BASIS OF PRESENTATION (Details 10K) $ / shares in Units, $ in Millions				3 Months Ended								12 Months Ended
	Nov. 14, 2016 USD ($)	Oct. 18, 2016 USD ($)	Sep. 16, 2016 USD ($)	Dec. 31, 2017 USD ($) item $ / shares	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) $ / shares	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) item $ / shares	Dec. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Nov. 17, 2016 USD ($)	Aug. 31, 2016 USD ($)
Basis of Presentation [Line Items]
Common stock, par value (in dollars per share) | $ / shares				$ 2.5				$ 2.5				$ 2.5	$ 2.5
Net income (loss) attributable to AIG				$ (6,660)	$ (1,739)	$ 1,130	$ 1,185	$ (3,041)	$ 462	$ 1,913	$ (183)	$ (6,084)	$ (849)	$ 2,196
Income (loss) from continuing operations before income tax expense (benefit)				875	(2,803)	1,667	1,727	(3,455)	737	2,858	(214)	1,466	(74)	3,281
Net income (loss) on sale of divested businesses				(241)	13	60	100	(194)	(128)	(225)	2	68	545	(11)
Repayments of Long-term Debt												3,698	4,082	9,805
Other Income												2,412	3,121	4,088
Income (Loss) from Continuing Operations Attributable to Noncontrolling Interest				$ (12)	26	(12)	$ 26	535	(26)	11	(20)	28	500	26
Adjustment
Basis of Presentation [Line Items]
Net income (loss) attributable to AIG								(154)
Income (loss) from continuing operations before income tax expense (benefit)								(12)
Adjusted Pre-Tax Income (Loss)								(1)
Adjustments 2015
Basis of Presentation [Line Items]
Net income (loss) attributable to AIG														(156)	$ (51)
Income (loss) from continuing operations before income tax expense (benefit)														(376)
Adjusted Pre-Tax Income (Loss)														(235)
Adjustments 2016
Basis of Presentation [Line Items]
Net income (loss) attributable to AIG									(65)	$ 66	$ 19		(174)	(67)	$ (12)
Income (loss) from continuing operations before income tax expense (benefit)													(57)
Adjusted Pre-Tax Income (Loss)													(6)
ILFC
Basis of Presentation [Line Items]
Non-cash consideration received from sale												0	0	0
NSM
Basis of Presentation [Line Items]
Total consideration																	$ 201
Net income (loss) on sale of divested businesses									$ 105
Ascot
Basis of Presentation [Line Items]
Consideration in cash													244
Total consideration			$ 1,100
Net income (loss) on sale of divested businesses			$ 162
Voting interest in subsidiary, Percent			100.00%
Ownership reflecting consideration, Percent			20.00%
United Guaranty Asia
Basis of Presentation [Line Items]
Consideration in cash					40								2,200
Non-cash consideration received from sale												$ 0	1,101	$ 0
Total consideration								$ 3,300					3,300
Net income (loss) on sale of divested businesses													$ 697
Voting interest in subsidiary, Percent								100.00%					100.00%
Dividend-in-lieu													$ 261
Cash consideration retained by buyer													40
Korea Fund
Basis of Presentation [Line Items]
Income (loss) from continuing operations before income tax expense (benefit)													464
Total consideration																$ 2,500
Repayments of Long-term Debt													1,200
Other Income													$ 1,100
Certain insurance operations
Basis of Presentation [Line Items]
Consideration in cash		$ 234			$ 168	$ 48
AIG Fuji Life Insurance
Basis of Presentation [Line Items]
Consideration in cash	$ 333
Net income (loss) on sale of divested businesses	$ (591)
Minimum
Basis of Presentation [Line Items]
Number of Countries in which the entity operates | item				80								80