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
	Mar. 31, 2025	Mar. 31, 2024
Reclassification of significant items out of Accumulated Other Comprehensive Income
Total net realized losses	$ (103)	$ (87)
Net income attributable to AIG	698	1,216
Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income attributable to AIG	(270)	(450)
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)
Net income attributable to AIG	0	(6)
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	(262)	(437)
Net income attributable to AIG	(262)	(437)
Change in retirement plan liabilities adjustment | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income attributable to AIG	(8)	(7)
Prior-service credit | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income attributable to AIG	(1)	0
Actuarial losses | Amount Reclassified from AOCI
Reclassification of significant items out of Accumulated Other Comprehensive Income
Net income attributable to AIG	$ (7)	$ (7)