Information Provided In Connection With Outstanding Debt Of Subsidiaries (Condensed Consolidating Balance Sheet) (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013		Jun. 30, 2013		Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Investments	$ 63,620		$ 60,928
Cash	594	[1],[2]	579	[1],[3]	679	[4]	615	[4]
Insurance and reinsurance balances receivable	5,316		5,026
Reinsurance recoverable on losses and loss expenses	10,768		11,227
Reinsurance recoverable on policy benefits	234		218
Value of business acquired	514		536
Goodwill and other intangible assets	5,522		5,404
Other assets	10,879		10,592
Total assets	97,447		94,510
Unpaid losses and loss expenses	37,177		37,443
Unearned premiums	8,296		7,539
Future policy benefits	4,778		4,615
Short-term debt	1,851		1,901
Long-term debt	4,057		3,807
Trust preferred securities	309		309
Other liabilities	10,654		10,071
Total liabilities	67,122		65,685
Total shareholders' equity	30,325		28,825		27,295
Total liabilities and shareholders’ equity	97,447		94,510
Scenario, Previously Reported [Member]
Condensed Financial Statements, Captions [Line Items]
Cash					679		615
ACE Limited (Parent Guarantor)
Condensed Financial Statements, Captions [Line Items]
Investments	33		32
Cash	44	[1],[2]	0	[1],[3]	0	[4]	103	[4]
Investments in subsidiaries	30,207		28,351
Due from subsidiaries and affiliates, net	305		844
Other assets	4		5
Total assets	30,593		29,232
Affiliated notional cash pooling programs	0	[2]	185	[3]
Trust preferred securities			0
Other liabilities	268		222
Total liabilities	268		407
Total shareholders' equity	30,325		28,825
Total liabilities and shareholders’ equity	30,593		29,232
ACE Limited (Parent Guarantor) | Scenario, Previously Reported [Member]
Condensed Financial Statements, Captions [Line Items]
Cash					(513)	[5]	103	[5]
ACE INA Holdings Inc (Subsidiary Issuer)
Condensed Financial Statements, Captions [Line Items]
Investments	11		10
Cash	1	[1],[2]	16	[1],[3]	3	[4]	2	[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	18,946		18,105
Other assets	295		258
Total assets	19,253		18,389
Unpaid losses and loss expenses	0		0
Unearned premiums	0		0
Future policy benefits	0		0
Due to subsidiaries and affiliates, net	78		714
Short-term debt	450		500
Affiliated notional cash pooling programs	477	[2]	0	[3]
Long-term debt	4,045		3,795
Trust preferred securities	309		309
Other liabilities	1,418		1,318
Total liabilities	6,777		6,636
Total shareholders' equity	12,476		11,753
Total liabilities and shareholders’ equity	19,253		18,389
ACE INA Holdings Inc (Subsidiary Issuer) | Scenario, Previously Reported [Member]
Condensed Financial Statements, Captions [Line Items]
Cash					583	[5]	515	[5]
Other ACE Limited Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Investments	63,576		60,886
Cash	1,026	[1],[2]	748	[1],[3]	1,285	[4]	859	[4]
Insurance and reinsurance balances receivable	6,169		5,835
Reinsurance recoverable on losses and loss expenses	19,609		20,057
Reinsurance recoverable on policy benefits	1,260		1,215
Value of business acquired	514		536
Goodwill and other intangible assets	5,522		5,404
Other assets	14,300		13,788
Total assets	111,976		108,469
Unpaid losses and loss expenses	45,589		45,714
Unearned premiums	10,154		9,242
Future policy benefits	5,804		5,612
Due to subsidiaries and affiliates, net	227		130
Short-term debt	1,401		1,401
Affiliated notional cash pooling programs	0	[2]	0	[3]
Long-term debt	12		12
Trust preferred securities			0
Other liabilities	12,112		11,655
Total liabilities	75,299		73,766
Total shareholders' equity	36,677		34,703
Total liabilities and shareholders’ equity	111,976		108,469
Other ACE Limited Subsidiaries | Scenario, Previously Reported [Member]
Condensed Financial Statements, Captions [Line Items]
Cash					609	[5],[6]	(3)	[5],[6]
Consolidating Adjustments and Eliminations
Condensed Financial Statements, Captions [Line Items]
Investments	0		0
Cash	(477)	[1],[2]	(185)	[1],[3]	(609)	[4]	(349)	[4]
Insurance and reinsurance balances receivable	(853)		(809)
Reinsurance recoverable on losses and loss expenses	(8,841)		(8,830)
Reinsurance recoverable on policy benefits	(1,026)		(997)
Value of business acquired	0		0
Goodwill and other intangible assets	0		0
Investments in subsidiaries	(49,153)		(46,456)
Due from subsidiaries and affiliates, net	(305)		(844)
Other assets	(3,720)		(3,459)
Total assets	(64,375)		(61,580)
Unpaid losses and loss expenses	(8,412)		(8,271)
Unearned premiums	(1,858)		(1,703)
Future policy benefits	(1,026)		(997)
Due to subsidiaries and affiliates, net	(305)		(844)
Short-term debt	0		0
Affiliated notional cash pooling programs	(477)	[2]	(185)	[3]
Long-term debt			0
Trust preferred securities			0
Other liabilities	(3,144)		(3,124)
Total liabilities	(15,222)		(15,124)
Total shareholders' equity	(49,153)		(46,456)
Total liabilities and shareholders’ equity	(64,375)		(61,580)
Consolidating Adjustments and Eliminations | Scenario, Previously Reported [Member]
Condensed Financial Statements, Captions [Line Items]
Cash					$ 0	[5],[7]	$ 0	[7]

[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 June 30, 2014 and December 31, 2013, 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 June 30, 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 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 June 30, 2013 and December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

[5] 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 June 30, 2013 and December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

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

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