Investments (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Gain (Loss) on Securities [Line Items]
Non-income producing fixed maturity securities	$ 1,000,000	$ 0
Investments that exceed ten percent of stockholders' equity	0	0
Gross gains	42,000,000	48,000,000	$ 75,000,000
Debt securities, available-for-sale, realized loss	125,000,000	150,000,000	166,000,000
Mortgage loan losses due to changes in expected credit losses	5,000,000	0	11,000,000
Limited partnership investments	2,772,000,000	2,520,000,000
Undistributed earnings of limited partnership investments	$ 379,000,000	$ 334,000,000
Percentage of limited partnerships reported on a current basis	12.00%
Percentage of limited partnerships reported on a one month lag	2.00%
Limited partnerships invested in private debt and equity	88.00%	86.00%
Percentage of limited partnerships employing hedge fund strategies focused on fixed income and equity investments	12.00%	14.00%
Carrying value of ten largest limited partnerships	$ 630,000,000	$ 648,000,000
Carrying value of limited partnerships as percentage of aggregate partnership equity	1.00%	1.00%
Income as percentage of change in partnership equity for all limited partnerships	1.00%
Obligation to return cash	$ 0
Derivative liability, subject to master netting arrangement, collateral, right to reclaim cash offset	0
Commitments to purchase or fund privately placed debt securities	1,770,000,000
Commitments to sell various privately placed debt securities	45,000,000
Carrying value of securities deposited under requirements of regulatory authorities	3,400,000,000	$ 3,100,000,000
Cash and securities deposited as collateral for letters of credit	600,000,000	700,000,000
Fixed maturity securities
Gain (Loss) on Securities [Line Items]
OCI, debt securities, available-for-sale, gain (loss), after adjustment, before tax	1,128,000,000	(352,000,000)	1,431,000,000
Debt securities, available-for-sale, accrued interest, after allowance for credit loss	470,000,000	442,000,000
Mortgage loans
Gain (Loss) on Securities [Line Items]
Financing receivable, accrued interest, after allowance for credit loss	5,000,000
Financing receivable, allowance for credit loss	15,000,000	35,000,000	$ 35,000,000
Amortized cost of nonaccrual loans	30,000,000	48,000,000
Nonaccruing loans, interest income	1,000,000
Financing receivable, still accruing	15,000,000
Non-income producing mortgage loans	$ 15,000,000
Allowance for credit loss on non-income producing loans		$ 14,000,000