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								12 Months Ended
	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net realized gains (losses)									$ (548)	$ (1,078)	$ 827
Net income (loss) attributable to AIG	$ 898	$ 459	$ (3,977)	$ 1,216	$ 93	$ 2,027	$ 1,493	$ 30	(1,404)	3,643	10,227
Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income (loss) attributable to AIG									(7,864)	(1,091)	(1,212)
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
Net realized gains (losses)									0	(26)	7
Net income (loss) attributable to AIG									0	(26)	7
Unrealized appreciation (depreciation) of all other investments | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net realized gains (losses)									(619)	(1,036)	(1,189)
Net income (loss) attributable to AIG									(619)	(1,036)	(1,189)
Change in retirement plan liabilities adjustment | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income (loss) attributable to AIG									(31)	(29)	(30)
Prior-service credit | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income (loss) attributable to AIG									(2)	(2)	(2)
Actuarial losses | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income (loss) attributable to AIG									(29)	(27)	(28)
Corebridge deconsolidation, net of tax | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income (loss) attributable to AIG									$ (7,214)	$ 0	$ 0