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

[1] ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

[2] ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2010, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

[3] ACE maintains two notional multi-currency cash pools (Pools) with a third-party bank. Refer to Note 1 f) for additional information. At December 31, 2013 and December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

[4] Includes all other subsidiaries of ACE Limited and intercompany eliminations.

[5] Includes ACE Limited parent company eliminations and certain consolidating adjustments.