Reinsurance - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Ceded Credit Risk [Line Items]
Other investments	$ 4,988	$ 4,757
Deposit assets, net of allowance for credit losses	21,084	21,056
LNBAR
Ceded Credit Risk [Line Items]
Reinsurance recoverables	14,000	13,200
Reinsurance recoverables on unpaid losses	4,200	4,200
Reinsurance recoverable for unpaid claims and claims adjustments	43
Other investments	1,000	871
Trust funded to support reinsurance receivable	12,600	13,000
Fortitude Re | Fixed Annuities
Ceded Credit Risk [Line Items]
Reinsurance recoverables	10,500	10,500
Reinsurance recoverables on unpaid losses	2,700	2,700
Reinsurance recoverable for unpaid claims and claims adjustments	22
Deposit assets, net of allowance for credit losses	$ 3,900	$ 4,200