Investments (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Gain (Loss) on Securities [Line Items]
Investment and derivative, realized gain (loss), coinsurance agreement		$ 35,000,000
Debt securities, available-for-sale, realized loss	$ 49,000,000	134,000,000	$ 141,000,000	$ 222,000,000
Embedded derivative, gain on embedded derivative		24,000,000
Mortgage loan losses due to changes in expected credit losses	5,000,000	8,000,000	11,000,000	8,000,000
Commitments to purchase or fund privately placed debt securities	1,555,000,000		1,555,000,000
Commitments to sell various privately placed debt securities	65,000,000		65,000,000
Mortgage loans
Gain (Loss) on Securities [Line Items]
Financing receivable, accrued interest, after allowance for credit loss	4,000,000		4,000,000
Fixed maturity securities
Gain (Loss) on Securities [Line Items]
Debt securities, available-for-sale, accrued interest, after allowance for credit loss	$ 430,000,000	401,000,000	$ 430,000,000	$ 401,000,000	$ 394,000,000
Funds Withheld Liability Securities
Gain (Loss) on Securities [Line Items]
Debt securities, available-for-sale, realized loss		$ 59,000,000