements, ACE will be the sole source of reinsurance risks ceded to ABR Re, and BlackRock, Inc. will be ABR Re’s exclusive investment management service provider. As an investor, ACE is expected to benefit from underwriting profit generated by ABR Re’s reinsuring a wide range of ACE’s primary insurance business and the income and capital appreciation BlackRock, Inc. seeks to deliver through its investment management services. Our minority ownership interest will be accounted for under the equity method of accounting.
d) 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 incurred, 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. For mutual funds included in equity securities in our consolidated balance sheet, we employ analysis similar to fixed maturities, when applicable.
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.
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 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.
For both the three months ended March 31, 2015 and 2014, credit losses recognized in Net income for corporate securities were $4 million.
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.
For the three months ended March 31, 2015 and 2014, there were no credit losses recognized in Net income for mortgage-backed securities.
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”:
	Three Months Ended
	31-Mar
(in millions of U.S. dollars)	2015			2014
Fixed maturities:
OTTI on fixed maturities, gross	$	(13	)	$	(6	)
OTTI on fixed maturities recognized in OCI (pre-tax)	—			1
OTTI on fixed maturities, net	(13		)	(5		)
Gross realized gains excluding OTTI	44			36
Gross realized losses excluding OTTI	(35		)	(20		)
Total fixed maturities	(4		)	11
Equity securities:
OTTI on equity securities	—			(6		)
Gross realized gains excluding OTTI	3			2
Gross realized losses excluding OTTI	(2		)	(1		)
Total equity securities	1			(5		)
OTTI on other investments	—			—
Foreign exchange losses	(31		)	(9		)
Investment and embedded derivative instruments	1			(25		)
Fair value adjustments on insurance derivative	(45		)	(48		)
S&P put options and futures	(12		)	(19		)
Other derivative instruments	—			(2		)
Other	1			(7		)
Net realized gains (losses)	$	(89	)	$	(104	)
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:
	Three Months Ended
	31-Mar
(in millions of U.S. dollars)	2015			2014
Balance of credit losses related to securities still held – beginning of period	$	28		$	37
Additions where no OTTI was previously recorded	3			2
Additions where an OTTI was previously recorded	1			2
Reductions for securities sold during the period	(10		)	(6		)
Balance of credit losses related to securities still held – end of period	$	22		$	35
e) Gross unrealized loss
At March 31, 2015, there were 3,313 fixed maturities out of a total of 33,429 fixed maturities in an unrealized loss position. The largest single unrealized loss in the fixed maturities was $3 million. There were 78 equity securities out of a total of 306 equity securities in an unrealized loss position. The largest single unrealized loss in the equity securities was $1 million. Fixed maturities in an unrealized loss position at March 31, 2015, 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.
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-Mar-15	Fair Value			Gross			Fair Value			Gross			Fair Value			Gross
				Unrealized						Unrealized						Unrealized
(in millions of U.S. dollars)				Loss						Loss						Loss
U.S. Treasury and agency	$	443		$	(1	)	$	141		$	(1	)	$	584		$	(2	)
Foreign	1,747			(64		)	317			(12		)	2,064			(76		)
Corporate securities	2,140			(79		)	500			(15		)	2,640			(94		)
Mortgage-backed securities	1,301			(6		)	560			(8		)	1,861			(14		)
States, municipalities, and political subdivisions	462			(3		)	89			(2		)	551			(5		)
Total fixed maturities	6,093			(153		)	1,607			(38		)	7,700			(191		)
Equity securities	68			(10		)	—			—			68			(10		)
Other investments	92			(6		)	—			—			92			(6		)
Total	$	6,253		$	(169	)	$	1,607		$	(38	)	$	7,860		$	(207	)
	0 – 12 Months						Over 12 Months						Total
31-Dec-14	Fair Value			Gross			Fair Value			Gross			Fair Value			Gross
				Unrealized						Unrealized						Unrealized
(in millions of U.S. dollars)				Loss						Loss						Loss
U.S. Treasury and agency	$	350		$	(1	)	$	666		$	(9	)	$	1,016		$	(10	)
Foreign	2,262			(75		)	375			(15		)	2,637			(90		)
Corporate securities	4,684			(150		)	738			(22		)	5,422			(172		)
Mortgage-backed securities	704			(2		)	1,663			(28		)	2,367			(30		)
States, municipalities, and political subdivisions	458			(3		)	490			(5		)	948			(8		)
Total fixed maturities	8,458			(231		)	3,932			(79		)	12,390			(310		)
Equity securities	101			(13		)	—			—			101			(13		)
Total	$	8,559		$	(244	)	$	3,932		$	(79	)	$	12,491		$	(323	)
f) 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, which represent ACE's agreement to sell securities and repurchase them at a future date for a predetermined price. 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 March 31, 2015 and December 31, 2014, are investments, primarily fixed maturities, totaling $16.5 billion and $16.3 billion, respectively, and cash of $102 million and $117 million, respectively.
The following table presents the components of restricted assets:
	31-Mar			31-Dec
(in millions of U.S. dollars)	2015			2014
Trust funds	$	11,132		$	10,838
Deposits with non-U.S. regulatory authorities	2,296			2,305
Assets pledged under repurchase agreements	1,459			1,431
Deposits with U.S. regulatory authorities	1,336			1,345
Other pledged assets	446			457
	$	16,669		$	16,376
g) Transfers of securities
During April 2015, we transferred securities, considered essential holdings in a diversified portfolio, with a total fair value of approximately $1.8 billion from Fixed maturities available for sale to Fixed maturities held to maturity. These securities, which we have the intent and ability to hold to maturity, will be transferred given the growth in ACE’s investment portfolio over the last several years, as well as continued efforts to manage the diversification of our global portfolio. The net unrealized appreciation at the date of the transfer will be reported in the carrying value of the transferred investments and will be amortized through OCI over the remaining life of the securities using the effective interest method in a manner consistent with the amortization of any premium or discount. This transfer represents a non-cash transaction and will not impact the Consolidated Statements of Cash Flows.

Fair_value_measurements

Fair value measurements	3 Months Ended
	Mar. 31, 2015
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 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 single broker quote (typically from 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, an increase in 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. Other derivative instruments based on unobservable inputs are classified 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 within Level 1 in the valuation hierarchy on the same basis as other equity securities traded in active markets. 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 factors, including interest rates, equity markets, credit risk, current account value, market volatility, expected annuitization rates, and other 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.
	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.
	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.
	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 regularly re-evaluated by management and enhanced, as appropriate, based upon additional experience obtained related to policyholder behavior and availability of updated information such as market conditions, market participant assumptions, and demographics of in-force annuities. Because of the significant use of unobservable inputs including policyholder behavior, GLB reinsurance is classified within Level 3. During the three months ended March 31, 2015, no material changes were made to actuarial or behavioral assumptions. We made minor technical refinements to the model with an unfavorable net income impact of approximately $400 thousand and $3 million for the three months ended March 31, 2015 and 2014, respectively. For detailed information on our lapse and annuitization rate assumptions, refer to Note 4 to the Consolidated Financial Statements of our 2014 Form 10-K.
	Financial instruments measured at fair value on a recurring basis, by valuation hierarchy
	31-Mar-15	Level 1				Level 2				Level 3				Total
	(in millions of U.S. dollars)
	Assets:
	Fixed maturities available for sale
	U.S. Treasury and agency	$	1,747			$	1,142			$	—			$	2,889
	Foreign	—				14,925				22				14,947
	Corporate securities	—				17,832				167				17,999
	Mortgage-backed securities	—				10,775				33				10,808
	States, municipalities, and political subdivisions	—				3,767				—				3,767
		1,747				48,441				222				50,410
	Equity securities	518				16				2				536
	Short-term investments	1,469				1,067				—				2,536
	Other investments	364				277				2,789				3,430
	Securities lending collateral	—				1,033				—				1,033
	Investment derivative instruments	21				—				—				21
	Other derivative instruments	—				1				—				1
	Separate account assets	1,488				86				—				1,574
	Total assets measured at fair value	$	5,607			$	50,921			$	3,013			$	59,541
	Liabilities:
	Investment derivative instruments	$	25			$	—			$	—			$	25
	Other derivative instruments	3				—				4				7
	GLB(1)	—				—				451				451
	Total liabilities measured at fair value	$	28			$	—			$	455			$	483
	(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 for additional information.
	December 31, 2014	Level 1				Level 2				Level 3				Total
	(in millions of U.S. dollars)
	Assets:
	Fixed maturities available for sale
	U.S. Treasury and agency	$	1,680			$	1,140			$	—			$	2,820
	Foreign	—				15,220				22				15,242
Corporate securities	—				17,244				187				17,431
Mortgage-backed securities	—				10,271				15				10,286
States, municipalities, and political subdivisions	—				3,616				—				3,616
	1,680				47,491				224				49,395
Equity securities	492				16				2				510
Short-term investments	1,183				1,139				—				2,322
Other investments	370				257				2,719				3,346
Securities lending collateral	—				1,330				—				1,330
Investment derivative instruments	18				—				—				18
Other derivative instruments	—				2				—				2
Separate account assets	1,400				90				—				1,490
Total assets measured at fair value	$	5,143			$	50,325			$	2,945			$	58,413
Liabilities:
Investment derivative instruments	$	36			$	—			$	—			$	36
Other derivative instruments	21				—				4				25
GLB(1)	—				—				406				406
Total liabilities measured at fair value	$	57			$	—			$	410			$	467
(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 for additional information.
There were no transfers between Level 1 and Level 2 for the three months ended March 31, 2015 and 2014.
Fair value of alternative investments
Included in Other investments in the fair value hierarchy are investment funds, limited partnerships, and partially-owned investment companies measured at fair value using NAV as a practical expedient. At March 31, 2015 and December 31, 2014, 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-Mar								31-Dec
	Expected						2015								2014
	Liquidation
(in millions of U.S. dollars)	Period of Underlying Assets		Fair				Maximum				Fair				Maximum
			Value				Future Funding				Value				Future Funding
							Commitments								Commitments
Financial	5 to 9 Years		$	298			$	130			$	282			$	145
Real Assets	3 to 7 Years		478				193				464				214
Distressed	5 to 9 Years		251				249				232				175
Private Credit	3 to 7 Years		303				181				299				190
Traditional	3 to 9 Years		910				239				895				285
Vintage	1 to 2 Years		9				—				11				1
Investment funds	Not Applicable		383				—				378				—
			$	2,632			$	992			$	2,561			$	1,010
In the first quarter of 2015, we redefined and regrouped certain alternative investment categories to better align with our management approach. The prior year amounts have been reclassified to conform to the current year presentation. 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 Assets		targeting investments related to hard physical assets such as real estate, infrastructure and natural resources
Distressed		targeting distressed corporate debt/credit and equity opportunities in the U.S.
Private Credit		targeting privately originated corporate debt investments including senior secured loans and subordinated bonds
Traditional		employing traditional private equity investment strategies such as buyout and growth equity globally
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								Valuation		Significant		Ranges
	31-Mar-15				31-Dec-14				Technique		Unobservable Inputs
GLB(1)	$	451			$	406			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
Three Months Ended	Available-for-Sale Debt Securities												Equity			Other				Other			GLB(1)
31-Mar-15	Foreign				Corporate				MBS				securities			investments				derivative
(in millions of U.S. dollars)					securities															instruments
Balance–Beginning of Period	$	22			$	187			$	15			$	2		$	2,719			$	4		$	406
Transfers into Level 3	—				1				—				—			—				—			—
Transfers out of Level 3	—				—				—				—			—				—			—
Change in Net Unrealized Gains (Losses) included in OCI	—				3				—				—			(20		)		—			—
Net Realized Gains/Losses	—				(3		)		—				—			—				—			45
Purchases	1				8				18				—			147				—			—
Sales	(1		)		(3		)		—				—			—				—			—
Settlements	—				(26		)		—				—			(57		)		—			—
Balance–End of Period	$	22			$	167			$	33			$	2		$	2,789			$	4		$	451
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	—			$	(2	)		$	—			$	—		$	—			$	—		$	45
(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 for additional information.
	Assets																								Liabilities
Three Months Ended	Available-for-Sale Debt Securities												Equity				Short-term investments				Other				GLB(1)
31-Mar-14	Foreign				Corporate				MBS				securities								investments
(in millions of U.S. dollars)					securities
Balance–Beginning of Period	$	44			$	166			$	8			$	4			$	7			$	2,440			$	193
Transfers into Level 3	—				4				—				—				—				—				—
Transfers out of Level 3	(18		)		(22		)		—				(2		)		(7		)		—				—
Change in Net Unrealized Gains (Losses) included in OCI	(1		)		—				—				1				—				41				—
Net Realized Gains/Losses	—				—				—				—				—				—				50
Purchases	2				15				—				1				—				200				—
Sales	(1		)		(6		)		—				(2		)		—				(1		)		—
Settlements	—				(6		)		—				—				—				(69		)		—
Balance–End of Period	$	26			$	151			$	8			$	2			$	—			$	2,611			$	243
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	—			$	—			$	—			$	—			$	—			$	—			$	50
(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 $483 million at March 31, 2014, and $427 million at December 31, 2013, which includes a fair value derivative adjustment of $243 million and $193 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-Mar-15	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	$	590			$	190			$	—			$	780			$	756
Foreign	—				873				—				873				816
Corporate securities	—				2,357				14				2,371				2,249
Mortgage-backed securities	—				1,983				—				1,983				1,907
States, municipalities, and political subdivisions	—				1,300				—				1,300				1,254
	590				6,703				14				7,307				6,982
Partially-owned insurance companies	—				—				590				590				590
Total assets	$	590			$	6,703			$	604			$	7,897			$	7,572
Liabilities:
Short-term debt	$	—			$	2,563			$	—			$	2,563			$	2,552
Long-term debt	—				4,575				—				4,575				4,157
Trust preferred securities	—				465				—				465				309
Total liabilities	$	—			$	7,603			$	—			$	7,603			$	7,018
31-Dec-14	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	$	659			$	191			$	—			$	850			$	832
Foreign	—				963				—				963				916
Corporate securities	—				2,408				15				2,423				2,323
Mortgage-backed securities	—				2,039				—				2,039				1,983
States, municipalities, and political subdivisions	—				1,314				—				1,314				1,277
	659				6,915				15				7,589				7,331
Partially-owned insurance companies	—				—				504				504				504
Total assets	$	659			$	6,915			$	519			$	8,093			$	7,835
Liabilities:
Short-term debt	$	—			$	2,571			$	—			$	2,571			$	2,552
Long-term debt	—				3,690				—				3,690				3,357
Trust preferred securities	—				462				—				462				309
Total liabilities	$	—			$	6,723			$	—			$	6,723			$	6,218

Assumed_life_reinsurance_progr

Assumed life reinsurance programs involving minimum benefit guarantees under annuity contracts	3 Months Ended
	Mar. 31, 2015
Reinsurance Disclosures [Abstract]
Assumed life reinsurance programs involving minimum benefit guarantees under annuity contracts	Assumed life reinsurance programs involving minimum benefit guarantees under variable 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.
		Three Months Ended
		31-Mar
	(in millions of U.S. dollars)	2015			2014
	GMDB
	Net premiums earned	$	16		$	19
	Policy benefits and other reserve adjustments	$	9		$	15
	GLB
	Net premiums earned	$	32		$	36
	Policy benefits and other reserve adjustments	12			9
	Net realized gains (losses)	(45		)	(50		)
	Loss recognized in Net income	$	(25	)	$	(23	)
	Less: Net cash received	28			33
	Net increase in liability	$	(53	)	$	(56	)
	Net realized gains (losses) in the table above include gains (losses) related to foreign exchange and fair value adjustments on insurance derivatives and exclude gains (losses) on S&P put options and futures held to partially offset the risk in the GLB reinsurance portfolio. Refer to Note 7 for additional information.
	At March 31, 2015 and December 31, 2014, the reported liability for GMDB reinsurance was $112 million and $111 million, respectively. At March 31, 2015 and December 31, 2014, the reported liability for GLB reinsurance was $716 million and $663 million, respectively, which includes a fair value derivative adjustment of $451 million and $406 million, respectively. 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 regularly reviewed by management and enhanced, as appropriate, based upon improvements in modeling assumptions and availability of updated information, such as market conditions and demographics of in-force annuities.

Debt

Debt	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Debt
	In March 2015, ACE INA Holdings Inc. issued $800 million of 3.15 percent senior notes due March 2025. These senior notes are redeemable at any time at ACE INA Holdings Inc.'s option subject to a “make-whole” premium (the present value of the remaining principal and interest discounted at the applicable U.S. Treasury rate plus 0.15 percent). The notes are also redeemable at par plus accrued and unpaid interest in the event of certain changes in tax law. These notes do not have the benefit of any sinking fund.  These senior unsecured notes 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.

Commitments_contingencies_and_

Commitments, contingencies, and guarantees	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments, contingencies, and guarantees	Commitments, contingencies, and guarantees
	a) Derivative instruments
	Foreign currency management
	As a global company, ACE entities transact business in multiple currencies. Our policy is to generally match assets, liabilities and required capital for each individual jurisdiction in local currency, which would include the use of derivatives discussed below. We do not hedge our net asset non-USD capital positions, however we do consider hedging for planned cross border transactions.
	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 securities that contain embedded derivatives. Investment derivative instruments are recorded in either Other assets (OA) or Accounts payable, accrued expenses, and other liabilities (AP), convertible bonds are recorded in Fixed maturities available for sale (FM AFS) and convertible equity securities are recorded in Equity securities (ES) in the consolidated balance sheets. 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 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.
	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-Mar-15							31-Dec-14
		Consolidated		Fair Value							Notional		Fair Value					Notional
		Balance Sheet									Value/							Value/
		Location									Payment							Payment
	(in millions of U.S. dollars)			Derivative Asset				Derivative (Liability)			Provision		Derivative Asset		Derivative (Liability)			Provision
	Investment and embedded derivative instruments
	Foreign currency forward contracts	OA / (AP)		$	15			$	(8	)	$	1,160	$	12	$	(7	)	$	1,329
	Cross-currency swaps	OA / (AP)		—				—			95		—		—			95
	Futures contracts on money market instruments	OA / (AP)		1				(1		)	4,355		—		—			2,467
	Options/Futures contracts on notes and bonds	OA / (AP)		5				(16		)	1,276		6		(29		)	1,636
	Convertible securities(1)	FM AFS / ES		298				—			272		291		—			267
	TBAs	FM AFS		31				—			30		—		—			—
				$	350			$	(25	)	$	7,188	$	309	$	(36	)	$	5,794
	Other derivative instruments
	Futures contracts on equities (2)	OA / (AP)		$	—			$	(3	)	$	1,340	$	—	$	(21	)	$	1,384
	Options on equity market indices (2)	OA / (AP)		1				—			250		2		—			250
	Other	OA / (AP)		—				(4		)	10		—		(4		)	10
				$	1			$	(7	)	$	1,600	$	2	$	(25	)	$	1,644
	GLB(3)	(AP) / (FPB)		$	—			$	(716	)	$	748	$	—	$	(663	)	$	675
	(1)	Includes fair value of embedded derivatives.
	(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 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.
	At March 31, 2015 and December 31, 2014, derivative liabilities of $4 million and $34 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.
	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. At March 31, 2015 and December 31, 2014, our securities lending payable was $1,034 million and $1,331 million, respectively, and our securities lending collateral was $1,033 million and $1,330 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. At both March 31, 2015 and December 31, 2014, our repurchase agreement obligations of $1,402 million were fully collateralized. 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:
		Three Months Ended
		31-Mar
	(in millions of U.S. dollars)	2015				2014
	Investment and embedded derivative instruments
	Foreign currency forward contracts	$	25			$	(3	)
	All other futures contracts and options	(29		)		(22		)
	Convertible securities(1)	5				—
	Total investment and embedded derivative instruments	$	1			$	(25	)
	GLB and other derivative instruments
	GLB(2)	$	(45	)		$	(48	)
	Futures contracts on equities(3)	(11		)		(17		)
	Options on equity market indices(3)	(1		)		(2		)
	Other	—				(2		)
	Total GLB and other derivative instruments	$	(57	)		$	(69	)
		$	(56	)		$	(94	)
	(1)	Includes embedded derivatives.
	(2)	Excludes foreign exchange gains (losses) related to GLB.
	(3)	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 as discussed above.
	(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, an increase in 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, an increase in 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, ACE may enter into crop derivative contracts to protect underwriting results in the event of a significant decline in commodity prices. Also included within Other are certain life insurance products that meet the definition of a derivative instrument for accounting purposes.
(iii) Convertible security investments
A convertible security is a debt instrument or preferred stock that can be converted into a predetermined amount of the issuer’s equity. The convertible option is an embedded derivative within the host instruments which are classified in the investment portfolio as either available for sale or as an equity security. ACE purchases convertible securities 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 an 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) Other investments
At March 31, 2015, included in Other investments in the consolidated balance sheet are investments in limited partnerships and partially-owned investment companies with a carrying value of $2.2 billion. In connection with these investments, we have commitments that may require funding of up to $992 million over the next several years.
c) Taxation
At March 31, 2015, $23 million of unrecognized tax benefits remains outstanding. 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. With few exceptions, ACE is no longer subject to state and local or non-U.S. income tax examinations for years before 2005.
d) 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.

Shareholders_equity

Shareholders' equity	3 Months Ended
	Mar. 31, 2015
Stockholders' Equity Note [Abstract]
Shareholders' equity	Shareholders’ equity
	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 consolidated financial statements. Under Swiss corporate law, dividends, including distributions through a reduction in par value (par value reduction) or from legal reserves, must be stated in Swiss francs though dividend payments are made by ACE in U.S. dollars.
	At our May 2013 annual general meeting, our shareholders approved an annual dividend for the following year of $2.04 per share, payable in four quarterly installments of $0.51 per share after the annual general meeting 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 April 17, 2014) that had been earlier approved at our 2013 annual general meeting. The $0.12 per share increase for each installment was distributed from capital contribution reserves (Additional paid-in capital), a subaccount of legal reserves, and transferred to free reserves (Retained earnings) for payment, while the existing $0.51 per share was distributed by way of a par value reduction.
	At our May 2014 annual general meeting, our shareholders approved an annual dividend for the following year of $2.60 per share, payable in four quarterly installments of $0.65 per share after the annual general meeting in the form of a distribution by way of a par value reduction.
	The following table presents dividend distributions per Common Share in Swiss francs (CHF) and U.S. dollars (USD):
		Three Months Ended
		31-Mar
		2015					2014
		CHF		USD			CHF			USD
	Dividends – par value reduction	0.62		$	0.65		0.45			$	0.51
	Dividends – distributed from capital contribution reserves	—		—			0.2			0.24
	Total dividend distributions per common share	0.62		$	0.65		0.65			$	0.75
	Par value reductions have been reflected as such through Common Shares in the consolidated statements of shareholders' equity and had the effect of reducing par value per Common Share to CHF 24.15 at March 31, 2015.
	Common Shares in treasury are used principally for issuance upon the exercise of employee stock options, grants of restricted stock, and purchases under the Employee Stock Purchase Plan (ESPP). At March 31, 2015, 15,747,650 Common Shares remain in treasury after net shares redeemed under employee share-based compensation plans.
	ACE Limited securities repurchase authorization
	On November 21, 2013, the Board of Directors (Board) announced authorization of a share repurchase program of up to $2.0 billion of ACE's Common Shares through December 31, 2014.
	On November 24, 2014, the Board announced authorization of a share repurchase program of $1.5 billion of ACE's Common Shares for the period January 1, 2015 through December 31, 2015 to replace the November 2013 authorization when it expired on December 31, 2014.
	The following table presents repurchases of ACE's Common Shares conducted in a series of open market transactions under the Board authorizations:
	(in millions of U.S. dollars, except share data)	Three Months Ended						April 1, 2015 through April 28, 2015
		March 31
		2015			2014
	Number of shares repurchased	3,027,463			3,487,882			1,351,820
	Dollar value of shares repurchased	$	340		$	332		$	149
	Repurchase authorization remaining at end of period	$	1,160		$	1,612		$	1,011

Sharebased_compensation

Share-based compensation	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation	Share-based compensation
	The ACE Limited 2004 Long-Term Incentive Plan (the 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 typically vest in equal annual installments over the vesting period, which is also the requisite service period. On February 26, 2015, ACE granted 1,891,195 stock options with a weighted-average grant date fair value of $18.49 each. The fair value of the options issued is estimated on the grant date using the Black-Scholes option pricing model.
	The 2004 LTIP also permits grants of 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 grant date. On February 26, 2015, ACE granted 1,278,250 restricted stock awards and 290,475 restricted stock units to employees and officers with a grant date fair value of $114.78 each. Each restricted stock unit represents our obligation to deliver to the holder one Common Share upon vesting.

Segment_information

Segment information	3 Months Ended
	Mar. 31, 2015
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.
	Corporate includes the results of ACE’s non-insurance subsidiaries, including ACE Limited, ACE Group Management and Holdings Ltd., and ACE INA Holdings, Inc.  Corporate results consist primarily of interest expense, corporate staff expenses and other expenses not attributable to specific reportable segments, and intersegment eliminations.
	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 on crop derivatives as a component of underwriting income. For example, for the three months ended March 31, 2014, underwriting loss in our Insurance – North American Agriculture segment was $31 million. This amount includes $2 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 the three months ended March 31, 2015, Life underwriting income of $77 million includes Net investment income of $66 million and gains from fair value changes in separate account assets of $11 million.
	The following tables present the Statement of Operations by segment:
	For the Three Months Ended March 31, 2015	Insurance – North American P&C			Insurance – North American Agriculture			Insurance –			Global			Life			Corporate			ACE
								Overseas			Reinsurance									Consolidated
	(in millions of U.S. dollars)							General
	Net premiums written	$	1,430		$	88		$	1,794		$	273		$	491		$	—		$	4,076
	Net premiums earned	1,526			64			1,637			226			474			—			3,927
	Losses and loss expenses	1,035			22			814			99			152			—			2,122
	Policy benefits	—			—			—			—			142			—			142
	Policy acquisition costs	161			(4		)	389			54			107			—			707
	Administrative expenses	171			(1		)	256			12			73			43			554
	Underwriting income (loss)	159			47			178			61			—			(43		)	402
	Net investment income	263			6			138			75			66			3			551
	Net realized gains (losses) including OTTI	(6		)	—			(10		)	(11		)	(59		)	(3		)	(89		)
	Interest expense	2			—			1			1			1			63			68
	Other (income) expense:
	(Gains) losses from fair value changes in separate account assets	—			—			—			—			(11		)	—			(11		)
	Other	(7		)	8			17			(5		)	(12		)	5			6
	Income tax expense (benefit)	80			10			52			8			9			(39		)	120
	Net income (loss)	$	341		$	35		$	236		$	121		$	20		$	(72	)	$	681
	For the Three Months Ended March 31, 2014	Insurance – North American P&C			Insurance – North American Agriculture			Insurance –			Global			Life			Corporate			ACE
								Overseas			Reinsurance									Consolidated
	(in millions of U.S. dollars)							General
	Net premiums written	$	1,418		$	194		$	1,771		$	308		$	494		$	—		$	4,185
	Net premiums earned	1,487			103			1,612			284			484			—			3,970
	Losses and loss expenses	940			126			817			126			151			1			2,161
	Policy benefits	—			—			—			—			114			—			114
	Policy acquisition costs	159			5			386			67			111			—			728
	Administrative expenses	161			1			250			14			68			41			535
	Underwriting income (loss)	227			(29		)	159			77			40			(42		)	432
	Net investment income	270			7			132			77			64			3			553
	Net realized gains (losses) including OTTI	(9		)	(2		)	(10		)	(8		)	(76		)	1			(104		)
	Interest expense	3			—			1			1			3			63			71
	Other (income) expense:
	(Gains) losses from fair value changes in separate account assets	—			—			—			—			6			—			6
	Other	(20		)	8			(6		)	(19		)	7			7			(23		)
	Income tax expense (benefit)	83			(7		)	37			10			10			(40		)	93
	Net income (loss)	$	422		$	(25	)	$	249		$	154		$	2		$	(68	)	$	734
	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 Three Months Ended March 31, 2015							Health
	Insurance – North American P&C	$	410		$	1,015		$	101		$	1,526
	Insurance – North American Agriculture	64			—			—			64
	Insurance – Overseas General	728			382			527			1,637
	Global Reinsurance	117			109			—			226
	Life	—			—			474			474
		$	1,319		$	1,506		$	1,102		$	3,927
	For the Three Months Ended March 31, 2014
	Insurance – North American P&C	$	405		$	981		$	101		$	1,487
	Insurance – North American Agriculture	103			—			—			103
	Insurance – Overseas General	693			369			550			1,612
	Global Reinsurance	154			130			—			284
	Life	—			—			484			484
		$	1,355		$	1,480		$	1,135		$	3,970

Earnings_per_share

Earnings per share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings per share	Earnings per share
		Three Months Ended
		31-Mar
	(in millions of U.S. dollars, except share and per share data)	2015		2014
	Numerator:
	Net income	$	681	$	734
	Denominator:
	Denominator for basic earnings per share:
	Weighted-average shares outstanding	328,212,376		338,869,562
	Denominator for diluted earnings per share:
	Share-based compensation plans	3,480,344		3,171,174
	Weighted-average shares outstanding and assumed conversions	331,692,720		342,040,736
	Basic earnings per share	$	2.08	$	2.16
	Diluted earnings per share	$	2.05	$	2.14
	Potential anti-dilutive share conversions	715,148		657,182
	Excluded from weighted-average shares outstanding and assumed conversions is the impact of securities that would have been anti-dilutive during the respective periods.

Information_provided_in_connec

Information provided in connection with outstanding debt of subsidiaries	3 Months Ended
	Mar. 31, 2015
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 March 31, 2015 and December 31, 2014, and for the three months ended March 31, 2015 and 2014 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. Condensed consolidating financial information of the Parent Guarantor and Subsidiary Issuer are presented on the equity method of accounting. The revenues and expenses and cash flows of the subsidiaries of the Subsidiary Issuer are presented in the Other ACE Limited Subsidiaries column on a combined basis.
	Condensed Consolidating Balance Sheet at March 31, 2015
	(in millions of U.S. dollars)	ACE			ACE INA			Other ACE			Consolidating			ACE Limited
		Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		(Parent			(Subsidiary			Subsidiaries
		Guarantor)			Issuer)
	Assets
	Investments	$	31		$	10		$	63,853		$	—		$	63,894
	Cash(1)	2			366			658			(78		)	948
	Insurance and reinsurance balances receivable	—			—			5,746			(720		)	5,026
	Reinsurance recoverable on losses and loss expenses	—			—			20,292			(8,704		)	11,588
	Reinsurance recoverable on policy benefits	—			—			1,171			(956		)	215
	Value of business acquired	—			—			440			—			440
	Goodwill and other intangible assets	—			—			5,516			—			5,516
	Investments in subsidiaries	29,798			18,767			—			(48,565		)	—
	Due from subsidiaries and affiliates, net	233			—			—			(233		)	—
	Other assets	4			291			14,088			(3,612		)	10,771
	Total assets	$	30,068		$	19,434		$	111,764		$	(62,868	)	$	98,398
	Liabilities
	Unpaid losses and loss expenses	$	—		$	—		$	45,518		$	(8,192	)	$	37,326
	Unearned premiums	—			—			9,912			(1,730		)	8,182
	Future policy benefits	—			—			5,700			(956		)	4,744
	Due to subsidiaries and affiliates, net	—			103			130			(233		)	—
	Affiliated notional cash pooling programs(1)	78			—			—			(78		)	—
	Short-term debt	—			1,150			1,402			—			2,552
	Long-term debt	—			4,145			12			—			4,157
	Trust preferred securities	—			309			—			—			309
	Other liabilities	288			1,434			12,818			(3,114		)	11,426
	Total liabilities	366			7,141			75,492			(14,303		)	68,696
	Total shareholders’ equity	29,702			12,293			36,272			(48,565		)	29,702
	Total liabilities and shareholders’ equity	$	30,068		$	19,434		$	111,764		$	(62,868	)	$	98,398
	(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
	Condensed Consolidating Balance Sheet at December 31, 2014
	(in millions of U.S. dollars)	ACE			ACE INA			Other ACE			Consolidating			ACE Limited
		Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		(Parent			(Subsidiary			Subsidiaries
		Guarantor)			Issuer)
	Assets
	Investments	$	30		$	225		$	62,649		$	—		$	62,904
	Cash(1)	—			1			1,209			(555		)	655
	Insurance and reinsurance balances receivable	—			—			6,178			(752		)	5,426
	Reinsurance recoverable on losses and loss expenses	—			—			20,992			(9,000		)	11,992
	Reinsurance recoverable on policy benefits	—			—			1,194			(977		)	217
	Value of business acquired	—			—			466			—			466
	Goodwill and other intangible assets	—			—			5,724			—			5,724
	Investments in subsidiaries	29,497			18,762			—			(48,259		)	—
	Due from subsidiaries and affiliates, net	583			—			—			(583		)	—
	Other assets	4			295			14,196			(3,631		)	10,864
	Total assets	$	30,114		$	19,283		$	112,608		$	(63,757	)	$	98,248
	Liabilities
	Unpaid losses and loss expenses	$	—		$	—		$	46,770		$	(8,455	)	$	38,315
	Unearned premiums	—			—			9,958			(1,736		)	8,222
	Future policy benefits	—			—			5,731			(977		)	4,754
	Due to subsidiaries and affiliates, net	—			422			161			(583		)	—
	Affiliated notional cash pooling programs(1)	246			309			—			(555		)	—
	Short-term debt	—			1,150			1,402			—			2,552
	Long-term debt	—			3,345			12			—			3,357
	Trust preferred securities	—			309			—			—			309
	Other liabilities	281			1,404			12,659			(3,192		)	11,152
	Total liabilities	527			6,939			76,693			(15,498		)	68,661
	Total shareholders’ equity	29,587			12,344			35,915			(48,259		)	29,587
	Total liabilities and shareholders’ equity	$	30,114		$	19,283		$	112,608		$	(63,757	)	$	98,248
	(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2014, 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 Three Months Ended March 31, 2015	ACE			ACE INA			Other ACE			Consolidating			ACE
	Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Limited
	(Parent			(Subsidiary			Subsidiaries						Consolidated
(in millions of U.S. dollars)	Guarantor)			Issuer)
Net premiums written	$	—		$	—		$	4,076		$	—		$	4,076
Net premiums earned	—			—			3,927			—			3,927
Net investment income	1			1			549			—			551
Equity in earnings of subsidiaries	648			204			—			(852		)	—
Net realized gains (losses) including OTTI	—			—			(89		)	—			(89		)
Losses and loss expenses	—			—			2,122			—			2,122
Policy benefits	—			—			142			—			142
Policy acquisition costs and administrative expenses	14			6			1,241			—			1,261
Interest (income) expense	(8		)	69			7			—			68
Other (income) expense	(41		)	(3		)	39			—			(5		)
Income tax expense (benefit)	3			(26		)	143			—			120
Net income	$	681		$	159		$	693		$	(852	)	$	681
Comprehensive income	$	642		$	24		$	654		$	(678	)	$	642
Condensed Consolidating Statements of Operations and Comprehensive Income
For the Three Months Ended March 31, 2014	ACE			ACE INA			Other ACE			Consolidating			ACE
	Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Limited
	(Parent			(Subsidiary			Subsidiaries						Consolidated
(in millions of U.S. dollars)	Guarantor)			Issuer)
Net premiums written	$	—		$	—		$	4,185		$	—		$	4,185
Net premiums earned	—			—			3,970			—			3,970
Net investment income	—			—			553			—			553
Equity in earnings of subsidiaries	702			180			—			(882		)	—
Net realized gains (losses) including OTTI	—			(1		)	(103		)	—			(104		)
Losses and loss expenses	—			—			2,161			—			2,161
Policy benefits	—			—			114			—			114
Policy acquisition costs and administrative expenses	17			6			1,240			—			1,263
Interest (income) expense	(10		)	71			10			—			71
Other (income) expense	(42		)	14			11			—			(17		)
Income tax expense (benefit)	3			(30		)	120			—			93
Net income	$	734		$	118		$	764		$	(882	)	$	734
Comprehensive income	$	1,108		$	266		$	1,138		$	(1,404	)	$	1,108
Condensed Consolidating Statement of Cash Flows
Three Months Ended March 31, 2015	ACE			ACE INA			Other ACE			Consolidating			ACE
	Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Limited
	(Parent			(Subsidiary			Subsidiaries						Consolidated
(in millions of U.S. dollars)	Guarantor)			Issuer)
Net cash flows from operating activities	$	48		$	4		$	1,023		$	—		$	1,075
Cash flows from investing activities
Purchases of fixed maturities available for sale	—			—			(4,336		)	—			(4,336		)
Purchases of fixed maturities held to maturity	—			—			(21		)	—			(21		)
Purchases of equity securities	—			—			(39		)	—			(39		)
Sales of fixed maturities available for sale	—			—			2,002			—			2,002
Sales of equity securities	—			—			28			—			28
Maturities and redemptions of fixed maturities available for sale	—			—			1,481			—			1,481
Maturities and redemptions of fixed maturities held to maturity	—			—			324			—			324
Net change in short-term investments	—			216			(471		)	—			(255		)
Net derivative instruments settlements	—			—			(51		)	—			(51		)
Other	—			—			(153		)	—			(153		)
Net cash flows from (used for) investing activities	—			216			(1,236		)	—			(1,020		)
Cash flows from financing activities
Dividends paid on Common Shares	(214		)	—			—			—			(214		)
Common Shares repurchased	—			—			(347		)	—			(347		)
Proceeds from issuance of long-term debt	—			800			—			—			800
Proceeds from issuance of short-term debt	—			—			477			—			477
Repayment of short-term debt	—			—			(477		)	—			(477		)
Proceeds from share-based compensation plans, including windfall tax benefits	—			—			39			—			39
Advances (to) from affiliates	336			(340		)	4			—			—
Net payments to affiliated notional cash pooling programs(1)	(168		)	(309		)	—			477			—
Policyholder contract deposits	—			—			101			—			101
Policyholder contract withdrawals	—			—			(40		)	—			(40		)
Other	—			(6		)	—			—			(6		)
Net cash flows (used for) from financing activities	(46		)	145			(243		)	477			333
Effect of foreign currency rate changes on cash and cash equivalents	—			—			(95		)	—			(95		)
Net increase (decrease) in cash	2			365			(551		)	477			293
Cash – beginning of period(1)	—			1			1,209			(555		)	655
Cash – end of period(1)	$	2		$	366		$	658		$	(78	)	$	948
(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015 and December 31, 2014, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condensed Consolidating Statement of Cash Flows
Three Months Ended March 31, 2014	ACE			ACE INA			Other ACE			Consolidating			ACE
	Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Limited
	(Parent			(Subsidiary			Subsidiaries						Consolidated
(in millions of U.S. dollars)	Guarantor)			Issuer)
Net cash flows from (used for) operating activities	$	57		$	(13	)	$	1,206		$	—		$	1,250
Cash flows from investing activities
Purchases of fixed maturities available for sale	—			—			(3,522		)	—			(3,522		)
Purchases of fixed maturities held to maturity	—			—			(30		)	—			(30		)
Purchases of equity securities	—			—			(37		)	—			(37		)
Sales of fixed maturities available for sale	—			—			2,208			—			2,208
Sales of equity securities	—			—			27			—			27
Maturities and redemptions of fixed maturities available for sale	—			—			1,550			—			1,550
Maturities and redemptions of fixed maturities held to maturity	—			—			212			—			212
Net change in short-term investments	—			(8		)	(757		)	—			(765		)
Net derivative instruments settlements	—			(9		)	(87		)	—			(96		)
Other	—			(3		)	(47		)	—			(50		)
Net cash flows used for investing activities	—			(20		)	(483		)	—			(503		)
Cash flows from financing activities
Dividends paid on Common Shares	(214		)	—			—			—			(214		)
Common Shares repurchased	—			—			(335		)	—			(335		)
Proceeds from issuance of short-term debt	—			—			426			—			426
Repayment of short-term debt	—			—			(426		)	—			(426		)
Proceeds from share-based compensation plans, including windfall tax benefits	—			—			40			—			40
Advances (to) from affiliates	367			(367		)	—			—			—
Net proceeds from (payments to) affiliated notional cash pooling programs(1)	(185		)	385			—			(200		)	—
Policyholder contract deposits	—			—			51			—			51
Policyholder contract withdrawals	—			—			(14		)	—			(14		)
Net cash flows (used for) from financing activities	(32		)	18			(258		)	(200		)	(472		)
Effect of foreign currency rate changes on cash and cash equivalents	—			—			(7		)	—			(7		)
Net increase (decrease) in cash	25			(15		)	458			(200		)	268
Cash – beginning of period(1)	—			16			748			(185		)	579
Cash – end of period(1)	$	25		$	1		$	1,206		$	(385	)	$	847
(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2014 and December 31, 2013, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

General_Policies

General (Policies)	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of presentation	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 10 for additional information.
	The interim unaudited 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, including internal reinsurance transactions, have been eliminated.
	The results of operations and cash flows for any interim period are not necessarily indicative of the results for the full year. These consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in our 2014 Form 10-K.
New Accounting Pronouncements, Policy [Policy Text Block]	b) Accounting guidance not yet adopted
	Presentation of Debt Issuance Costs
	In April 2015, the Financial Accounting Standards Board issued new guidance related to the accounting for debt issuance costs.  The new guidance requires presentation of debt issuance costs in the balance sheet as a deduction from the carrying amount of the related debt liability instead of a deferred charge.  The new guidance requires retrospective adoption and is effective for interim and annual reporting periods beginning after December 15, 2015, with early adoption permitted. The adoption of this guidance will not have any effect on our results of operations and financial condition.

Investments_Tables

Investments (Tables)	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Schedule Of Amortized Cost And Fair Value Of Fixed Maturities And Related OTTI Recognized In AOCI
	31-Mar-15	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	$	2,793		$	98		$	(2	)	$	2,889		$	—
	Foreign	14,262			761			(76		)	14,947			—
	Corporate securities	17,259			834			(94		)	17,999			(6		)
	Mortgage-backed securities	10,459			362			(13		)	10,808			(1		)
	States, municipalities, and political subdivisions	3,611			160			(4		)	3,767			—
		$	48,384		$	2,215		$	(189	)	$	50,410		$	(7	)
	Held to maturity
	U.S. Treasury and agency	$	756		$	24		$	—		$	780		$	—
	Foreign	816			57			—			873			—
	Corporate securities	2,249			122			—			2,371			—
	Mortgage-backed securities	1,907			77			(1		)	1,983			—
	States, municipalities, and political subdivisions	1,254			47			(1		)	1,300			—
		$	6,982		$	327		$	(2	)	$	7,307		$	—
	31-Dec-14	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	$	2,741		$	87		$	(8	)	$	2,820		$	—
	Foreign	14,703			629			(90		)	15,242			—
	Corporate securities	16,897			704			(170		)	17,431			(7		)
	Mortgage-backed securities	10,011			304			(29		)	10,286			(1		)
	States, municipalities, and political subdivisions	3,474			147			(5		)	3,616			—
		$	47,826		$	1,871		$	(302	)	$	49,395		$	(8	)
	Held to maturity
	U.S. Treasury and agency	$	832		$	20		$	(2	)	$	850		$	—
	Foreign	916			47			—			963			—
	Corporate securities	2,323			102			(2		)	2,423			—
	Mortgage-backed securities	1,983			57			(1		)	2,039			—
	States, municipalities, and political subdivisions	1,277			40			(3		)	1,314			—
		$	7,331		$	266		$	(8	)	$	7,589		$	—
Schedule Of Fixed Maturities By Contractual Maturity
					31-Mar						31-Dec
					2015						2014
	(in millions of U.S. dollars)	Amortized Cost			Fair Value			Amortized Cost			Fair Value
	Available for sale
	Due in 1 year or less	$	2,021		$	2,042		$	2,187		$	2,206
	Due after 1 year through 5 years	16,209			16,735			15,444			15,857
	Due after 5 years through 10 years	15,047			15,649			15,663			16,089
	Due after 10 years	4,648			5,176			4,521			4,957
		37,925			39,602			37,815			39,109
	Mortgage-backed securities	10,459			10,808			10,011			10,286
		$	48,384		$	50,410		$	47,826		$	49,395
	Held to maturity
	Due in 1 year or less	$	318		$	321		$	353		$	355
	Due after 1 year through 5 years	2,594			2,706			2,603			2,693
	Due after 5 years through 10 years	1,214			1,270			1,439			1,489
	Due after 10 years	949			1,027			953			1,013
		5,075			5,324			5,348			5,550
	Mortgage-backed securities	1,907			1,983			1,983			2,039
		$	6,982		$	7,307		$	7,331		$	7,589
Schedule Of Cost And Fair Value Of Equity Securities
		31-Mar			31-Dec
	(in millions of U.S. dollars)	2015			2014
	Cost	$	447		$	440
	Gross unrealized appreciation	99			83
	Gross unrealized depreciation	(10		)	(13		)
	Fair value	$	536		$	510
Schedule Of Net Realized Gains (Losses) And The Losses Included In Net Realized Gains (Losses) And OCI
		Three Months Ended
		31-Mar
	(in millions of U.S. dollars)	2015			2014
	Fixed maturities:
	OTTI on fixed maturities, gross	$	(13	)	$	(6	)
	OTTI on fixed maturities recognized in OCI (pre-tax)	—			1
	OTTI on fixed maturities, net	(13		)	(5		)
	Gross realized gains excluding OTTI	44			36
	Gross realized losses excluding OTTI	(35		)	(20		)
	Total fixed maturities	(4		)	11
	Equity securities:
	OTTI on equity securities	—			(6		)
	Gross realized gains excluding OTTI	3			2
	Gross realized losses excluding OTTI	(2		)	(1		)
	Total equity securities	1			(5		)
	OTTI on other investments	—			—
	Foreign exchange losses	(31		)	(9		)
	Investment and embedded derivative instruments	1			(25		)
	Fair value adjustments on insurance derivative	(45		)	(48		)
	S&P put options and futures	(12		)	(19		)
	Other derivative instruments	—			(2		)
	Other	1			(7		)
	Net realized gains (losses)	$	(89	)	$	(104	)
Schedule Of Roll-Forward Of Pre-Tax Credit Losses Related To Fixed Maturities For Which A Portion Of OTTI Was Recognized In OCI
		Three Months Ended
		31-Mar
	(in millions of U.S. dollars)	2015			2014
	Balance of credit losses related to securities still held – beginning of period	$	28		$	37
	Additions where no OTTI was previously recorded	3			2
	Additions where an OTTI was previously recorded	1			2
	Reductions for securities sold during the period	(10		)	(6		)
	Balance of credit losses related to securities still held – end of period	$	22		$	35
Schedule Of 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-Mar-15	Fair Value			Gross			Fair Value			Gross			Fair Value			Gross
					Unrealized						Unrealized						Unrealized
	(in millions of U.S. dollars)				Loss						Loss						Loss
	U.S. Treasury and agency	$	443		$	(1	)	$	141		$	(1	)	$	584		$	(2	)
	Foreign	1,747			(64		)	317			(12		)	2,064			(76		)
	Corporate securities	2,140			(79		)	500			(15		)	2,640			(94		)
	Mortgage-backed securities	1,301			(6		)	560			(8		)	1,861			(14		)
	States, municipalities, and political subdivisions	462			(3		)	89			(2		)	551			(5		)
	Total fixed maturities	6,093			(153		)	1,607			(38		)	7,700			(191		)
	Equity securities	68			(10		)	—			—			68			(10		)
	Other investments	92			(6		)	—			—			92			(6		)
	Total	$	6,253		$	(169	)	$	1,607		$	(38	)	$	7,860		$	(207	)
		0 – 12 Months						Over 12 Months						Total
	31-Dec-14	Fair Value			Gross			Fair Value			Gross			Fair Value			Gross
					Unrealized						Unrealized						Unrealized
	(in millions of U.S. dollars)				Loss						Loss						Loss
	U.S. Treasury and agency	$	350		$	(1	)	$	666		$	(9	)	$	1,016		$	(10	)
	Foreign	2,262			(75		)	375			(15		)	2,637			(90		)
	Corporate securities	4,684			(150		)	738			(22		)	5,422			(172		)
	Mortgage-backed securities	704			(2		)	1,663			(28		)	2,367			(30		)
	States, municipalities, and political subdivisions	458			(3		)	490			(5		)	948			(8		)
	Total fixed maturities	8,458			(231		)	3,932			(79		)	12,390			(310		)
	Equity securities	101			(13		)	—			—			101			(13		)
	Total	$	8,559		$	(244	)	$	3,932		$	(79	)	$	12,491		$	(323	)
Schedule Of Components Of Restricted Assets
		31-Mar			31-Dec
	(in millions of U.S. dollars)	2015			2014
	Trust funds	$	11,132		$	10,838
	Deposits with non-U.S. regulatory authorities	2,296			2,305
	Assets pledged under repurchase agreements	1,459			1,431
	Deposits with U.S. regulatory authorities	1,336			1,345
	Other pledged assets	446			457
		$	16,669		$	16,376

Fair_value_measurements_Tables

Fair value measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Financial Instruments Measured At Fair Value On A Recurring Basis
	31-Mar-15	Level 1				Level 2				Level 3				Total
	(in millions of U.S. dollars)
	Assets:
	Fixed maturities available for sale
	U.S. Treasury and agency	$	1,747			$	1,142			$	—			$	2,889
	Foreign	—				14,925				22				14,947
	Corporate securities	—				17,832				167				17,999
	Mortgage-backed securities	—				10,775				33				10,808
	States, municipalities, and political subdivisions	—				3,767				—				3,767
		1,747				48,441				222				50,410
	Equity securities	518				16				2				536
	Short-term investments	1,469				1,067				—				2,536
	Other investments	364				277				2,789				3,430
	Securities lending collateral	—				1,033				—				1,033
	Investment derivative instruments	21				—				—				21
	Other derivative instruments	—				1				—				1
	Separate account assets	1,488				86				—				1,574
	Total assets measured at fair value	$	5,607			$	50,921			$	3,013			$	59,541
	Liabilities:
	Investment derivative instruments	$	25			$	—			$	—			$	25
	Other derivative instruments	3				—				4				7
	GLB(1)	—				—				451				451
	Total liabilities measured at fair value	$	28			$	—			$	455			$	483
	(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 for additional information.
	December 31, 2014	Level 1				Level 2				Level 3				Total
	(in millions of U.S. dollars)
	Assets:
	Fixed maturities available for sale
	U.S. Treasury and agency	$	1,680			$	1,140			$	—			$	2,820
	Foreign	—				15,220				22				15,242
	Corporate securities	—				17,244				187				17,431
	Mortgage-backed securities	—				10,271				15				10,286
	States, municipalities, and political subdivisions	—				3,616				—				3,616
		1,680				47,491				224				49,395
	Equity securities	492				16				2				510
	Short-term investments	1,183				1,139				—				2,322
	Other investments	370				257				2,719				3,346
	Securities lending collateral	—				1,330				—				1,330
	Investment derivative instruments	18				—				—				18
	Other derivative instruments	—				2				—				2
	Separate account assets	1,400				90				—				1,490
	Total assets measured at fair value	$	5,143			$	50,325			$	2,945			$	58,413
	Liabilities:
	Investment derivative instruments	$	36			$	—			$	—			$	36
	Other derivative instruments	21				—				4				25
	GLB(1)	—				—				406				406
	Total liabilities measured at fair value	$	57			$	—			$	410			$	467
	(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 for additional information.
Fair Value And Maximum Future Funding Commitments Related To Investments
								31-Mar								31-Dec
		Expected						2015								2014
		Liquidation
	(in millions of U.S. dollars)	Period of Underlying Assets		Fair				Maximum				Fair				Maximum
				Value				Future Funding				Value				Future Funding
								Commitments								Commitments
	Financial	5 to 9 Years		$	298			$	130			$	282			$	145
	Real Assets	3 to 7 Years		478				193				464				214
	Distressed	5 to 9 Years		251				249				232				175
	Private Credit	3 to 7 Years		303				181				299				190
	Traditional	3 to 9 Years		910				239				895				285
	Vintage	1 to 2 Years		9				—				11				1
	Investment funds	Not Applicable		383				—				378				—
				$	2,632			$	992			$	2,561			$	1,010
Schedule Of Significant Unobservable Inputs Used In Level 3 Liability Valuations
	(in millions of U.S. dollars, except for percentages)	Fair Value								Valuation		Significant		Ranges
		31-Mar-15				31-Dec-14				Technique		Unobservable Inputs
	GLB(1)	$	451			$	406			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
		Assets																						Liabilities
	Three Months Ended	Available-for-Sale Debt Securities												Equity			Other				Other			GLB(1)
	31-Mar-15	Foreign				Corporate				MBS				securities			investments				derivative
	(in millions of U.S. dollars)					securities															instruments
	Balance–Beginning of Period	$	22			$	187			$	15			$	2		$	2,719			$	4		$	406
	Transfers into Level 3	—				1				—				—			—				—			—
	Transfers out of Level 3	—				—				—				—			—				—			—
	Change in Net Unrealized Gains (Losses) included in OCI	—				3				—				—			(20		)		—			—
	Net Realized Gains/Losses	—				(3		)		—				—			—				—			45
	Purchases	1				8				18				—			147				—			—
	Sales	(1		)		(3		)		—				—			—				—			—
	Settlements	—				(26		)		—				—			(57		)		—			—
	Balance–End of Period	$	22			$	167			$	33			$	2		$	2,789			$	4		$	451
	Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	—			$	(2	)		$	—			$	—		$	—			$	—		$	45
	(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 for additional information.
		Assets																								Liabilities
	Three Months Ended	Available-for-Sale Debt Securities												Equity				Short-term investments				Other				GLB(1)
	31-Mar-14	Foreign				Corporate				MBS				securities								investments
	(in millions of U.S. dollars)					securities
	Balance–Beginning of Period	$	44			$	166			$	8			$	4			$	7			$	2,440			$	193
	Transfers into Level 3	—				4				—				—				—				—				—
	Transfers out of Level 3	(18		)		(22		)		—				(2		)		(7		)		—				—
	Change in Net Unrealized Gains (Losses) included in OCI	(1		)		—				—				1				—				41				—
	Net Realized Gains/Losses	—				—				—				—				—				—				50
	Purchases	2				15				—				1				—				200				—
	Sales	(1		)		(6		)		—				(2		)		—				(1		)		—
	Settlements	—				(6		)		—				—				—				(69		)		—
	Balance–End of Period	$	26			$	151			$	8			$	2			$	—			$	2,611			$	243
	Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	—			$	—			$	—			$	—			$	—			$	—			$	50
	(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 $483 million at March 31, 2014, and $427 million at December 31, 2013, which includes a fair value derivative adjustment of $243 million and $193 million, respectively.
Carrying Values And Fair Values Of Financial Instruments Not Measured At Fair Value
	31-Mar-15	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	$	590			$	190			$	—			$	780			$	756
	Foreign	—				873				—				873				816
	Corporate securities	—				2,357				14				2,371				2,249
	Mortgage-backed securities	—				1,983				—				1,983				1,907
	States, municipalities, and political subdivisions	—				1,300				—				1,300				1,254
		590				6,703				14				7,307				6,982
	Partially-owned insurance companies	—				—				590				590				590
	Total assets	$	590			$	6,703			$	604			$	7,897			$	7,572
	Liabilities:
	Short-term debt	$	—			$	2,563			$	—			$	2,563			$	2,552
	Long-term debt	—				4,575				—				4,575				4,157
	Trust preferred securities	—				465				—				465				309
	Total liabilities	$	—			$	7,603			$	—			$	7,603			$	7,018
	31-Dec-14	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	$	659			$	191			$	—			$	850			$	832
	Foreign	—				963				—				963				916
	Corporate securities	—				2,408				15				2,423				2,323
	Mortgage-backed securities	—				2,039				—				2,039				1,983
	States, municipalities, and political subdivisions	—				1,314				—				1,314				1,277
		659				6,915				15				7,589				7,331
	Partially-owned insurance companies	—				—				504				504				504
	Total assets	$	659			$	6,915			$	519			$	8,093			$	7,835
	Liabilities:
	Short-term debt	$	—			$	2,571			$	—			$	2,571			$	2,552
	Long-term debt	—				3,690				—				3,690				3,357
	Trust preferred securities	—				462				—				462				309
	Total liabilities	$	—			$	6,723			$	—			$	6,723			$	6,218

Assumed_life_reinsurance_progr1

Assumed life reinsurance programs involving minimum benefit guarantees under annuity contracts (Tables)	3 Months Ended
	Mar. 31, 2015
Reinsurance Disclosures [Abstract]
Schedule Of Guaranteed Minimum Death Benefits And Guaranteed Minimum Income Benefits Income And Expense
		Three Months Ended
		31-Mar
	(in millions of U.S. dollars)	2015			2014
	GMDB
	Net premiums earned	$	16		$	19
	Policy benefits and other reserve adjustments	$	9		$	15
	GLB
	Net premiums earned	$	32		$	36
	Policy benefits and other reserve adjustments	12			9
	Net realized gains (losses)	(45		)	(50		)
	Loss recognized in Net income	$	(25	)	$	(23	)
	Less: Net cash received	28			33
	Net increase in liability	$	(53	)	$	(56	)

Commitments_contingencies_and_1

Commitments, contingencies, and guarantees (Tables)	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Balance Sheet Locations, Fair Values In An Asset Or (Liability) Position, And Notional Values/Payment Provisions Of Derivative Instruments
								31-Mar-15							31-Dec-14
		Consolidated		Fair Value							Notional		Fair Value					Notional
		Balance Sheet									Value/							Value/
		Location									Payment							Payment
	(in millions of U.S. dollars)			Derivative Asset				Derivative (Liability)			Provision		Derivative Asset		Derivative (Liability)			Provision
	Investment and embedded derivative instruments
	Foreign currency forward contracts	OA / (AP)		$	15			$	(8	)	$	1,160	$	12	$	(7	)	$	1,329
	Cross-currency swaps	OA / (AP)		—				—			95		—		—			95
	Futures contracts on money market instruments	OA / (AP)		1				(1		)	4,355		—		—			2,467
	Options/Futures contracts on notes and bonds	OA / (AP)		5				(16		)	1,276		6		(29		)	1,636
	Convertible securities(1)	FM AFS / ES		298				—			272		291		—			267
	TBAs	FM AFS		31				—			30		—		—			—
				$	350			$	(25	)	$	7,188	$	309	$	(36	)	$	5,794
	Other derivative instruments
	Futures contracts on equities (2)	OA / (AP)		$	—			$	(3	)	$	1,340	$	—	$	(21	)	$	1,384
	Options on equity market indices (2)	OA / (AP)		1				—			250		2		—			250
	Other	OA / (AP)		—				(4		)	10		—		(4		)	10
				$	1			$	(7	)	$	1,600	$	2	$	(25	)	$	1,644
	GLB(3)	(AP) / (FPB)		$	—			$	(716	)	$	748	$	—	$	(663	)	$	675
	(1)	Includes fair value of embedded derivatives.
	(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 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
		Three Months Ended
		31-Mar
	(in millions of U.S. dollars)	2015				2014
	Investment and embedded derivative instruments
	Foreign currency forward contracts	$	25			$	(3	)
	All other futures contracts and options	(29		)		(22		)
	Convertible securities(1)	5				—
	Total investment and embedded derivative instruments	$	1			$	(25	)
	GLB and other derivative instruments
	GLB(2)	$	(45	)		$	(48	)
	Futures contracts on equities(3)	(11		)		(17		)
	Options on equity market indices(3)	(1		)		(2		)
	Other	—				(2		)
	Total GLB and other derivative instruments	$	(57	)		$	(69	)
		$	(56	)		$	(94	)
	(1)	Includes embedded derivatives.
	(2)	Excludes foreign exchange gains (losses) related to GLB.
	(3)	Related to GMDB and GLB blocks of business.

Shareholders_equity_Shareholde

Shareholders' equity Shareholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2015
Shareholders' equity [Abstract]
Dividends Declared [Table Text Block]	The following table presents dividend distributions per Common Share in Swiss francs (CHF) and U.S. dollars (USD):
		Three Months Ended
		31-Mar
		2015					2014
		CHF		USD			CHF			USD
	Dividends – par value reduction	0.62		$	0.65		0.45			$	0.51
	Dividends – distributed from capital contribution reserves	—		—			0.2			0.24
	Total dividend distributions per common share	0.62		$	0.65		0.65			$	0.75
Share Repurchase Program [Table Text Block]	The following table presents repurchases of ACE's Common Shares conducted in a series of open market transactions under the Board authorizations:
	(in millions of U.S. dollars, except share data)	Three Months Ended						April 1, 2015 through April 28, 2015
		March 31
		2015			2014
	Number of shares repurchased	3,027,463			3,487,882			1,351,820
	Dollar value of shares repurchased	$	340		$	332		$	149
	Repurchase authorization remaining at end of period	$	1,160		$	1,612		$	1,011

Segment_information_Tables

Segment information (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Operations By Segment
	For the Three Months Ended March 31, 2015	Insurance – North American P&C			Insurance – North American Agriculture			Insurance –			Global			Life			Corporate			ACE
								Overseas			Reinsurance									Consolidated
	(in millions of U.S. dollars)							General
	Net premiums written	$	1,430		$	88		$	1,794		$	273		$	491		$	—		$	4,076
	Net premiums earned	1,526			64			1,637			226			474			—			3,927
	Losses and loss expenses	1,035			22			814			99			152			—			2,122
	Policy benefits	—			—			—			—			142			—			142
	Policy acquisition costs	161			(4		)	389			54			107			—			707
	Administrative expenses	171			(1		)	256			12			73			43			554
	Underwriting income (loss)	159			47			178			61			—			(43		)	402
	Net investment income	263			6			138			75			66			3			551
	Net realized gains (losses) including OTTI	(6		)	—			(10		)	(11		)	(59		)	(3		)	(89		)
	Interest expense	2			—			1			1			1			63			68
	Other (income) expense:
	(Gains) losses from fair value changes in separate account assets	—			—			—			—			(11		)	—			(11		)
	Other	(7		)	8			17			(5		)	(12		)	5			6
	Income tax expense (benefit)	80			10			52			8			9			(39		)	120
	Net income (loss)	$	341		$	35		$	236		$	121		$	20		$	(72	)	$	681
	For the Three Months Ended March 31, 2014	Insurance – North American P&C			Insurance – North American Agriculture			Insurance –			Global			Life			Corporate			ACE
								Overseas			Reinsurance									Consolidated
	(in millions of U.S. dollars)							General
	Net premiums written	$	1,418		$	194		$	1,771		$	308		$	494		$	—		$	4,185
	Net premiums earned	1,487			103			1,612			284			484			—			3,970
	Losses and loss expenses	940			126			817			126			151			1			2,161
	Policy benefits	—			—			—			—			114			—			114
	Policy acquisition costs	159			5			386			67			111			—			728
	Administrative expenses	161			1			250			14			68			41			535
	Underwriting income (loss)	227			(29		)	159			77			40			(42		)	432
	Net investment income	270			7			132			77			64			3			553
	Net realized gains (losses) including OTTI	(9		)	(2		)	(10		)	(8		)	(76		)	1			(104		)
	Interest expense	3			—			1			1			3			63			71
	Other (income) expense:
	(Gains) losses from fair value changes in separate account assets	—			—			—			—			6			—			6
	Other	(20		)	8			(6		)	(19		)	7			7			(23		)
	Income tax expense (benefit)	83			(7		)	37			10			10			(40		)	93
	Net income (loss)	$	422		$	(25	)	$	249		$	154		$	2		$	(68	)	$	734
Net Premiums Earned For Segment By Product
	(in millions of U.S. dollars)	Property &			Casualty			Life,			ACE
		All Other						Accident &			Consolidated
	For the Three Months Ended March 31, 2015							Health
	Insurance – North American P&C	$	410		$	1,015		$	101		$	1,526
	Insurance – North American Agriculture	64			—			—			64
	Insurance – Overseas General	728			382			527			1,637
	Global Reinsurance	117			109			—			226
	Life	—			—			474			474
		$	1,319		$	1,506		$	1,102		$	3,927
	For the Three Months Ended March 31, 2014
	Insurance – North American P&C	$	405		$	981		$	101		$	1,487
	Insurance – North American Agriculture	103			—			—			103
	Insurance – Overseas General	693			369			550			1,612
	Global Reinsurance	154			130			—			284
	Life	—			—			484			484
		$	1,355		$	1,480		$	1,135		$	3,970

Earnings_per_share_Tables

Earnings per share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule Of Earnings Per Share, Basic And Diluted
		Three Months Ended
		31-Mar
	(in millions of U.S. dollars, except share and per share data)	2015		2014
	Numerator:
	Net income	$	681	$	734
	Denominator:
	Denominator for basic earnings per share:
	Weighted-average shares outstanding	328,212,376		338,869,562
	Denominator for diluted earnings per share:
	Share-based compensation plans	3,480,344		3,171,174
	Weighted-average shares outstanding and assumed conversions	331,692,720		342,040,736
	Basic earnings per share	$	2.08	$	2.16
	Diluted earnings per share	$	2.05	$	2.14
	Potential anti-dilutive share conversions	715,148		657,182

Information_provided_in_connec1

Information provided in connection with outstanding debt of subsidiaries (Tables)	3 Months Ended
	Mar. 31, 2015
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Abstract]
Condensed Consolidating Balance Sheet	Condensed Consolidating Balance Sheet at March 31, 2015
	(in millions of U.S. dollars)	ACE			ACE INA			Other ACE			Consolidating			ACE Limited
		Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		(Parent			(Subsidiary			Subsidiaries
		Guarantor)			Issuer)
	Assets
	Investments	$	31		$	10		$	63,853		$	—		$	63,894
	Cash(1)	2			366			658			(78		)	948
	Insurance and reinsurance balances receivable	—			—			5,746			(720		)	5,026
	Reinsurance recoverable on losses and loss expenses	—			—			20,292			(8,704		)	11,588
	Reinsurance recoverable on policy benefits	—			—			1,171			(956		)	215
	Value of business acquired	—			—			440			—			440
	Goodwill and other intangible assets	—			—			5,516			—			5,516
	Investments in subsidiaries	29,798			18,767			—			(48,565		)	—
	Due from subsidiaries and affiliates, net	233			—			—			(233		)	—
	Other assets	4			291			14,088			(3,612		)	10,771
	Total assets	$	30,068		$	19,434		$	111,764		$	(62,868	)	$	98,398
	Liabilities
	Unpaid losses and loss expenses	$	—		$	—		$	45,518		$	(8,192	)	$	37,326
	Unearned premiums	—			—			9,912			(1,730		)	8,182
	Future policy benefits	—			—			5,700			(956		)	4,744
	Due to subsidiaries and affiliates, net	—			103			130			(233		)	—
	Affiliated notional cash pooling programs(1)	78			—			—			(78		)	—
	Short-term debt	—			1,150			1,402			—			2,552
	Long-term debt	—			4,145			12			—			4,157
	Trust preferred securities	—			309			—			—			309
	Other liabilities	288			1,434			12,818			(3,114		)	11,426
	Total liabilities	366			7,141			75,492			(14,303		)	68,696
	Total shareholders’ equity	29,702			12,293			36,272			(48,565		)	29,702
	Total liabilities and shareholders’ equity	$	30,068		$	19,434		$	111,764		$	(62,868	)	$	98,398
	(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
	Condensed Consolidating Balance Sheet at December 31, 2014
	(in millions of U.S. dollars)	ACE			ACE INA			Other ACE			Consolidating			ACE Limited
		Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Consolidated
		(Parent			(Subsidiary			Subsidiaries
		Guarantor)			Issuer)
	Assets
	Investments	$	30		$	225		$	62,649		$	—		$	62,904
	Cash(1)	—			1			1,209			(555		)	655
	Insurance and reinsurance balances receivable	—			—			6,178			(752		)	5,426
	Reinsurance recoverable on losses and loss expenses	—			—			20,992			(9,000		)	11,992
	Reinsurance recoverable on policy benefits	—			—			1,194			(977		)	217
	Value of business acquired	—			—			466			—			466
	Goodwill and other intangible assets	—			—			5,724			—			5,724
	Investments in subsidiaries	29,497			18,762			—			(48,259		)	—
	Due from subsidiaries and affiliates, net	583			—			—			(583		)	—
	Other assets	4			295			14,196			(3,631		)	10,864
	Total assets	$	30,114		$	19,283		$	112,608		$	(63,757	)	$	98,248
	Liabilities
	Unpaid losses and loss expenses	$	—		$	—		$	46,770		$	(8,455	)	$	38,315
	Unearned premiums	—			—			9,958			(1,736		)	8,222
	Future policy benefits	—			—			5,731			(977		)	4,754
	Due to subsidiaries and affiliates, net	—			422			161			(583		)	—
	Affiliated notional cash pooling programs(1)	246			309			—			(555		)	—
	Short-term debt	—			1,150			1,402			—			2,552
	Long-term debt	—			3,345			12			—			3,357
	Trust preferred securities	—			309			—			—			309
	Other liabilities	281			1,404			12,659			(3,192		)	11,152
	Total liabilities	527			6,939			76,693			(15,498		)	68,661
	Total shareholders’ equity	29,587			12,344			35,915			(48,259		)	29,587
	Total liabilities and shareholders’ equity	$	30,114		$	19,283		$	112,608		$	(63,757	)	$	98,248
	(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2014, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condensed Consolidating Statement Of Operations and Comprehensive Income	Condensed Consolidating Statements of Operations and Comprehensive Income
	For the Three Months Ended March 31, 2015	ACE			ACE INA			Other ACE			Consolidating			ACE
		Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Limited
		(Parent			(Subsidiary			Subsidiaries						Consolidated
	(in millions of U.S. dollars)	Guarantor)			Issuer)
	Net premiums written	$	—		$	—		$	4,076		$	—		$	4,076
	Net premiums earned	—			—			3,927			—			3,927
	Net investment income	1			1			549			—			551
	Equity in earnings of subsidiaries	648			204			—			(852		)	—
	Net realized gains (losses) including OTTI	—			—			(89		)	—			(89		)
	Losses and loss expenses	—			—			2,122			—			2,122
	Policy benefits	—			—			142			—			142
	Policy acquisition costs and administrative expenses	14			6			1,241			—			1,261
	Interest (income) expense	(8		)	69			7			—			68
	Other (income) expense	(41		)	(3		)	39			—			(5		)
	Income tax expense (benefit)	3			(26		)	143			—			120
	Net income	$	681		$	159		$	693		$	(852	)	$	681
	Comprehensive income	$	642		$	24		$	654		$	(678	)	$	642
	Condensed Consolidating Statements of Operations and Comprehensive Income
	For the Three Months Ended March 31, 2014	ACE			ACE INA			Other ACE			Consolidating			ACE
		Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Limited
		(Parent			(Subsidiary			Subsidiaries						Consolidated
	(in millions of U.S. dollars)	Guarantor)			Issuer)
	Net premiums written	$	—		$	—		$	4,185		$	—		$	4,185
	Net premiums earned	—			—			3,970			—			3,970
	Net investment income	—			—			553			—			553
	Equity in earnings of subsidiaries	702			180			—			(882		)	—
	Net realized gains (losses) including OTTI	—			(1		)	(103		)	—			(104		)
	Losses and loss expenses	—			—			2,161			—			2,161
	Policy benefits	—			—			114			—			114
	Policy acquisition costs and administrative expenses	17			6			1,240			—			1,263
	Interest (income) expense	(10		)	71			10			—			71
	Other (income) expense	(42		)	14			11			—			(17		)
	Income tax expense (benefit)	3			(30		)	120			—			93
	Net income	$	734		$	118		$	764		$	(882	)	$	734
	Comprehensive income	$	1,108		$	266		$	1,138		$	(1,404	)	$	1,108
Condensed Consolidating Statement of Cash Flows	Condensed Consolidating Statement of Cash Flows
	Three Months Ended March 31, 2015	ACE			ACE INA			Other ACE			Consolidating			ACE
		Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Limited
		(Parent			(Subsidiary			Subsidiaries						Consolidated
	(in millions of U.S. dollars)	Guarantor)			Issuer)
	Net cash flows from operating activities	$	48		$	4		$	1,023		$	—		$	1,075
	Cash flows from investing activities
	Purchases of fixed maturities available for sale	—			—			(4,336		)	—			(4,336		)
	Purchases of fixed maturities held to maturity	—			—			(21		)	—			(21		)
	Purchases of equity securities	—			—			(39		)	—			(39		)
	Sales of fixed maturities available for sale	—			—			2,002			—			2,002
	Sales of equity securities	—			—			28			—			28
	Maturities and redemptions of fixed maturities available for sale	—			—			1,481			—			1,481
	Maturities and redemptions of fixed maturities held to maturity	—			—			324			—			324
	Net change in short-term investments	—			216			(471		)	—			(255		)
	Net derivative instruments settlements	—			—			(51		)	—			(51		)
	Other	—			—			(153		)	—			(153		)
	Net cash flows from (used for) investing activities	—			216			(1,236		)	—			(1,020		)
	Cash flows from financing activities
	Dividends paid on Common Shares	(214		)	—			—			—			(214		)
	Common Shares repurchased	—			—			(347		)	—			(347		)
	Proceeds from issuance of long-term debt	—			800			—			—			800
	Proceeds from issuance of short-term debt	—			—			477			—			477
	Repayment of short-term debt	—			—			(477		)	—			(477		)
	Proceeds from share-based compensation plans, including windfall tax benefits	—			—			39			—			39
	Advances (to) from affiliates	336			(340		)	4			—			—
	Net payments to affiliated notional cash pooling programs(1)	(168		)	(309		)	—			477			—
	Policyholder contract deposits	—			—			101			—			101
	Policyholder contract withdrawals	—			—			(40		)	—			(40		)
	Other	—			(6		)	—			—			(6		)
	Net cash flows (used for) from financing activities	(46		)	145			(243		)	477			333
	Effect of foreign currency rate changes on cash and cash equivalents	—			—			(95		)	—			(95		)
	Net increase (decrease) in cash	2			365			(551		)	477			293
	Cash – beginning of period(1)	—			1			1,209			(555		)	655
	Cash – end of period(1)	$	2		$	366		$	658		$	(78	)	$	948
	(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015 and December 31, 2014, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
	Condensed Consolidating Statement of Cash Flows
	Three Months Ended March 31, 2014	ACE			ACE INA			Other ACE			Consolidating			ACE
		Limited			Holdings Inc.			Limited			Adjustments and Eliminations			Limited
		(Parent			(Subsidiary			Subsidiaries						Consolidated
	(in millions of U.S. dollars)	Guarantor)			Issuer)
	Net cash flows from (used for) operating activities	$	57		$	(13	)	$	1,206		$	—		$	1,250
	Cash flows from investing activities
	Purchases of fixed maturities available for sale	—			—			(3,522		)	—			(3,522		)
	Purchases of fixed maturities held to maturity	—			—			(30		)	—			(30		)
	Purchases of equity securities	—			—			(37		)	—			(37		)
	Sales of fixed maturities available for sale	—			—			2,208			—			2,208
	Sales of equity securities	—			—			27			—			27
	Maturities and redemptions of fixed maturities available for sale	—			—			1,550			—			1,550
	Maturities and redemptions of fixed maturities held to maturity	—			—			212			—			212
	Net change in short-term investments	—			(8		)	(757		)	—			(765		)
	Net derivative instruments settlements	—			(9		)	(87		)	—			(96		)
	Other	—			(3		)	(47		)	—			(50		)
	Net cash flows used for investing activities	—			(20		)	(483		)	—			(503		)
	Cash flows from financing activities
	Dividends paid on Common Shares	(214		)	—			—			—			(214		)
	Common Shares repurchased	—			—			(335		)	—			(335		)
	Proceeds from issuance of short-term debt	—			—			426			—			426
	Repayment of short-term debt	—			—			(426		)	—			(426		)
	Proceeds from share-based compensation plans, including windfall tax benefits	—			—			40			—			40
	Advances (to) from affiliates	367			(367		)	—			—			—
	Net proceeds from (payments to) affiliated notional cash pooling programs(1)	(185		)	385			—			(200		)	—
	Policyholder contract deposits	—			—			51			—			51
	Policyholder contract withdrawals	—			—			(14		)	—			(14		)
Net cash flows (used for) from financing activities	(32		)	18			(258		)	(200		)	(472		)
Effect of foreign currency rate changes on cash and cash equivalents	—			—			(7		)	—			(7		)
Net increase (decrease) in cash	25			(15		)	458			(200		)	268
Cash – beginning of period(1)	—			16			748			(185		)	579
Cash – end of period(1)	$	25		$	1		$	1,206		$	(385	)	$	847
(1)	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2014 and December 31, 2013, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

Acquisitions_Detail

Acquisitions (Detail) (USD $)	0 Months Ended
In Millions, unless otherwise specified	Jun. 17, 2014	Apr. 28, 2014	Oct. 31, 2014	Apr. 01, 2015
The Siam Commercial Samaggi Insurance PCL [Member]
Business Acquisition [Line Items]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage	32.17%	60.86%
Business Acquisition, Purchase Price Allocation, Goodwill Amount		$46
Business Acquisition, Purchase Price Allocation, Intangible Assets Other than Goodwill		80
Business Combination Total Ownership Percentage	93.03%
Business Combination, Consideration Transferred	176
Large Corporate P&C Business Of Itau Seguros [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Goodwill Amount			449
Business Acquisition, Purchase Price Allocation, Intangible Assets Other than Goodwill			60
Business Acquisition, Cost of Acquired Entity, Expected Cash Consideration			610
Fireman's Fund high net worth personal lines [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Expected Cash Consideration				$365

Investments_Narrative_Detail

Investments (Narrative) (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Mar. 27, 2015	Apr. 30, 2015	Apr. 14, 2015
	Security
Investment [Line Items]
Total number of fixed maturities	33,429
Largest single unrealized loss in the fixed maturities	$3,000,000
Number of equity securities in an unrealized loss position	78
Total number of equity securities	306
Largest single unrealized loss in the equity securities	1,000,000
Restricted assets in fixed maturities and short-term investments	16,500,000,000		16,300,000,000
Restricted assets in cash	102,000,000		117,000,000
Moodys Historical Mean Recovery Rate	42.00%
Company Assumed Recovery Rate	32.00%
Net unrealized depreciation included in AOCI	2,000,000		3,000,000
Investments in partially-owned insurance companies	590,000,000		504,000,000
Net unrealized appreciation (depreciation) included in OCI	-4,000,000	-4,000,000
Number of fixed maturities in an unrealized loss position	3,313
Credit losses recognized in net income for mortgage-backed securities	0	0
Credit losses recognized in net income for corporate securities	4,000,000	4,000,000
Percentage of mortgage-backed securities represented by investments in US government agency bonds	82.00%		83.00%
ABR Reinsurance Capital Holdings Ltd. [Member]
Investment [Line Items]
Investments in partially-owned insurance companies				70,000,000
Warrants & Rights Outstanding				0.50%
Subsequent Event [Member]
Investment [Line Items]
Fair value of securities transferred from AFS to HTM					1,800,000,000
Subsequent Event [Member] | ABR Reinsurance Capital Holdings Ltd. [Member]
Investment [Line Items]
Equity Method Investment, Ownership Percentage						11.30%
Investments in partially-owned insurance companies						$20,000,000

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 $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Investment [Line Items]
Document Period End Date	31-Mar-15
Held to maturity, Amortized Cost	$6,982	$7,331
Held to maturity, Gross Unrealized Appreciation	327	266
Held to maturity, Gross Unrealized Depreciation	-2	-8
Held to maturity, Fair Value	7,307	7,589
Available for sale, Amortized Cost	48,384	47,826
AvailableforsaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments	2,215	1,871
Available for sale, Gross Unrealized Depreciation	-189	-302
Available for sale, Fair Value	50,410	49,395
Available for sale, OTTI recognized in AOCI	-7	-8
U.S. Treasury And Agency [Member]
Investment [Line Items]
Held to maturity, Amortized Cost	756	832
Held to maturity, Gross Unrealized Appreciation	24	20
Held to maturity, Gross Unrealized Depreciation	0	-2
Held to maturity, Fair Value	780	850
Held to maturity, OTTI recognized in AOCI	0	0
Available for sale, Amortized Cost	2,793	2,741
AvailableforsaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments	98	87
Available for sale, Gross Unrealized Depreciation	-2	-8
Available for sale, Fair Value	2,889	2,820
Available for sale, OTTI recognized in AOCI	0	0
Foreign [Member]
Investment [Line Items]
Held to maturity, Amortized Cost	816	916
Held to maturity, Gross Unrealized Appreciation	57	47
Held to maturity, Gross Unrealized Depreciation	0	0
Held to maturity, Fair Value	873	963
Held to maturity, OTTI recognized in AOCI	0	0
Available for sale, Amortized Cost	14,262	14,703
AvailableforsaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments	761	629
Available for sale, Gross Unrealized Depreciation	-76	-90
Available for sale, Fair Value	14,947	15,242
Available for sale, OTTI recognized in AOCI	0	0
Corporate Securities [Member]
Investment [Line Items]
Held to maturity, Amortized Cost	2,249	2,323
Held to maturity, Gross Unrealized Appreciation	122	102
Held to maturity, Gross Unrealized Depreciation	0	-2
Held to maturity, Fair Value	2,371	2,423
Held to maturity, OTTI recognized in AOCI	0	0
Available for sale, Amortized Cost	17,259	16,897
AvailableforsaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments	834	704
Available for sale, Gross Unrealized Depreciation	-94	-170
Available for sale, Fair Value	17,999	17,431
Available for sale, OTTI recognized in AOCI	-6	-7
Mortgage Backed-Securities [Member]
Investment [Line Items]
Held to maturity, Amortized Cost	1,907	1,983
Held to maturity, Gross Unrealized Appreciation	77	57
Held to maturity, Gross Unrealized Depreciation	-1	-1
Held to maturity, Fair Value	1,983	2,039
Held to maturity, OTTI recognized in AOCI	0	0
Available for sale, Amortized Cost	10,459	10,011
AvailableforsaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments	362	304
Available for sale, Gross Unrealized Depreciation	-13	-29
Available for sale, Fair Value	10,808	10,286
Available for sale, OTTI recognized in AOCI	-1	-1
States, Municipalities, And Political Subdivisions [Member]
Investment [Line Items]
Held to maturity, Amortized Cost	1,254	1,277
Held to maturity, Gross Unrealized Appreciation	47	40
Held to maturity, Gross Unrealized Depreciation	-1	-3
Held to maturity, Fair Value	1,300	1,314
Held to maturity, OTTI recognized in AOCI	0	0
Available for sale, Amortized Cost	3,611	3,474
AvailableforsaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments	160	147
Available for sale, Gross Unrealized Depreciation	-4	-5
Available for sale, Fair Value	3,767	3,616
Available for sale, OTTI recognized in AOCI	$0	$0

Investments_Schedule_Of_Fixed_

Investments (Schedule Of Fixed Maturities By Contractual Maturity) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]
Available for sale, Due in 1 year or less, Amortized Cost	$2,021	$2,187
Available for sale, Due after 1 year through 5 years, Amortized Cost	16,209	15,444
Available for sale, Due after 5 years though 10 years, Amortized Cost	15,047	15,663
Available for sale, Due after 10 years, Amortized Cost	4,648	4,521
Available for sale, Subtotal, Amortized Cost	37,925	37,815
Available for sale, Mortgage-backed securities, Amortized Cost	10,459	10,011
Available for sale, Amortized Cost	48,384	47,826
Available for sale, Fair Value	50,410	49,395
Held to maturity, Due in 1 year or less, Amortized Cost	318	353
Held to maturity, Due after 1 year through 5 years, Amortized Cost	2,594	2,603
Held to maturity, Due after 5 years through 10 years, Amortized Cost	1,214	1,439
Held to maturity, Due after 10 years, Amortized Cost	949	953
Held to maturity, Subtotal, Amortized Cost	5,075	5,348
Held to maturity, Mortgage backed securities, Amortized Cost	1,907	1,983
Available for sale, Due in 1 year or less, Fair Value	2,042	2,206
Available for sale, Due after 1 year through 5 years, Fair Value	16,735	15,857
Available for sale, Due after 5 years through 10 years, Fair Value	15,649	16,089
Available for sale, Due after 10 years, Fair Value	5,176	4,957
Available for sale, Subtotal, Fair Value	39,602	39,109
Available for sale, Mortgage backed securities, Fair Value	10,808	10,286
Held to maturity, Due in 1 year or less, Fair Value	321	355
Held to maturity, Due after 1 year through 5, Fair Value	2,706	2,693
Held to maturity, Due after 5 years through 10 years, Fair Value	1,270	1,489
Held to maturity, Due after 10 years, Fair Value	1,027	1,013
Held to maturity, Subtotal, Fair Value	5,324	5,550
Held to maturity, Mortgage backed securities, Fair Value	1,983	2,039
Held-to-maturity Securities	6,982	7,331
Held to maturity, Fair Value	$7,307	$7,589

Investments_Schedule_Of_Cost_A

Investments (Schedule Of Cost And Fair Value Of Equity Securities) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]
Cost	$447	$440
Gross unrealized appreciation	99	83
Gross unrealized depreciation	-10	-13
Fair value	$536	$510

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
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]
OTTI on fixed maturities, gross	($13)	($6)
OTTI on fixed maturities recognized in OCI (pre-tax)	0	1
OTTI on fixed maturities, net	-13	-5
Fixed maturities, Gross realized gains excluding OTTI	44	36
Fixed maturities, Gross realized losses excluding OTTI	-35	-20
Total fixed maturities	-4	11
OTTI on equity securities	0	-6
Equity securities, Gross realized gains excluding OTTI	3	2
Equity securities, Gross realized losses excluding OTTI	-2	-1
Total equity securities	1	-5
OTTI on other investments	0	0
Foreign exchange losses	-31	-9
Investment and embedded derivative instruments	1	-25
Fair value adjustments on insurance derivative	-45	-48
S&P put options and futures	-12	-19
Other derivative instruments	0	-2
Other	1	-7
Total net realized gains (losses) (includes $(3) and $6 reclassified from AOCI)	($89)	($104)

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 $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
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 [Roll Forward]
Balance of credit losses related to securities still held – beginning of period	$28	$37
Additions where no OTTI was previously recorded	3	2
Additions where an OTTI was previously recorded	1	2
Reductions for securities sold during the period	-10	-6
Balance of credit losses related to securities still held – end of period	$22	$35

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 $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Investment [Line Items]
Document Period End Date	31-Mar-15
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	$6,253	$8,559
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-169	-244
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	1,607	3,932
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-38	-79
Investment securities, Unrealized loss position, Total Fair Value	7,860	12,491
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-207	-323
US Treasury and Government [Member]
Investment [Line Items]
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	443	350
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-1	-1
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	141	666
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-1	-9
Investment securities, Unrealized loss position, Total Fair Value	584	1,016
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-2	-10
Foreign Government Debt Securities [Member]
Investment [Line Items]
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	1,747	2,262
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-64	-75
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	317	375
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-12	-15
Investment securities, Unrealized loss position, Total Fair Value	2,064	2,637
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-76	-90
Corporate Securities [Member]
Investment [Line Items]
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	2,140	4,684
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-79	-150
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	500	738
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-15	-22
Investment securities, Unrealized loss position, Total Fair Value	2,640	5,422
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-94	-172
Collateralized Mortgage Backed Securities [Member]
Investment [Line Items]
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	1,301	704
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-6	-2
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	560	1,663
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-8	-28
Investment securities, Unrealized loss position, Total Fair Value	1,861	2,367
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-14	-30
US States and Political Subdivisions Debt Securities [Member]
Investment [Line Items]
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	462	458
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-3	-3
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	89	490
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-2	-5
Investment securities, Unrealized loss position, Total Fair Value	551	948
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-5	-8
Fixed Maturities [Member]
Investment [Line Items]
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	6,093	8,458
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-153	-231
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	1,607	3,932
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	-38	-79
Investment securities, Unrealized loss position, Total Fair Value	7,700	12,390
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-191	-310
Equity Securities [Member]
Investment [Line Items]
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	68	101
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-10	-13
Investment securities, Unrealized loss position, Over 12 Months, Fair Value	0	0
Investment securities, Unrealized loss position, Over 12 Months, Gross Unrealized Loss	0	0
Investment securities, Unrealized loss position, Total Fair Value	68	101
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	-10	-13
Other Long-term Investments [Member]
Investment [Line Items]
Investment securities, Unrealized loss position, 0-12 Months, Fair Value	92
Investment securities, Unrealized loss position, 0-12 Months, Gross Unrealized Loss	-6
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	92
Investment securities, Unrealized loss position, Total Gross Unrealized Loss	($6)

Investments_Schedule_Of_Compon

Investments (Schedule Of Components Of Restricted Assets) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]
Trust funds	$11,132	$10,838
Deposits with non-U.S. regulatory authorities	2,296	2,305
Assets pledged under repurchase agreements	1,459	1,431
Deposits with U.S. regulatory authorities	1,336	1,345
Other pledged assets	446	457
Total restricted assets	$16,669	$16,376

Fair_Value_Measurements_Narrat

Fair Value Measurements (Narrative) (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Fair Value Measurements Of Financial Instruments [Line Items]
Guaranteed Living Benefits, Net Income Impact From Model Refinement	$400	$3,000
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

Fair_Value_Measurements_Financ

Fair Value Measurements (Financial Instruments Measured At Fair Value On Recurring Basis) (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	$50,410		$49,395
Equity securities, at fair value	536		510
Short-term investments	2,536		2,322
Other investments	3,430		3,346
Securities lending collateral	1,033		1,330
Investment derivative instruments, assets	21		18
Other derivative instruments, assets	1		2
Separate account assets	1,574		1,490
Total assets measured at fair value	59,541		58,413
Investment derivative instruments, liabilities	25		36
Other derivative instruments, liability	7		25
GLB	451	[1]	406	[1]
Total liabilities measured at fair value	483		467
Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	1,747		1,680
Equity securities, at fair value	518		492
Short-term investments	1,469		1,183
Other investments	364		370
Securities lending collateral	0		0
Investment derivative instruments, assets	21		18
Other derivative instruments, assets	0		0
Separate account assets	1,488		1,400
Total assets measured at fair value	5,607		5,143
Investment derivative instruments, liabilities	25		36
Other derivative instruments, liability	3		21
GLB	0	[1]	0	[1]
Total liabilities measured at fair value	28		57
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	48,441		47,491
Equity securities, at fair value	16		16
Short-term investments	1,067		1,139
Other investments	277		257
Securities lending collateral	1,033		1,330
Investment derivative instruments, assets	0		0
Other derivative instruments, assets	1		2
Separate account assets	86		90
Total assets measured at fair value	50,921		50,325
Investment derivative instruments, liabilities	0		0
Other derivative instruments, liability	0		0
GLB	0	[1]	0	[1]
Total liabilities measured at fair value	0		0
Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	222		224
Equity securities, at fair value	2		2
Short-term investments	0		0
Other investments	2,789		2,719
Securities lending collateral	0		0
Investment derivative instruments, assets	0		0
Other derivative instruments, assets	0		0
Separate account assets	0		0
Total assets measured at fair value	3,013		2,945
Investment derivative instruments, liabilities	0		0
Other derivative instruments, liability	4		4
GLB	451	[1]	406	[1]
Total liabilities measured at fair value	455		410
U.S. Treasury And Agency [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	2,889		2,820
U.S. Treasury And Agency [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	1,747		1,680
U.S. Treasury And Agency [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	1,142		1,140
U.S. Treasury And Agency [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	0		0
Foreign [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	14,947		15,242
Foreign [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	0		0
Foreign [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	14,925		15,220
Foreign [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	22		22
Corporate Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	17,999		17,431
Corporate Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	0		0
Corporate Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	17,832		17,244
Corporate Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	167		187
Mortgage Backed-Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	10,808		10,286
Mortgage Backed-Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	0		0
Mortgage Backed-Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	10,775		10,271
Mortgage Backed-Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	33		15
States, Municipalities, And Political Subdivisions [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	3,767		3,616
States, Municipalities, And Political Subdivisions [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	0		0
States, Municipalities, And Political Subdivisions [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	3,767		3,616
States, Municipalities, And Political Subdivisions [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fixed maturities available for sale at fair value	$0		$0
[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 for additional information.

Fair_Value_Measurements_Fair_V

Fair Value Measurements (Fair Value And Maximum Future Funding Commitments Related To Investments) (Detail) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Minimum [Member]
Fair Value And Maximum Future Funding Commitments Related To Investments [Line Items]
Liquidation period for financial alternative investments (in years)	5 years	5 years
Liquidation period for real assets alternative investments (in years)	3 years	3 years
Liquidation period for distressed alternative investments (in years)	5 years	5 years
Liquidation period for private credit alternative investments (in years)	3 years	3 years
Liquidation period for traditional alternative investments (in years)	3 years	3 years
Liquidation period for vintage alternative investments (in years)	1 year	1 year
Maximum [Member]
Fair Value And Maximum Future Funding Commitments Related To Investments [Line Items]
Liquidation period for financial alternative investments (in years)	9 years	9 years
Liquidation period for real assets alternative investments (in years)	7 years	7 years
Liquidation period for distressed alternative investments (in years)	9 years	9 years
Liquidation period for private credit alternative investments (in years)	7 years	7 years
Liquidation period for traditional alternative investments (in years)	9 years	9 years
Liquidation period for vintage alternative investments (in years)	2 years	2 years
Fair Value [Member]
Fair Value And Maximum Future Funding Commitments Related To Investments [Line Items]
Financial	298	282
Real assets	478	464
Distressed	251	232
Private credit	303	299
Traditional	910	895
Vintage	9	11
Investment funds	383	378
Total of alternative investments	2,632	2,561
Maximum Future Funding Commitments [Member]
Fair Value And Maximum Future Funding Commitments Related To Investments [Line Items]
Financial	130	145
Real assets	193	214
Distressed	249	175
Private credit	181	190
Traditional	239	285
Vintage	0	1
Investment funds	0	0
Total of alternative investments	992	1,010

Fair_Value_Measurements_Schedu

Fair Value Measurements (Schedule Of Significant Unobservable Inputs Used In Level 3 Liability Valuations) (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014		Dec. 31, 2013
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Valuation Technique	Actuarial model	[1]
Minimum [Member]
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 [Member]
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 Living Benefit [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	$451	[2]	$243	[2]	$406	[2]	$193	[2]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	45	[2]	50	[2]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	0
Fair Value	451	[1]			406	[1]
Short-term Investments [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value			0				7
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases			$0
[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 for additional information.

Fair_Value_Measurements_Financ1

Fair Value Measurements (Financial Instruments Measured At Fair Value Using Significant Unobservable Inputs) (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014		Dec. 31, 2013
Equity Securities [Member]
Schedule Of Fair Value Measurements [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	$0		$0
Balance- Beginning of Period, Assets	2		4
Transfers out of Level 3, Assets	0		-2
Change in Net Unrealized Gains (Losses) included in OCI, Assets	0		1
Net Realized Gains/Losses, Assets	0		0
Purchases, Assets	0		1
Sales, Assets	0		-2
Settlements, Assets	0		0
Balance-End of Period, Assets	2		2
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets			0
Short-term Investments [Member]
Schedule Of Fair Value Measurements [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3			0
Balance- Beginning of Period, Assets			7
Transfers out of Level 3, Assets			-7
Change in Net Unrealized Gains (Losses) included in OCI, Assets			0
Net Realized Gains/Losses, Assets			0
Purchases, Assets			0
Sales, Assets			0
Settlements, Assets			0
Balance-End of Period, Assets			0
Other Long-term Investments [Member]
Schedule Of Fair Value Measurements [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0		0
Balance- Beginning of Period, Assets	2,719		2,440
Transfers out of Level 3, Assets	0		0
Change in Net Unrealized Gains (Losses) included in OCI, Assets	-20		41
Net Realized Gains/Losses, Assets	0		0
Purchases, Assets	147		200
Sales, Assets	0		-1
Settlements, Assets	-57		-69
Balance-End of Period, Assets	2,789		2,611
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	0		0
Other Derivative Instruments Fair Value [Member]
Schedule Of Fair Value Measurements [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0
Balance- Beginning of Period, Assets	4
Transfers out of Level 3, Assets	0
Change in Net Unrealized Gains (Losses) included in OCI, Assets	0
Sales, Assets	0
Balance-End of Period, Assets	4
Available-for-sale Securities [Member] | Foreign [Member]
Schedule Of Fair Value Measurements [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0		0
Balance- Beginning of Period, Assets	22		44
Transfers out of Level 3, Assets	0		-18
Change in Net Unrealized Gains (Losses) included in OCI, Assets	0		-1
Net Realized Gains/Losses, Assets	0		0
Purchases, Assets	1		2
Sales, Assets	-1		-1
Settlements, Assets	0		0
Balance-End of Period, Assets	22		26
Available-for-sale Securities [Member] | Corporate Debt Securities [Member]
Schedule Of Fair Value Measurements [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	1		4
Balance- Beginning of Period, Assets	187		166
Transfers out of Level 3, Assets	0		-22
Change in Net Unrealized Gains (Losses) included in OCI, Assets	3		0
Net Realized Gains/Losses, Assets	-3		0
Purchases, Assets	8		15
Sales, Assets	-3		-6
Settlements, Assets	-26		-6
Balance-End of Period, Assets	167		151
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Assets	-2
Available-for-sale Securities [Member] | Mortgage Backed-Securities [Member]
Schedule Of Fair Value Measurements [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0		0
Balance- Beginning of Period, Assets	15		8
Transfers out of Level 3, Assets	0		0
Change in Net Unrealized Gains (Losses) included in OCI, Assets	0		0
Net Realized Gains/Losses, Assets	0		0
Purchases, Assets	18		0
Sales, Assets	0		0
Settlements, Assets	0		0
Balance-End of Period, Assets	33		8
Guaranteed Living Benefit [Member]
Schedule Of Fair Value Measurements [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	451	[1]	243	[1]	406	[1]	193	[1]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0
Transfers out of Level 3, Assets	0
Change in Net Unrealized Gains (Losses) included in OCI, Assets	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	45	[1]	50	[1]
Purchases, Assets	0
Sales, Assets	0
Settlements, Assets	0
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date, Liabilities	45		50	[1]
Reported liabilities	$716		$483		$663		$427
[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 for additional information.

Fair_Value_Measurements_Carryi

Fair Value Measurements (Carrying Values And Fair Values Of Financial Instruments Not Measured At Fair Value) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	$6,982	$7,331
Investments in partially-owned insurance companies	590	504
Total assets	98,398	98,248
Short-term debt	2,552	2,552
Long-term debt	4,157	3,357
Trust preferred securities	309	309
Total liabilities	68,696	68,661
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	6,982	7,331
Investments in partially-owned insurance companies	590	504
Total assets	7,572	7,835
Short-term debt	2,552	2,552
Long-term debt	4,157	3,357
Trust preferred securities	309	309
Total liabilities	7,018	6,218
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	7,307	7,589
Investments in partially-owned insurance companies	590	504
Total assets	7,897	8,093
Short-term debt	2,563	2,571
Long-term debt	4,575	3,690
Trust preferred securities	465	462
Total liabilities	7,603	6,723
Fair Value, Inputs, Level 1 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	590	659
Investments in partially-owned insurance companies	0	0
Total assets	590	659
Short-term debt	0	0
Long-term debt	0	0
Trust preferred securities	0	0
Total liabilities	0	0
Fair Value, Inputs, Level 2 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	6,703	6,915
Investments in partially-owned insurance companies	0	0
Total assets	6,703	6,915
Short-term debt	2,563	2,571
Long-term debt	4,575	3,690
Trust preferred securities	465	462
Total liabilities	7,603	6,723
Fair Value, Inputs, Level 3 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	14	15
Investments in partially-owned insurance companies	590	504
Total assets	604	519
Short-term debt	0	0
Long-term debt	0	0
Trust preferred securities	0	0
Total liabilities	0	0
U.S. Treasury And Agency [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	756	832
U.S. Treasury And Agency [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	780	850
U.S. Treasury And Agency [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	590	659
U.S. Treasury And Agency [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	190	191
U.S. Treasury And Agency [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	0	0
Foreign [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	816	916
Foreign [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	873	963
Foreign [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	0	0
Foreign [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	873	963
Foreign [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	0	0
Corporate Debt Securities [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	2,249	2,323
Corporate Debt Securities [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	2,371	2,423
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	0	0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	2,357	2,408
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	14	15
Collateralized Mortgage Backed Securities [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	1,907	1,983
Collateralized Mortgage Backed Securities [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	1,983	2,039
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	0	0
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	1,983	2,039
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	0	0
US States and Political Subdivisions Debt Securities [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	1,254	1,277
US States and Political Subdivisions Debt Securities [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	1,300	1,314
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	1,300	1,314
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturities held to maturity, at amortized cost (fair value – $7,307 and $7,589)	$0	$0

Recovered_Sheet1

Assumed Life Reinsurance Programs Involving Minimum Benefit Guarantees Under Annuity Contracts (Schedule Of Guaranteed Minimum Benefits Income And Expense) (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Guaranteed Minimum Benefits [Line Items]
Document Fiscal Year Focus	2015
Net premiums earned	$3,927	$3,970
Policy benefits and other reserve adjustments	142	114
Net realized gains (losses)	-89	-104
Guaranteed Minimum Death Benefit [Member]
Guaranteed Minimum Benefits [Line Items]
Net premiums earned	16	19
Policy benefits and other reserve adjustments	9	15
Guaranteed Living Benefit [Member]
Guaranteed Minimum Benefits [Line Items]
Net premiums earned	32	36
Policy benefits and other reserve adjustments	12	9
Net realized gains (losses)	-45	-50
Loss recognized in Net income	-25	-23
Less: Net cash received	28	33
Net increase in liability	($53)	($56)

Recovered_Sheet2

Assumed Life Reinsurance Programs Involving Minimum Benefit Guarantees Under Annuity Contracts (Narrative) (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Guaranteed Minimum Benefits [Line Items]
Document Fiscal Year Focus	2015
Guaranteed Minimum Death Benefit [Member]
Guaranteed Minimum Benefits [Line Items]
Reported liabilities	112	$111
Guaranteed Living Benefit [Member]
Guaranteed Minimum Benefits [Line Items]
Reported liabilities	716	663	483	427
Fair value derivative adjustment in liability	451	$406

Debt_Details

Debt (Details) (Senior Notes [Member], ACE INA Senior Notes Due March 2025 [Member], USD $)	Mar. 01, 2015
In Millions, unless otherwise specified
Senior Notes [Member] | ACE INA Senior Notes Due March 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$800
Debt Instrument, Interest Rate, Stated Percentage	3.15%
Make Whole Premium Additional Percent	0.15%

Recovered_Sheet3

Commitments, Contingencies, And Guarantees (Balance Sheet Locations, Fair Values In Asset Or (Liability) Position, And Notional Values/Payment Provisions Of Derivative Instruments) (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Foreign Exchange Future [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	$1,160		$1,329
Cross Currency Swap [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	95		95
Futures Contracts On Money Market Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	4,355		2,467
Futures contracts on notes and bonds [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	1,276		1,636
Convertibles and Bonds with Warrants Attached [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	272	[1]	267	[1]
TBAs [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	30
Investment And Embedded Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	350		309
Notional Value/Payment Provision	7,188		5,794
Single-Stock Future [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	1,340	[2]	1,384	[2]
Options On Equity Market Indices [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	250	[2]	250	[2]
Other Derivatives [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	10		10
Other Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	1,600		1,644
Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	748	[3]	675	[3]
Other Assets [Member] | Foreign Exchange Future [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	15		12
Other Assets [Member] | Futures Contracts On Money Market Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	1		0
Other Assets [Member] | Futures contracts on notes and bonds [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	5		6
Other Assets [Member] | Single-Stock Future [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	0	[2]	0	[2]
Other Assets [Member] | Options On Equity Market Indices [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	1	[2]	2	[2]
Other Assets [Member] | Other Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	0		0
Other Assets [Member] | Other Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	1		2
Other Assets [Member] | Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	0	[3]	0	[3]
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Foreign Exchange Future [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	-8		-7
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Futures Contracts On Money Market Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	-1		0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Futures contracts on notes and bonds [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	-16		-29
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Convertibles and Bonds with Warrants Attached [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	0	[1]	0	[1]
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Investment And Embedded Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	-25		-36
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Single-Stock Future [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	-3	[2]	-21	[2]
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Options On Equity Market Indices [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	0	[2]	0	[2]
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Other Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	-4		-4
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Other Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	-7		-25
Fixed Maturities Available For Sale [Member] | Convertibles and Bonds with Warrants Attached [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	298	[1]	291	[1]
Fixed Maturities Available For Sale [Member] | TBAs [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	0		0
Derivative Fair Value, Asset	31		0
Notional Value/Payment Provision			0
Accounts Payable Future Policy Benefits [Member] | Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	($716)	[3]	($663)	[3]
[1]	(1) Includes fair value of embedded derivatives.
[2]	(2) Related to GMDB and GLB blocks of business.
[3]	(3) Includes both future policy benefits reserves and fair value derivative adjustment. Refer to Note 5 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.

Recovered_Sheet4

Commitments, Contingencies, And Guarantees (Net Realized Gains (Losses) Of Derivative Instrument Activity In Consolidated Statement Of Operations) (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	($56)		($94)
Foreign Exchange Future [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	25		-3
All Other Futures Contracts And Options [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	-29		-22
Convertibles and Bonds with Warrants Attached [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	5	[1]	0	[1]
Investment And Embedded Derivative Instruments [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	1		-25
Guaranteed Living Benefits [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	-45	[2]	-48	[2]
Single-Stock Future [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	-11	[3]	-17	[3]
Options On Equity Market Indices [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	-1	[3]	-2	[3]
Guaranteed Living Benefit And Other Derivative Instruments [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	-57		-69
Other Derivatives [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	$0		($2)
[1]	(1) Includes embedded derivatives.
[2]	(2) Excludes foreign exchange gains (losses) related to GLB
[3]	(3) Related to GMDB and GLB blocks of business.

Commitments_Contingencies_And_2

Commitments, Contingencies, And Guarantees (Narrative) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Carrying value of limited partnerships and partially-owned investment companies included in other investments	$2,200,000,000
Funding commitments relating to limited partnerships and partially-owned investment companies	992,000,000
Repurchase obligations	1,402,000,000	1,402,000,000
Securities lending payable	1,034,000,000	1,331,000,000
Securities lending collateral	1,033,000,000	1,330,000,000
Unrecognized tax benefits	23,000,000
Derivative liability subject to a master netting agreement	$4,000,000	$34,000,000

Shareholders_equity_Shareholde1

Shareholders' equity Shareholders' equity (Details)

3 Months Ended

3 Months Ended

1 Months Ended

3 Months Ended

Mar. 31, 2015

Mar. 31, 2015

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2014

31-May-14

31-May-13

Mar. 31, 2015

Jan. 01, 2015

Apr. 28, 2015

Mar. 31, 2014

Nov. 30, 2013

USD ($)

CHF

USD ($)

CHF

CHF

USD ($)

USD ($)

2015 Stock Repurchase Plan [Member]

2015 Stock Repurchase Plan [Member]

2015 Stock Repurchase Plan [Member]

November 2013 Stock Repurchase Plan [Member]

November 2013 Stock Repurchase Plan [Member]

USD ($)

USD ($)

Subsequent Event [Member]

USD ($)

USD ($)

USD ($)

Equity, Class of Treasury Stock [Line Items]

Common Shares repurchased

$340,000,000

$149,000,000

$332,000,000

Repurchase of outstanding common shares, shares

3,027,463

1,351,820

3,487,882

Share repurchase authorization remains

1,160,000,000

1,011,000,000

1,612,000,000

Common Shares in treasury, shares

15,747,650

15,747,650

14,172,726

Stock repurchase program, authorized amount

$1,500,000,000

$2,000,000,000

Annual dividend per share approved by shareholders

$2.60

$2.04

Dividends Declared From Additional Paid In Capital

$0.24

0.2

Increase to dividend approved by shareholders in January

$0.12

Dividends declared per common share

$0.65

0.62

$0.75

0.65

Par Value Reduction

$0.65

0.62

$0.51

0.45

Common Stock, Dividend Rate, Per-Dollar-Amount

$0.65

Common Shares, par value

24.15

24.77

ShareBased_Compensation_Detail

Share-Based Compensation (Detail) (USD $)	3 Months Ended	0 Months Ended
	Mar. 31, 2015	Feb. 26, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period in years	3 years
Stock option term in years	10 years
Restricted stock award and units vesting period in years	4 years
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted		1,891,195
Weighted-average grant date fair value for stock options granted		$18.49
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards granted to employees and officers of the company		1,278,250
Grant date fair value of awards except for options granted to employees and officers of the company		$114.78
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units awarded to employees and officers of the company		290,475
Grant date fair value of awards except for options granted to employees and officers of the company		$114.78

Segment_Information_Operations

Segment Information (Operations By Segment) (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Net premiums written	$4,076	$4,185
Net premiums earned	3,927	3,970
Losses and loss expenses	2,122	2,161
Policy benefits	142	114
Policy acquisition costs	707	728
Administrative expenses	554	535
Underwriting income (loss)	402	432
Net investment income	551	553
Net realized gains (losses) including OTTI	-89	-104
Interest expense	68	71
(Gains) losses from fair value changes in separate account assets	-11	6
Other	6	-23
Other (income) expense	-5	-17
Income tax expense (benefit)	120	93
Net income (loss)	681	734
Insurance - North American P&C [Member]
Segment Reporting Information [Line Items]
Net premiums written	1,430	1,418
Net premiums earned	1,526	1,487
Losses and loss expenses	1,035	940
Policy acquisition costs	161	159
Administrative expenses	171	161
Underwriting income (loss)	159	227
Net investment income	263	270
Net realized gains (losses) including OTTI	-6	-9
Interest expense	2	3
Other	-7	-20
Income tax expense (benefit)	80	83
Net income (loss)	341	422
Insurance - North American Agriculture [Member]
Segment Reporting Information [Line Items]
Underwriting Income Including Losses Related to Crop Derivatives		31
Net premiums written	88	194
Net premiums earned	64	103
Losses and loss expenses	22	126
Policy acquisition costs	-4	5
Administrative expenses	-1	1
Underwriting income (loss)	47	-29
Net investment income	6	7
Net realized gains (losses) including OTTI	0	-2
Interest expense	0	0
Other	8	8
Income tax expense (benefit)	10	-7
Net income (loss)	35	-25
Crop Derivative Gain or Loss		2
Insurance - Overseas General [Member]
Segment Reporting Information [Line Items]
Net premiums written	1,794	1,771
Net premiums earned	1,637	1,612
Losses and loss expenses	814	817
Policy acquisition costs	389	386
Administrative expenses	256	250
Underwriting income (loss)	178	159
Net investment income	138	132
Net realized gains (losses) including OTTI	-10	-10
Interest expense	1	1
Other	17	-6
Income tax expense (benefit)	52	37
Net income (loss)	236	249
Global Reinsurance [Member]
Segment Reporting Information [Line Items]
Net premiums written	273	308
Net premiums earned	226	284
Losses and loss expenses	99	126
Policy acquisition costs	54	67
Administrative expenses	12	14
Underwriting income (loss)	61	77
Net investment income	75	77
Net realized gains (losses) including OTTI	-11	-8
Interest expense	1	1
Other	-5	-19
Income tax expense (benefit)	8	10
Net income (loss)	121	154
Life [Member]
Segment Reporting Information [Line Items]
Life underwriting income	77
Net premiums written	491	494
Net premiums earned	474	484
Losses and loss expenses	152	151
Policy benefits	142	114
Policy acquisition costs	107	111
Administrative expenses	73	68
Underwriting income (loss)	0	40
Net investment income	66	64
Net realized gains (losses) including OTTI	-59	-76
Interest expense	1	3
(Gains) losses from fair value changes in separate account assets	-11	6
Other	-12	7
Income tax expense (benefit)	9	10
Net income (loss)	20	2
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Losses and loss expenses	0	1
Policy acquisition costs		0
Administrative expenses	43	41
Underwriting income (loss)	-43	-42
Net investment income	3	3
Net realized gains (losses) including OTTI	-3	1
Interest expense	63	63
Other	5	7
Income tax expense (benefit)	-39	-40
Net income (loss)	($72)	($68)

Segment_Information_Net_Premiu

Segment Information (Net Premiums Earned For Segment By Product) (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Property & All Other	$1,319	$1,355
Casualty	1,506	1,480
Life, Accident & Health	1,102	1,135
Net premiums earned	3,927	3,970
Insurance - North American P&C [Member]
Segment Reporting Information [Line Items]
Net premiums earned	1,526	1,487
Insurance - North American P&C [Member] | Property Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	410	405
Insurance - North American P&C [Member] | Casualty Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	1,015	981
Insurance - North American P&C [Member] | Life Accident And Health Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	101	101
Insurance - North American Agriculture [Member]
Segment Reporting Information [Line Items]
Net premiums earned	64	103
Insurance - North American Agriculture [Member] | Property Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	64	103
Insurance - North American Agriculture [Member] | Casualty Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	0	0
Insurance - North American Agriculture [Member] | Life Accident And Health Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	0	0
Insurance - Overseas General [Member]
Segment Reporting Information [Line Items]
Net premiums earned	1,637	1,612
Insurance - Overseas General [Member] | Property Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	728	693
Insurance - Overseas General [Member] | Casualty Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	382	369
Insurance - Overseas General [Member] | Life Accident And Health Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	527	550
Global Reinsurance [Member]
Segment Reporting Information [Line Items]
Net premiums earned	226	284
Global Reinsurance [Member] | Property Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	117	154
Global Reinsurance [Member] | Casualty Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	109	130
Global Reinsurance [Member] | Life Accident And Health Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	0	0
Life [Member]
Segment Reporting Information [Line Items]
Net premiums earned	474	484
Life [Member] | Property Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	0	0
Life [Member] | Casualty Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	0	0
Life [Member] | Life Accident And Health Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	$474	$484

Earnings_Per_Share_Detail

Earnings Per Share (Detail) (USD $)	3 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Net income	$681	$734
Weighted-average shares outstanding	328,212,376	338,869,562
Share-based compensation plans	3,480,344	3,171,174
Weighted-average shares outstanding and assumed conversions	331,692,720	342,040,736
Basic earnings per share (US$ per share)	$2.08	$2.16
Diluted earnings per share (US$ per share)	$2.05	$2.14
Potential anti-dilutive share conversions	715,148	657,182

Recovered_Sheet5

Information Provided In Connection With Outstanding Debt Of Subsidiaries (Condensed Consolidating Balance Sheet) (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014		Mar. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Condensed Financial Statements, Captions [Line Items]
Investments	$63,894		$62,904
Cash	948	[1],[2]	655	[1],[3]	847	[4]	579	[4]
Insurance and reinsurance balances receivable	5,026		5,426
Reinsurance recoverable on losses and loss expenses	11,588		11,992
Reinsurance recoverable on policy benefits	215		217
Value of business acquired	440		466
Goodwill and other intangible assets	5,516		5,724
Investments in subsidiaries	0		0
Due from subsidiaries and affiliates, net	0		0
Other assets	10,771		10,864
Total assets	98,398		98,248
Unpaid losses and loss expenses	37,326		38,315
Unearned premiums	8,182		8,222
Future policy benefits	4,744		4,754
Due to subsidiaries and affiliates, net	0		0
Short-term debt	2,552		2,552
Affiliated notional cash pooling programs	0		0
Long-term debt	4,157		3,357
Trust preferred securities	309		309
Other liabilities	11,426		11,152
Total liabilities	68,696		68,661
Total shareholders' equity	29,702		29,587		29,369
Total liabilities and shareholders’ equity	98,398		98,248
ACE Limited (Parent Guarantor)
Condensed Financial Statements, Captions [Line Items]
Investments	31		30
Cash	2	[1],[2]	0	[1],[3]	25	[4]	0	[4]
Insurance and reinsurance balances receivable	0		0
Reinsurance recoverable on losses and loss expenses	0		0
Reinsurance recoverable on policy benefits	0		0
Value of business acquired	0		0
Goodwill and other intangible assets	0		0
Investments in subsidiaries	29,798		29,497
Due from subsidiaries and affiliates, net	233		583
Other assets	4		4
Total assets	30,068		30,114
Unpaid losses and loss expenses	0		0
Unearned premiums	0		0
Future policy benefits	0		0
Due to subsidiaries and affiliates, net	0		0
Short-term debt	0		0
Affiliated notional cash pooling programs	78	[2]	246	[3]
Long-term debt	0		0
Trust preferred securities	0		0
Other liabilities	288		281
Total liabilities	366		527
Total shareholders' equity	29,702		29,587
Total liabilities and shareholders’ equity	30,068		30,114
ACE INA Holdings Inc (Subsidiary Issuer)
Condensed Financial Statements, Captions [Line Items]
Investments	10		225
Cash	366	[1],[2]	1	[1],[3]	1	[4]	16	[4]
Insurance and reinsurance balances receivable	0		0
Reinsurance recoverable on losses and loss expenses	0		0
Reinsurance recoverable on policy benefits	0		0
Value of business acquired	0		0
Goodwill and other intangible assets	0		0
Investments in subsidiaries	18,767		18,762
Due from subsidiaries and affiliates, net	0		0
Other assets	291		295
Total assets	19,434		19,283
Unpaid losses and loss expenses	0		0
Unearned premiums	0		0
Future policy benefits	0		0
Due to subsidiaries and affiliates, net	103		422
Short-term debt	1,150		1,150
Affiliated notional cash pooling programs	0	[2]	309	[3]
Long-term debt	4,145		3,345
Trust preferred securities	309		309
Other liabilities	1,434		1,404
Total liabilities	7,141		6,939
Total shareholders' equity	12,293		12,344
Total liabilities and shareholders’ equity	19,434		19,283
Other ACE Limited Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Investments	63,853		62,649
Cash	658	[1],[2]	1,209	[1],[3]	1,206	[4]	748	[4]
Insurance and reinsurance balances receivable	5,746		6,178
Reinsurance recoverable on losses and loss expenses	20,292		20,992
Reinsurance recoverable on policy benefits	1,171		1,194
Value of business acquired	440		466
Goodwill and other intangible assets	5,516		5,724
Investments in subsidiaries	0		0
Due from subsidiaries and affiliates, net	0		0
Other assets	14,088		14,196
Total assets	111,764		112,608
Unpaid losses and loss expenses	45,518		46,770
Unearned premiums	9,912		9,958
Future policy benefits	5,700		5,731
Due to subsidiaries and affiliates, net	130		161
Short-term debt	1,402		1,402
Affiliated notional cash pooling programs	0	[2]	0	[3]
Long-term debt	12		12
Trust preferred securities	0		0
Other liabilities	12,818		12,659
Total liabilities	75,492		76,693
Total shareholders' equity	36,272		35,915
Total liabilities and shareholders’ equity	111,764		112,608
Consolidating Adjustments and Eliminations
Condensed Financial Statements, Captions [Line Items]
Investments	0		0
Cash	-78	[1],[2]	-555	[1],[3]	-385	[4]	-185	[4]
Insurance and reinsurance balances receivable	-720		-752
Reinsurance recoverable on losses and loss expenses	-8,704		-9,000
Reinsurance recoverable on policy benefits	-956		-977
Value of business acquired	0		0
Goodwill and other intangible assets	0		0
Investments in subsidiaries	-48,565		-48,259
Due from subsidiaries and affiliates, net	-233		-583
Other assets	-3,612		-3,631
Total assets	-62,868		-63,757
Unpaid losses and loss expenses	-8,192		-8,455
Unearned premiums	-1,730		-1,736
Future policy benefits	-956		-977
Due to subsidiaries and affiliates, net	-233		-583
Short-term debt	0		0
Affiliated notional cash pooling programs	-78	[2]	-555	[3]
Long-term debt	0		0
Trust preferred securities	0		0
Other liabilities	-3,114		-3,192
Total liabilities	-14,303		-15,498
Total shareholders' equity	-48,565		-48,259
Total liabilities and shareholders’ equity	($62,868)		($63,757)
[1]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015 and December 31, 2014, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[2]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[3]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2014, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[4]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2014 and December 31, 2013, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

Recovered_Sheet6

Information Provided In Connection With Outstanding Debt Of Subsidiaries (Condensed Consolidating Statement Of Operations) (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written	$4,076	$4,185
Net premiums earned	3,927	3,970
Net investment income	551	553
Equity in earnings of subsidiaries	0	0
Net realized gains (losses) including OTTI	-89	-104
Losses and loss expenses	2,122	2,161
Policy benefits	142	114
Policy acquisition costs and administrative expenses	1,261	1,263
Interest (income) expense	68	71
Other (income) expense	-5	-17
Income tax expense (benefit)	120	93
Net income (loss)	681	734
Comprehensive income (loss)	642	1,108
ACE Limited (Parent Guarantor)
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written	0	0
Net premiums earned	0	0
Net investment income	1	0
Equity in earnings of subsidiaries	648	702
Net realized gains (losses) including OTTI	0	0
Losses and loss expenses	0	0
Policy benefits	0	0
Policy acquisition costs and administrative expenses	14	17
Interest (income) expense	-8	-10
Other (income) expense	-41	-42
Income tax expense (benefit)	3	3
Net income (loss)	681	734
Comprehensive income (loss)	642	1,108
ACE INA Holdings Inc (Subsidiary Issuer)
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written	0	0
Net premiums earned	0	0
Net investment income	1	0
Equity in earnings of subsidiaries	204	180
Net realized gains (losses) including OTTI	0	-1
Losses and loss expenses	0	0
Policy benefits	0	0
Policy acquisition costs and administrative expenses	6	6
Interest (income) expense	69	71
Other (income) expense	-3	14
Income tax expense (benefit)	-26	-30
Net income (loss)	159	118
Comprehensive income (loss)	24	266
Other ACE Limited Subsidiaries
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written	4,076	4,185
Net premiums earned	3,927	3,970
Net investment income	549	553
Equity in earnings of subsidiaries	0	0
Net realized gains (losses) including OTTI	-89	-103
Losses and loss expenses	2,122	2,161
Policy benefits	142	114
Policy acquisition costs and administrative expenses	1,241	1,240
Interest (income) expense	7	10
Other (income) expense	39	11
Income tax expense (benefit)	143	120
Net income (loss)	693	764
Comprehensive income (loss)	654	1,138
Consolidating Adjustments and Eliminations
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written	0	0
Net premiums earned	0	0
Net investment income	0	0
Equity in earnings of subsidiaries	-852	-882
Net realized gains (losses) including OTTI	0	0
Losses and loss expenses	0	0
Policy benefits	0	0
Policy acquisition costs and administrative expenses	0	0
Interest (income) expense	0	0
Other (income) expense	0	0
Income tax expense (benefit)	0	0
Net income (loss)	-852	-882
Comprehensive income (loss)	($678)	($1,404)

Information_Provided_In_Connec2

Information Provided In Connection With Outstanding Debt Of Subsidiaries (Condensed Consolidating Statement Of Cash Flows) (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net cash flows from operating activities	$1,075		$1,250
Purchases of fixed maturities available for sale	-4,336		-3,522
Purchases of fixed maturities held to maturity	-21		-30
Purchases of equity securities	-39		-37
Sales of fixed maturities available for sale	2,002		2,208
Sales of equity securities	28		27
Maturities and redemptions of fixed maturities available for sale	1,481		1,550
Maturities and redemptions of fixed maturities held to maturity	324		212
Net change in short-term investments	-255		-765
Net derivative instruments settlements	-51		-96
Cash Acquired from Acquisition	0
Other	-153		-50
Net cash flows used for investing activities	-1,020		-503
Dividends paid on Common Shares	-214		-214
Common Shares repurchased	-347		-335
Proceeds from issuance of long-term debt	800		0
Proceeds from issuance of short-term debt	477		426
Repayments of Short-term Debt	-477		-426
Proceeds from share-based compensation plans, including windfall tax benefits	39		40
Advances To From Affiliates Financing Activities	0		0
Net proceeds from (payments to) affiliated notional cash pooling program	0		0
Policyholder contract deposits	101		51
Policyholder contract withdrawals	-40		-14
Other	-6		0
Net cash flows (used for) from financing activities	333		-472
Effect of foreign currency rate changes on cash and cash equivalents	-95		-7
Net increase in cash	293		268
Cash – beginning of period	655	[1],[2]	579	[3]
Cash – end of period	948	[1],[4]	847	[3]
ACE Limited (Parent Guarantor)
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net cash flows from operating activities	48		57
Purchases of fixed maturities available for sale	0		0
Purchases of fixed maturities held to maturity	0		0
Purchases of equity securities	0		0
Sales of fixed maturities available for sale	0		0
Sales of equity securities	0		0
Maturities and redemptions of fixed maturities available for sale	0		0
Maturities and redemptions of fixed maturities held to maturity	0		0
Net change in short-term investments	0		0
Net derivative instruments settlements	0		0
Other	0		0
Net cash flows used for investing activities	0		0
Dividends paid on Common Shares	-214		-214
Common Shares repurchased	0		0
Proceeds from issuance of long-term debt	0
Proceeds from issuance of short-term debt	0		0
Repayments of Short-term Debt	0
Proceeds from share-based compensation plans, including windfall tax benefits	0		0
Advances To From Affiliates Financing Activities	336		367
Net proceeds from (payments to) affiliated notional cash pooling program	-168	[1]	-185	[3]
Policyholder contract deposits	0		0
Policyholder contract withdrawals	0		0
Other	0
Net cash flows (used for) from financing activities	-46		-32
Effect of foreign currency rate changes on cash and cash equivalents	0		0
Net increase in cash	2		25
Cash – beginning of period	0	[1],[2]	0	[3]
Cash – end of period	2	[1],[4]	25	[3]
ACE INA Holdings Inc (Subsidiary Issuer)
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net cash flows from operating activities	4		-13
Purchases of fixed maturities available for sale	0		0
Purchases of fixed maturities held to maturity	0		0
Purchases of equity securities	0		0
Sales of fixed maturities available for sale	0		0
Sales of equity securities	0		0
Maturities and redemptions of fixed maturities available for sale	0		0
Maturities and redemptions of fixed maturities held to maturity	0		0
Net change in short-term investments	216		-8
Net derivative instruments settlements	0		-9
Other	0		-3
Net cash flows used for investing activities	216		-20
Dividends paid on Common Shares	0		0
Common Shares repurchased	0		0
Proceeds from issuance of long-term debt	800
Proceeds from issuance of short-term debt	0		0
Repayments of Short-term Debt	0
Proceeds from share-based compensation plans, including windfall tax benefits	0		0
Advances To From Affiliates Financing Activities	-340		-367
Net proceeds from (payments to) affiliated notional cash pooling program	-309	[1]	385	[3]
Policyholder contract deposits	0		0
Policyholder contract withdrawals	0		0
Other	-6
Net cash flows (used for) from financing activities	145		18
Effect of foreign currency rate changes on cash and cash equivalents	0		0
Net increase in cash	365		-15
Cash – beginning of period	1	[1],[2]	16	[3]
Cash – end of period	366	[1],[4]	1	[3]
Other ACE Limited Subsidiaries
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net cash flows from operating activities	1,023		1,206
Purchases of fixed maturities available for sale	-4,336		-3,522
Purchases of fixed maturities held to maturity	-21		-30
Purchases of equity securities	-39		-37
Sales of fixed maturities available for sale	2,002		2,208
Sales of equity securities	28		27
Maturities and redemptions of fixed maturities available for sale	1,481		1,550
Maturities and redemptions of fixed maturities held to maturity	324		212
Net change in short-term investments	-471		-757
Net derivative instruments settlements	-51		-87
Other	-153		-47
Net cash flows used for investing activities	-1,236		-483
Dividends paid on Common Shares	0		0
Common Shares repurchased	-347		-335
Proceeds from issuance of long-term debt	0
Proceeds from issuance of short-term debt	477		426
Repayments of Short-term Debt	-477
Proceeds from share-based compensation plans, including windfall tax benefits	39		40
Advances To From Affiliates Financing Activities	4		0
Net proceeds from (payments to) affiliated notional cash pooling program	0	[1]	0	[3]
Policyholder contract deposits	101		51
Policyholder contract withdrawals	-40		-14
Other	0
Net cash flows (used for) from financing activities	-243		-258
Effect of foreign currency rate changes on cash and cash equivalents	-95		-7
Net increase in cash	-551		458
Cash – beginning of period	1,209	[1],[2]	748	[3]
Cash – end of period	658	[1],[4]	1,206	[3]
Consolidating Adjustments and Eliminations
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net cash flows from operating activities	0		0
Purchases of fixed maturities available for sale	0		0
Purchases of fixed maturities held to maturity	0		0
Purchases of equity securities	0		0
Sales of fixed maturities available for sale	0		0
Sales of equity securities	0		0
Maturities and redemptions of fixed maturities available for sale	0		0
Maturities and redemptions of fixed maturities held to maturity	0		0
Net change in short-term investments	0		0
Net derivative instruments settlements	0		0
Other	0		0
Net cash flows used for investing activities	0		0
Dividends paid on Common Shares	0		0
Common Shares repurchased	0		0
Proceeds from issuance of long-term debt	0
Proceeds from issuance of short-term debt	0		0
Repayments of Short-term Debt	0
Proceeds from share-based compensation plans, including windfall tax benefits	0		0
Advances To From Affiliates Financing Activities	0		0
Net proceeds from (payments to) affiliated notional cash pooling program	477	[1]	-200	[3]
Policyholder contract deposits	0		0
Policyholder contract withdrawals	0		0
Other	0
Net cash flows (used for) from financing activities	477		-200
Effect of foreign currency rate changes on cash and cash equivalents	0		0
Net increase in cash	477		-200
Cash – beginning of period	-555	[1],[2]	-185	[3]
Cash – end of period	($78)	[1],[4]	($385)	[3]
[1]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015 and December 31, 2014, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[2]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2014, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[3]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2014 and December 31, 2013, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[4]	ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At March 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.