Investments - Credit Loss Expense Incurred (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	$ (17)	$ (16)	$ (33)	$ (17)
Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(19)	(23)	(47)	(25)
Corporate bonds
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(17)	(1)	(25)	(2)
Corporate bonds | Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(21)	(8)	(30)	(10)
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	0	2	0
ABS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	0	(15)	(8)	(15)
ABS | Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	$ 1	$ (15)	$ (19)	$ (15)