Segment Information - Schedule of Continuing Operations by Operating Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Net Premiums Earned	$ 23,537	$ 25,564	$ 26,765
Loss and Loss Adjustment Expenses Incurred	14,567	15,393	15,461
Amortization of DAC	3,425	3,771	3,545
General Operating Expense	5,529	5,399	6,159
Net Investment Income	4,255	3,446	2,370
Income from continuing operations before income tax expense	3,870	2,867	3,772
Interest expense	462	516	603
Changes in the fair values of equity securities, AIG's investment in Corebridge and gain on sale of shares	586	53	29
Other income (expense) - net	16	8	28
Gain (loss) on extinguishment of debt	(14)	37	(303)
Total net realized gains (losses)	(548)	(1,078)	827
Net realized losses, net investment income	8	(12)	(61)
Net realized losses, reconciliation to income (loss) from continuing operations before income tax expense	(428)	(743)	(268)
Net gain (loss) on divestitures and other	616	(29)	(153)
Non-operating litigation reserves and settlements, reconciliation to income (loss) from continuing operations before income tax expense		(1)	16
(Unfavorable) favorable prior year development and related amortization changes ceded under retroactive reinsurance agreements	(105)	62	160
Net loss reserve discount benefit (charge)	(226)	(195)	703
Pension expense related to lump sum payments to former employees		(71)	(59)
Net results of businesses in run-off, net investment income	17	21	6
Net results of businesses in run-off, net investment income, reconciliation to income (loss) from continuing operations before income tax expense	(111)	(31)	25
Integration and transaction costs associated with acquiring or divesting businesses	(39)	(6)	(12)
Restructuring and other costs	$ (745)	$ (356)	$ (423)
Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration]	General Operating Expense	General Operating Expense	General Operating Expense
Non-recurring costs related to regulatory or accounting changes	$ (18)	$ (22)	$ (26)
Net impact from elimination of international reporting lag, net investment income		1	41
Net impact from elimination of international reporting lag, reconciliation to income (loss) from continuing operations before income tax expense		12	127
Fortitude Re funds withheld assets
Segment Reporting Information [Line Items]
Net Investment Income	144	180	53
Total net realized gains (losses)	(39)	(71)	(99)
Fortitude Re funds withheld embedded derivative
Segment Reporting Information [Line Items]
Total net realized gains (losses)	(75)	(273)	1,133
Total
Segment Reporting Information [Line Items]
Net Investment Income	3,484	3,195	2,274
Income from continuing operations before income tax expense	4,324	4,321	2,869
Reportable Segments
Segment Reporting Information [Line Items]
Net Premiums Written	23,902	26,719	25,512
Net Premiums Earned	23,457	25,091	25,340
Loss and Loss Adjustment Expenses Incurred	14,038	14,775	15,407
Amortization of DAC	3,413	3,623	3,533
Other Acquisition Cost	1,137	1,279	1,365
General Operating Expense	2,952	3,065	2,987
Underwriting Income (Loss)	1,917	2,349	2,048
Net Investment Income	3,060	3,022	2,382
Income from continuing operations before income tax expense	4,977	5,371	4,430
Interest expense	(445)	(498)	(624)
Other Operations
Segment Reporting Information [Line Items]
Net Premiums Earned	0	3	937
Net Investment Income	424	186	(122)
Income from continuing operations before income tax expense	(207)	(535)	(1,000)
Elimination and consolidations
Segment Reporting Information [Line Items]
Net Premiums Earned	(3)	(5)	10
Net Investment Income		(13)	14
Income from continuing operations before income tax expense	(1)	(17)	63
North America Commercial | Reportable Segments
Segment Reporting Information [Line Items]
Net Premiums Written	8,452	11,432	10,899
Net Premiums Earned	8,172	10,233	10,444
Loss and Loss Adjustment Expenses Incurred	5,713	6,323	7,218
Amortization of DAC	824	1,371	1,381
Other Acquisition Cost	222	231	174
General Operating Expense	865	953	927
Underwriting Income (Loss)	548	1,355	744
International Commercial | Reportable Segments
Segment Reporting Information [Line Items]
Net Premiums Written	8,364	8,168	7,877
Net Premiums Earned	8,145	7,964	7,701
Loss and Loss Adjustment Expenses Incurred	4,463	4,641	4,301
Amortization of DAC	1,018	943	938
Other Acquisition Cost	342	350	378
General Operating Expense	1,095	1,028	945
Underwriting Income (Loss)	1,227	1,002	1,139
Global Personal | Reportable Segments
Segment Reporting Information [Line Items]
Net Premiums Written	7,086	7,119	6,736
Net Premiums Earned	7,140	6,894	7,195
Loss and Loss Adjustment Expenses Incurred	3,862	3,811	3,888
Amortization of DAC	1,571	1,309	1,214
Other Acquisition Cost	573	698	813
General Operating Expense	992	1,084	1,115
Underwriting Income (Loss)	$ 142	$ (8)	$ 165