Reinsurance - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Oct. 01, 2023 agreement
Ceded Credit Risk [Line Items]
Number of reinsurance recoverable agreements | agreement				2
Deposit assets, net of allowance for credit losses	$ 30,501	$ 30,501	$ 28,789
Investments	131,812	131,812	124,331
Fortitude Re
Ceded Credit Risk [Line Items]
Deposits assets	8,000	8,000	7,800
Investments	9,800	9,800	9,900
Fixed Annuities | Fortitude Re
Ceded Credit Risk [Line Items]
Reinsurance recoverables	10,700	10,700	10,500
Reinsurance recoverables on unpaid losses	2,600	2,600	2,700
Reinsurance recoverable amortization	23	67
Deposit assets, net of allowance for credit losses	$ 3,500	$ 3,500	$ 4,200