Derivatives and Hedge Accounting - Derivatives not designated as hedging instruments (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	$ 1,468	$ (1,209)	$ 586	$ (3,659)
AIG
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total		1		3
Net realized gains (losses) - excluding Fortitude Re funds withheld assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	902	(126)	799	(1,639)
Net realized losses on Fortitude Re funds withheld assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	(183)	(5)	(170)	(39)
Net realized gains (losses) on Fortitude Re funds withheld embedded derivatives
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	1,032	(670)	730	(1,517)
Income Statement Location [Axis]: us-gaap:InsuranceCommissionsAndFees
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	15	16	49	47
Income Statement Location [Axis]: us-gaap:MarketRiskBenefitChangeInFairValueGainLoss
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	(282)	(431)	(813)	(493)
Income Statement Location [Axis]: us-gaap:NetInvestmentIncome
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	(10)	7	(3)	(18)
Income Statement Location [Axis]: us-gaap:PolicyholderBenefitsAndClaimsIncurredNet
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	(6)	0	(6)	0
Interest rate contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	(656)	35	(805)	(35)
Foreign exchange contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	67	(30)	185	(646)
Equity contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	171	367	711	265
Credit contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	30	27	72	58
Other contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	21	17	59	49
Embedded derivatives
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	803	(955)	(366)	(1,833)
Embedded derivatives \| Net realized gains (losses) on Fortitude Re funds withheld embedded derivatives
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	$ 1,032	$ (670)	$ 730	$ (1,517)