Basis of Presentation (Details) $ / shares in Units, shares in Millions, $ in Millions			3 Months Ended		12 Months Ended						24 Months Ended
	Feb. 17, 2026 USD ($) $ / shares shares	Feb. 06, 2026 USD ($)	Mar. 31, 2026 USD ($) country	Mar. 31, 2025 USD ($)	Dec. 31, 2028	Dec. 31, 2027	Dec. 31, 2026	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2025 USD ($)
Summary of Significant Accounting Policies [Line Items]
Number of countries in which the entity operates | country			200
Goodwill			$ 3,418									$ 3,435
Income before income tax expense			$ 987	$ 960
Revision of Prior Period, Adjustment
Summary of Significant Accounting Policies [Line Items]
Net income attributable to AIG				51				$ (68)	$ 19	$ 23	$ 77
Income before income tax expense				$ 140					$ 34	$ 42	$ 143
Corebridge Financial Inc
Summary of Significant Accounting Policies [Line Items]
Shares sold (in shares) | shares	24.7
Per share purchase price (in dollars per share) | $ / shares	$ 30.42
Aggregate proceeds	$ 750
Percentage of outstanding common stock			5.60%
Scenario, Plan | Revision of Prior Period, Adjustment
Summary of Significant Accounting Policies [Line Items]
Income before income tax expense								$ (79)
Convex Group Limited
Summary of Significant Accounting Policies [Line Items]
Ownership (as a percent)		35.00%
Consideration for equity method ownership		$ 2,100
Intangible assets and other		450
Goodwill		$ 550
Convex Group Limited | Forecast
Summary of Significant Accounting Policies [Line Items]
Reinsurance percentage					12.50%	10.00%	7.50%
Onex Corporation
Summary of Significant Accounting Policies [Line Items]
Ownership (as a percent)		9.90%
Consideration for equity method ownership		$ 642