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		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Reclassification of significant items out of Accumulated Other Comprehensive Income
Total net realized losses	$ (258)	$ (180)	$ (361)	$ (267)
Net income (loss) attributable to AIG	1,144	(3,977)	1,842	(2,761)
Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income (loss) attributable to AIG	(158)	(7,049)	(428)	(7,499)
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 losses	0	6	0	0
Net income (loss) attributable to AIG	0	6	0	0
Unrealized Appreciation (Depreciation) of All Other Investments | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Total net realized losses	(151)	167	(413)	(270)
Net income (loss) attributable to AIG	(151)	167	(413)	(270)
Retirement Plan Liabilities Adjustment | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income (loss) attributable to AIG	(7)	(8)	(15)	(15)
Prior-service credit | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income (loss) attributable to AIG	0	(1)	(1)	(1)
Actuarial losses | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income (loss) attributable to AIG	(7)	(7)	(14)	(14)
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	$ 0	$ (7,214)	$ 0	$ (7,214)