Information Provided In Connection With Outstanding Debt Of Subsidiaries (Condensed Consolidating Balance Sheet) (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013		Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Investments	$ 62,045		$ 60,928
Insurance and reinsurance balances receivable	4,761		5,026
Reinsurance recoverable on losses and loss expenses	10,755		11,227
Reinsurance recoverable on policy benefits	222		218
Value of business acquired	517		536
Goodwill and other intangible assets	5,382		5,404
Other assets	10,650		10,592
Total assets	95,179		94,510
Unpaid losses and loss expenses	36,866		37,443
Unearned premiums	7,791		7,539
Future policy benefits	4,632		4,615
Short-term debt	1,901		1,901
Long-term debt	3,808		3,807
Trust preferred securities	309		309
Other liabilities	10,503		10,071
Total liabilities	65,810		65,685
Total shareholders' equity	29,369		28,825		27,942
Total liabilities and shareholders’ equity	95,179		94,510
Cash	847	[1],[2]	579	[2],[3]	855	[4]	615	[4]
Scenario, Previously Reported [Member]
Condensed Financial Statements, Captions [Line Items]
Cash					855	[5]	615
ACE Limited (Parent Guarantor)
Condensed Financial Statements, Captions [Line Items]
Investments	32		32
Investments in subsidiaries	29,075		28,351
Due from subsidiaries and affiliates, net	487		844
Other assets	3		5
Total assets	29,622		29,232
Affiliated notional cash pooling programs	0	[1]	185	[1]
Trust preferred securities			0
Other liabilities	253		222
Total liabilities	253		407
Total shareholders' equity	29,369		28,825
Total liabilities and shareholders’ equity	29,622		29,232
Cash	25	[1],[2]	0	[2],[3]	197	[4]	103	[4]
ACE Limited (Parent Guarantor) | Scenario, Previously Reported [Member]
Condensed Financial Statements, Captions [Line Items]
Cash					197	[5]	103
ACE INA Holdings Inc (Subsidiary Issuer)
Condensed Financial Statements, Captions [Line Items]
Investments	18		10
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	18,368		18,105
Other assets	256		258
Total assets	18,643		18,389
Unpaid losses and loss expenses	0		0
Unearned premiums	0		0
Future policy benefits	0		0
Due to subsidiaries and affiliates, net	367		714
Short-term debt	500		500
Affiliated notional cash pooling programs	385	[1]	0	[1]
Long-term debt	3,795		3,795
Trust preferred securities	309		309
Other liabilities	1,343		1,318
Total liabilities	6,699		6,636
Total shareholders' equity	11,944		11,753
Total liabilities and shareholders’ equity	18,643		18,389
Cash	1	[1],[2]	16	[2],[3]	489	[4]	2	[4]
ACE INA Holdings Inc (Subsidiary Issuer) | Scenario, Previously Reported [Member]
Condensed Financial Statements, Captions [Line Items]
Cash					560	[5]	515
Other ACE Limited Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Investments	61,995		60,886
Insurance and reinsurance balances receivable	5,540		5,835
Reinsurance recoverable on losses and loss expenses	19,531		20,057
Reinsurance recoverable on policy benefits	1,210		1,215
Value of business acquired	517		536
Goodwill and other intangible assets	5,382		5,404
Other assets	13,956		13,788
Total assets	109,337		108,469
Unpaid losses and loss expenses	45,173		45,714
Unearned premiums	9,584		9,242
Future policy benefits	5,620		5,612
Due to subsidiaries and affiliates, net	120		130
Short-term debt	1,401		1,401
Affiliated notional cash pooling programs	0	[1]	0	[1]
Long-term debt	13		12
Trust preferred securities			0
Other liabilities	11,927		11,655
Total liabilities	73,838		73,766
Total shareholders' equity	35,499		34,703
Total liabilities and shareholders’ equity	109,337		108,469
Cash	1,206	[1],[2]	748	[2],[3]	169	[4]	859	[4]
Other ACE Limited Subsidiaries | Scenario, Previously Reported [Member]
Condensed Financial Statements, Captions [Line Items]
Cash					98	[5],[6]	(3)	[6]
Consolidating Adjustments and Eliminations
Condensed Financial Statements, Captions [Line Items]
Investments	0		0
Insurance and reinsurance balances receivable	(779)		(809)
Reinsurance recoverable on losses and loss expenses	(8,776)		(8,830)
Reinsurance recoverable on policy benefits	(988)		(997)
Value of business acquired	0		0
Goodwill and other intangible assets	0		0
Investments in subsidiaries	(47,443)		(46,456)
Due from subsidiaries and affiliates, net	(487)		(844)
Other assets	(3,565)		(3,459)
Total assets	(62,423)		(61,580)
Unpaid losses and loss expenses	(8,307)		(8,271)
Unearned premiums	(1,793)		(1,703)
Future policy benefits	(988)		(997)
Due to subsidiaries and affiliates, net	(487)		(844)
Short-term debt	0		0
Affiliated notional cash pooling programs	(385)	[1]	(185)	[1]
Long-term debt			0
Trust preferred securities			0
Other liabilities	(3,020)		(3,124)
Total liabilities	(14,980)		(15,124)
Total shareholders' equity	(47,443)		(46,456)
Total liabilities and shareholders’ equity	(62,423)		(61,580)
Cash	(385)	[1],[2]	(185)	[2],[3]	0	[4]	(349)	[4]
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 March 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, 2014 and December 31, 2013, 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 March 31, 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 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.