Investments - Credit Loss Expense Incurred (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	$ (12)	$ (17)	$ (14)	$ (33)
Location, Statement of Income, Balance [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(32)	(19)	(57)	(47)
Corporate bonds
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(9)	(17)	(11)	(25)
Corporate bonds \| Location, Statement of Income, Balance [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(11)	(21)	(20)	(30)
RMBS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	0	0	0	0
RMBS \| Location, Statement of Income, Balance [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	0	1	0	2
CMBS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(3)	0	(3)	0
CMBS \| Location, Statement of Income, Balance [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	(3)	0	(3)	0
ABS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	0	0	0	(8)
ABS \| Location, Statement of Income, Balance [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)	$ (18)	$ 1	$ (34)	$ (19)