Equity - Schedule of effect of the reclassification of significant items out of accumulated other comprehensive income on the respective line items in the Consolidated Statements of Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Reclassification of significant items out of Accumulated Other Comprehensive Income
Total net realized gains (losses)	$ 1,081	$ 2,572	$ (1,125)	$ 8,783
Net income (loss) attributable to AIG	2,027	2,748	3,550	9,675
Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income (loss) attributable to AIG	(169)	(139)	(979)	(897)
Unrealized appreciation (depreciation) of fixed maturity securities on which allowance for credit losses was taken | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Total net realized gains (losses)		17	(23)	9
Unrealized appreciation (depreciation) of all other investments | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Total net realized gains (losses)	(163)	(148)	(933)	(883)
Change in retirement plan liabilities adjustment | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Total net realized gains (losses)	(6)	(8)	(23)	(23)
Prior-service credit | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Total net realized gains (losses)	(1)	(1)	(2)	(2)
Actuarial losses | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Total net realized gains (losses)	$ (5)	$ (7)	$ (21)	$ (21)