Investments - Credit Loss Expense Incurred (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	$ (14)	$ (7)	$ (43)	$ (23)
Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(18)	(14)	(65)	(40)
Corporate bonds
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(14)	(6)	(31)	(8)
Corporate bonds | Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(19)	(9)	(48)	(20)
RMBS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	0	0	0	0
RMBS | Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(1)	(1)	1	(1)
ABS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	0	(1)	(12)	(15)
ABS | Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	$ 2	$ (4)	$ (18)	$ (19)