Derivatives and Hedge Accounting - Derivatives not designated as hedging instruments (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	$ (740)	$ (1,352)	$ (882)	$ (2,450)
AIG
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total		2		2
Net realized gains (losses) - excluding Fortitude Re funds withheld assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	119	(785)	(103)	(1,513)
Net realized gains (losses) on Fortitude Re funds withheld assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	(10)	(59)	13	(34)
Net realized losses on Fortitude Re funds withheld embedded derivatives
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	(316)	(251)	(302)	(847)
Income Statement Location [Axis]: us-gaap:InsuranceCommissionsAndFees
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	18	16	34	31
Income Statement Location [Axis]: us-gaap:MarketRiskBenefitChangeInFairValueGainLoss
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	(542)	(252)	(531)	(62)
Income Statement Location [Axis]: us-gaap:NetInvestmentIncome
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	(9)	(23)	7	(25)
Income Statement Location [Axis]: us-gaap:PolicyholderBenefitsAndClaimsIncurredNet
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	0	2	0	0
Interest rate contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	(25)	(48)	(149)	(70)
Foreign exchange contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	101	(397)	118	(616)
Equity contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	1,156	352	540	(102)
Credit contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	152	100	42	31
Other contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	15	16	38	32
Embedded derivatives
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	(1,823)	(1,124)	(1,169)	(878)
Embedded derivatives \| Net realized losses on Fortitude Re funds withheld embedded derivatives
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	$ (316)	$ (251)	$ (302)	$ (847)