Commitments, Contingencies and Guarantees (Details) Share data in Millions, unless otherwise specified	6 Months Ended				6 Months Ended		1 Months Ended		6 Months Ended									1 Months Ended						1 Months Ended			6 Months Ended	1 Months Ended	6 Months Ended		6 Months Ended						12 Months Ended	1 Months Ended			6 Months Ended	12 Months Ended
	Jun. 30, 2011	Mar. 20, 2009 Consolidated 2008 Securities Litigation	Mar. 31, 2011 ERISA Litigation II	Mar. 19, 2009 ERISA Litigation II	Jun. 30, 2011 Canadian Securities Class Action claim USD ($)	Jun. 30, 2011 Brookfield litigation related to AIGFP USD ($)	Jun. 30, 2010 Securities lending dispute with Transatlantic Holdings Inc. EUR (€)	May 31, 2010 Securities lending dispute with Transatlantic Holdings Inc. USD ($)	Jun. 30, 2011 Securities lending dispute with Transatlantic Holdings Inc. USD ($)	Jun. 29, 2010 Securities lending dispute with Transatlantic Holdings Inc.	May 24, 2010 Securities lending dispute with Transatlantic Holdings Inc.	Jun. 30, 2011 Employment litigation against AIG and AIGGRE USD ($)	Jun. 30, 2011 ALICO Life International Limited's Italian Internal Funds Suspensions USD ($)	Jun. 30, 2011 ALICO Life International Limited's Italian Internal Funds Suspensions EUR (€)	Jun. 24, 2011 ALICO Life International Limited's Italian Internal Funds Suspensions	Jun. 30, 2011 False Claims Act complaint	Feb. 25, 2010 False Claims Act complaint	Feb. 28, 2006 2006 Regulatory Settlements USD ($)	Jul. 31, 2010 Consolidated 2004 Securities Litigation USD ($)	May 27, 2011 Consolidated 2004 Securities Litigation	Dec. 13, 2010 Consolidated 2004 Securities Litigation	Jul. 14, 2010 Consolidated 2004 Securities Litigation USD ($)	Feb. 22, 2010 Consolidated 2004 Securities Litigation	Apr. 30, 2011 Workers' compensation Premium Reporting USD ($)	Jan. 31, 2011 Workers' compensation Premium Reporting	May 31, 2007 Workers' compensation Premium Reporting USD ($)	Jun. 30, 2011 Workers' compensation Premium Reporting USD ($)	Mar. 31, 2011 The Multi-District Litigation USD ($)	Jun. 30, 2011 The Multi-District Litigation	Mar. 18, 2011 The Multi-District Litigation USD ($)	Jun. 30, 2011 The Multi-District Litigation Florida	Jun. 30, 2011 The Multi-District Litigation New Jersey	Jun. 30, 2011 The Multi-District Litigation Texas USD ($)	Jun. 30, 2011 The Multi-District Litigation Kansas USD ($)	Jun. 30, 2011 Palm Tree Computer Systems, Inc. v. Ace USA USD ($)	Jun. 30, 2011 The Heritage Corp. of South Florida v. National Union Fire Ins. Co. USD ($)	Dec. 31, 2008 Other Regulatory Settlements USD ($)	Apr. 30, 2010 Regulatory Settlement Ohio Attorney General USD ($)	Dec. 31, 2010 NAIC Examination of Workers Compensation Premium Reporting USD ($)	Dec. 17, 2010 NAIC Examination of Workers Compensation Premium Reporting	Jun. 30, 2011 Caremark USD ($)	Dec. 31, 2009 Derivative complaints, State of California
Litigation and Investigations
Number of states participating in the accident and health products examination	38
Number of purported class action complaints consolidated		8		8																																					2
Motions to dismiss granted, plans at issue			1
Motions to dismiss denied, plans at issue			2
Damages claimed					$ 500,000,000		€ 17,600,000	$ 350,000,000	$ 25,500,000																																$ 3,200,000,000
Punitive damages claimed					50,000,000
Maximum contractual loss						1,400,000,000
Transatlantic, number of subsidiaries named as Claimants											2
AIG, number of subsidiaries named as Respondents										1	2
Damages claimed, amount currently due												196,000,000
Damages claimed, potential future amounts												78,000,000
Range of loss, minimum												0
Range of loss, maximum												274,000,000
Accrued loss contingency													208,000,000	143,000,000																7,000,000
Percentage of eligible policyholders who have accepted settlement offer (as a percent)															96.00%
Number of individuals (Relators) seeking to assert claims																	2
Damages sought, multiple of damages sustained																3
Payments made or placed in escrow accounts initial amount																		1,640,000,000
Portion of payments which represented fines and penalties																		225,000,000																					100,000,000
Deposits into fund under the supervision of the SEC, subsequently disbursed																		800,000,000
Workers Compensation Fund escrow, included in Other Assets																		338,000,000																					338,000,000
Settlement amount total																			725,000,000								450,000,000	37,000,000									26,000,000	9,000,000
Minimum number of conspiracies alledged																													1
Settlement amount paid under previous settlement agreements																																					4,400,000
Settlement agreement, number of states																																								50
Settlement agreement, payment of outstanding premium taxes																																							46,500,000
Settlement agreement, maximum contingent fines																																							150,000,000
Settlement agreement, amount which can be paid out of the remaining balance in Workers Compensation Fund																											191,500,000												146,500,000
Claims rejected, number of disclosure dates																							2
Claims proposed, number of disclosure dates																							6
Minimum number of disclosure dates that the shareholders possessed stock																							1
Companies acquired for common stock, number included in class																							2
Number of shareholders that filed a notice of appeal																					4
Settlement agreement, escrow																						175,000,000
Settlement agreement, escrow payment within days of court approval of settlement (in days)																						10
Minimum number of common stock offerings																						1
Settlement agreement, funding contingent upon raising cash proceeds																						550,000,000
Registered public offering of common stock (in shares)																				300
Number of parallel actions																													2
Number of separate derivative actions filed																													24
Number of complaints settled																													3
Number of states asserted antitrust law violations																													48
Employee Benefits Complaint, number of purported classes																													2
Number of consolidated actions																																			1
Number of named plaintiffs																																			2
Maximum period to submit letter since date of order by court (in days)																													30
Number of cases that have proceeded																													4		1	1	1	1
Number of claims																																		3
Damages sought, in excess																								$ 3,000,000,000		$ 1,000,000,000							$ 125,000,000	$ 75,000	$ 74,999	$ 75,000
Number of intervening plaintiffs																									7
Number of purported shareholder complaints																																										2