Reinsurance - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)	Oct. 01, 2023 agreement
Ceded Credit Risk [Line Items]
Number of reinsurance recoverable agreements | agreement						2
Investments	$ 131,144		$ 131,144		$ 129,254
Fortitude Re
Ceded Credit Risk [Line Items]
Deposits assets	8,300		8,300		8,100
Investments	9,100		9,100		9,300
Fixed Annuities | Fortitude Re
Ceded Credit Risk [Line Items]
Reinsurance recoverables	10,600		10,600		10,600
Reinsurance recoverables on unpaid losses	2,500		2,500		2,600
Reinsurance recoverable amortization	23	$ 22	46	$ 44
Deposits assets	$ 2,600		$ 2,600		$ 3,000