Investments (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Gain (Loss) on Securities [Line Items]
Non-income producing fixed maturity securities	$ 1,000,000	$ 1,000,000
Investments that exceed ten percent of stockholders' equity	0	0
Mortgage loan losses due to changes in expected credit losses	(10,000,000)	21,000,000	$ 0
Limited partnership investments	1,859,000,000	1,619,000,000
Undistributed earnings of limited partnership investments	$ 266,000,000	$ 235,000,000
Percentage of limited partnerships reported on a current basis	32.00%
Percentage of limited partnerships reported on a one month lag	6.00%
Percentage of limited partnerships employing hedge fund strategies focused on fixed income and equity investments	32.00%	51.00%
Limited partnerships invested in private debt and equity	68.00%	49.00%
Carrying value of ten largest limited partnerships	$ 665,000,000	$ 775,000,000
Carrying value of limited partnerships as percentage of aggregate partnership equity	1.00%	2.00%
Income as percentage of change in partnership equity for all limited partnerships	2.00%	2.00%	2.00%
Obligation to return cash	$ 0	$ 0
Notional value	270,000,000	190,000,000
Derivative liability, fair value, gross liability	(12,000,000)	(19,000,000)
Commitments to purchase or fund privately placed debt securities	1,230,000,000
Commitments to sell various privately placed debt securities	90,000,000
Carrying value of securities deposited under requirements of regulatory authorities	3,000,000,000	3,000,000,000
Cash and securities deposited as collateral for letters of credit	1,200,000,000	1,100,000,000
Non-Income Producing Mortgage Loans	7,000,000	0
5.875% face amount of $500, due August 15, 2020 | Senior Notes
Gain (Loss) on Securities [Line Items]
Realized investment gains (losses)		(20,000,000)	$ 21,000,000
Face amount		400,000,000	500,000,000
Common Stock
Gain (Loss) on Securities [Line Items]
Equity securities, FV-NI, gain (loss)	28,000,000	34,000,000
Non-redeemable preferred stock
Gain (Loss) on Securities [Line Items]
Equity securities, FV-NI, gain (loss)	2,000,000	(3,000,000)
Fixed maturity securities
Gain (Loss) on Securities [Line Items]
Debt securities, available-for-sale, accrued interest, after allowance for credit loss	369,000,000	371,000,000
OCI, debt securities, available-for-sale, gain (loss), after adjustment, before tax	(1,272,000,000)	$ 1,637,000,000	$ 2,620,000,000
Mortgage loans
Gain (Loss) on Securities [Line Items]
Financing receivable, accrued interest, after allowance for credit loss	$ 3,000,000