Information provided in connection with outstanding debt of subsidiaries (Condensed Consolidating Statement Of Operations and Comprehensive Income) (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written									$ 17,025,000,000	$ 16,075,000,000	$ 15,372,000,000
Net premiums earned	4,363,000,000	4,610,000,000	4,067,000,000	3,573,000,000	3,848,000,000	4,665,000,000	3,783,000,000	3,381,000,000	16,613,000,000	15,677,000,000	15,387,000,000
Net investment income	557,000,000	522,000,000	534,000,000	531,000,000	567,000,000	533,000,000	537,000,000	544,000,000	2,144,000,000	2,181,000,000	2,242,000,000
Equity in earnings of subsidiaries
Net realized gains (losses) including OTTI	154,000,000	40,000,000	104,000,000	206,000,000	272,000,000	(60,000,000)	(394,000,000)	260,000,000	504,000,000	78,000,000	(795,000,000)
Losses and loss expenses	2,517,000,000	2,655,000,000	2,250,000,000	1,926,000,000	2,683,000,000	3,047,000,000	2,119,000,000	1,804,000,000	9,348,000,000	9,653,000,000	9,520,000,000
Policy benefits	136,000,000	138,000,000	110,000,000	131,000,000	142,000,000	130,000,000	102,000,000	147,000,000	515,000,000	521,000,000	401,000,000
Policy acquisition costs and administrative expenses									4,870,000,000	4,542,000,000	4,540,000,000
Interest (income) expense									275,000,000	250,000,000	250,000,000
Other (income) expense									15,000,000	(6,000,000)	81,000,000
Income tax expense									480,000,000	270,000,000	502,000,000
Net income (loss)	998,000,000	916,000,000	891,000,000	953,000,000	765,000,000	640,000,000	328,000,000	973,000,000	3,758,000,000	2,706,000,000	1,540,000,000
Comprehensive income									2,023,000,000	3,682,000,000	1,857,000,000
ACE limited (Parent Gurantor)
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written											0
Net premiums earned											0
Net investment income									2,000,000	1,000,000	2,000,000
Equity in earnings of subsidiaries									3,580,000,000	2,590,000,000	1,459,000,000
Net realized gains (losses) including OTTI									0	17,000,000	(4,000,000)
Losses and loss expenses											0
Policy benefits											0
Policy acquisition costs and administrative expenses									60,000,000	62,000,000	69,000,000
Interest (income) expense									(32,000,000)	(33,000,000)	37,000,000
Other (income) expense									(221,000,000)	(137,000,000)	125,000,000
Income tax expense									17,000,000	10,000,000	10,000,000
Net income (loss)									3,758,000,000	2,706,000,000	1,540,000,000
Comprehensive income									2,023,000,000	3,682,000,000	1,857,000,000
ACE INA Holdings Inc. (Subsidiary Issuer)
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written											0
Net premiums earned											0
Net investment income											2,000,000
Equity in earnings of subsidiaries											989,000,000
Net realized gains (losses) including OTTI											0
Losses and loss expenses											0
Policy benefits											0
Policy acquisition costs and administrative expenses											37,000,000
Interest (income) expense											(266,000,000)
Other (income) expense											(21,000,000)
Income tax expense											(103,000,000)
Net income (loss)											770,000,000
Comprehensive income											1,077,000,000
Other ACE Limited Subsidiaries and Eliminations
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written											15,372,000,000
Net premiums earned											15,387,000,000
Net investment income											2,238,000,000
Equity in earnings of subsidiaries											0
Net realized gains (losses) including OTTI											(791,000,000)
Losses and loss expenses											9,520,000,000
Policy benefits											401,000,000
Policy acquisition costs and administrative expenses											4,434,000,000
Interest (income) expense											(21,000,000)
Other (income) expense											(185,000,000)
Income tax expense											595,000,000
Net income (loss)											1,678,000,000	[1]
Comprehensive income											1,994,000,000
Consolidating Adjustments
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written											0
Net premiums earned											0
Net investment income											0
Equity in earnings of subsidiaries									(4,522,000,000)	(3,501,000,000)	(2,448,000,000)
Net realized gains (losses) including OTTI											0
Losses and loss expenses											0
Policy benefits											0
Policy acquisition costs and administrative expenses											0
Interest (income) expense											0
Other (income) expense											0
Income tax expense											0
Net income (loss)									(4,522,000,000)	(3,501,000,000)	(2,448,000,000)	[2]
Comprehensive income									(1,821,000,000)	(4,933,000,000)	(3,071,000,000)
ACE INA Holdings Inc. (Subsidiary Issuer)
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written
Net premiums earned
Net investment income									3,000,000	3,000,000
Equity in earnings of subsidiaries									942,000,000	911,000,000
Net realized gains (losses) including OTTI									(2,000,000)
Losses and loss expenses
Policy benefits
Policy acquisition costs and administrative expenses									19,000,000	28,000,000
Interest (income) expense									270,000,000	235,000,000
Other (income) expense									27,000,000	9,000,000
Income tax expense									(108,000,000)	(110,000,000)
Net income (loss)									735,000,000	752,000,000
Comprehensive income									(230,000,000)	1,209,000,000
Other ACE Limited Subsidiaries and Eliminations
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written									17,025,000,000	16,075,000,000
Net premiums earned									16,613,000,000	15,677,000,000
Net investment income									2,139,000,000	2,177,000,000
Equity in earnings of subsidiaries
Net realized gains (losses) including OTTI									506,000,000	61,000,000
Losses and loss expenses									9,348,000,000	9,653,000,000
Policy benefits									515,000,000	521,000,000
Policy acquisition costs and administrative expenses									4,791,000,000	4,452,000,000
Interest (income) expense									37,000,000	48,000,000
Other (income) expense									209,000,000	122,000,000
Income tax expense									571,000,000	370,000,000
Net income (loss)									3,787,000,000	2,749,000,000
Comprehensive income									2,051,000,000	3,724,000,000
Scenario, Previously Reported
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written										16,075,000,000	15,372,000,000
Net premiums earned										15,677,000,000	15,387,000,000
Net investment income										2,181,000,000	2,242,000,000
Equity in earnings of subsidiaries
Net realized gains (losses) including OTTI										78,000,000	(795,000,000)
Losses and loss expenses										9,653,000,000	9,520,000,000
Policy benefits										521,000,000	401,000,000
Policy acquisition costs and administrative expenses										4,542,000,000	4,540,000,000
Interest (income) expense										250,000,000	250,000,000
Other (income) expense										(6,000,000)	81,000,000
Income tax expense										270,000,000	502,000,000
Net income (loss)										2,706,000,000	1,540,000,000
Comprehensive income										3,682,000,000
Scenario, Previously Reported | ACE limited (Parent Gurantor)
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written											0
Net premiums earned											0
Net investment income										1,000,000	2,000,000
Equity in earnings of subsidiaries										2,590,000,000	1,459,000,000
Net realized gains (losses) including OTTI										17,000,000	(4,000,000)
Losses and loss expenses											0
Policy benefits											0
Policy acquisition costs and administrative expenses										62,000,000	69,000,000
Interest (income) expense										(33,000,000)	37,000,000
Other (income) expense										(137,000,000)	125,000,000
Income tax expense										10,000,000	10,000,000
Net income (loss)										2,706,000,000	1,540,000,000
Comprehensive income										3,682,000,000	1,857,000,000
Scenario, Previously Reported | ACE INA Holdings Inc. (Subsidiary Issuer)
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written											9,081,000,000
Net premiums earned											9,082,000,000
Net investment income											1,096,000,000
Equity in earnings of subsidiaries											0
Net realized gains (losses) including OTTI											62,000,000
Losses and loss expenses											5,889,000,000
Policy benefits											192,000,000
Policy acquisition costs and administrative expenses											2,561,000,000
Interest (income) expense											(267,000,000)
Other (income) expense											(143,000,000)
Income tax expense											418,000,000
Net income (loss)											770,000,000
Comprehensive income											1,077,000,000
Scenario, Previously Reported | Other ACE Limited Subsidiaries and Eliminations
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written											6,291,000,000
Net premiums earned											6,305,000,000
Net investment income											1,144,000,000
Equity in earnings of subsidiaries											0
Net realized gains (losses) including OTTI											(853,000,000)
Losses and loss expenses											3,631,000,000
Policy benefits											209,000,000
Policy acquisition costs and administrative expenses											1,910,000,000
Interest (income) expense											(20,000,000)
Other (income) expense											(63,000,000)
Income tax expense											74,000,000
Net income (loss)											689,000,000	[1]
Comprehensive income											382,000,000
Scenario, Previously Reported | Consolidating Adjustments
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written											0
Net premiums earned											0
Net investment income											0
Equity in earnings of subsidiaries										(2,590,000,000)	(1,459,000,000)
Net realized gains (losses) including OTTI											0
Losses and loss expenses											0
Policy benefits											0
Policy acquisition costs and administrative expenses											0
Interest (income) expense											0
Other (income) expense											0
Income tax expense											0
Net income (loss)										(2,590,000,000)	(1,459,000,000)	[2]
Comprehensive income										(2,590,000,000)	(1,459,000,000)
Scenario, Previously Reported | ACE INA Holdings Inc. (Subsidiary Issuer)
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written										9,466,000,000
Net premiums earned										9,194,000,000
Net investment income										1,048,000,000
Equity in earnings of subsidiaries
Net realized gains (losses) including OTTI										121,000,000
Losses and loss expenses										6,211,000,000
Policy benefits										309,000,000
Policy acquisition costs and administrative expenses										2,564,000,000
Interest (income) expense										257,000,000
Other (income) expense										77,000,000
Income tax expense										193,000,000
Net income (loss)										752,000,000
Comprehensive income										1,209,000,000
Scenario, Previously Reported | Other ACE Limited Subsidiaries and Eliminations
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Line Items]
Net premiums written										6,609,000,000
Net premiums earned										6,483,000,000
Net investment income										1,132,000,000
Equity in earnings of subsidiaries
Net realized gains (losses) including OTTI										(60,000,000)
Losses and loss expenses										3,442,000,000
Policy benefits										212,000,000
Policy acquisition costs and administrative expenses										1,916,000,000
Interest (income) expense										26,000,000
Other (income) expense										54,000,000
Income tax expense										67,000,000
Net income (loss)										1,838,000,000
Comprehensive income										$ 1,381,000,000

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

[2] Includes ACE Limited parent company eliminations.