Basis of Presentation (Details) shares in Millions, $ in Millions				3 Months Ended								12 Months Ended
	Nov. 01, 2023 USD ($) shares	Jul. 03, 2023 USD ($)	Dec. 14, 2022 USD ($)	Dec. 31, 2024 USD ($) country	Sep. 30, 2024 USD ($)	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2024 USD ($) country	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 02, 2024 USD ($)	Sep. 04, 2023 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of countries in which the entity operates | country				200								200
Net income (loss)				$ 901	$ 457	$ (3,884)	$ 1,600	$ (473)	$ 2,747	$ 1,691	$ (87)	$ (926)	$ 3,878	$ 11,273
Disposal consideration															$ 600
Transition services period															30 months
Fronting agreement, percent															1
Parent Company
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income (loss)												3,038	2,765	2,881
Pre-tax loss on deconsolidation			$ 114
Sale of Assets | Crop Risk Services
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration for divestiture of business		$ 234
Gain (loss) on disposal of business													72
Sale of Assets | Validus Re
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration for divestiture of business	$ 2,700
Gain (loss) on disposal of business													(78)
Share consideration received on transaction (in shares) | shares	1.3
Value of share consideration received on transaction	$ 290
Percent of reserves retained, difference between reserves as of the closing date and reserve development following closing date for such losses	0.95
Contingent consideration	$ 130
Reimbursement to be received														400
Reserve balance														3,043
Expected premium to be paid																$ 80
Sale of Assets | Global Personal Travel Insurance
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on disposal of business												511
Total AIG Share- holders' Equity
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income (loss)												$ (1,404)	$ 3,643	10,227
Cumulative effect of change in accounting principle | Total AIG Share- holders' Equity
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income (loss)														$ 100