Investments (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Gain (Loss) on Securities [Line Items]
Mortgage loan losses due to changes in expected credit losses	$ 0	$ 13,000,000
Reduction of net unrealized gains on investments included in AOCI due to shadow adjustments	2,301,000,000		$ 2,773,000,000
Notional value	256,000,000		190,000,000
Derivative liability, fair value, gross liability	(2,000,000)		(19,000,000)
Commitments to purchase or fund privately placed debt securities	1,365,000,000
Commitments to sell various privately placed debt securities	100,000,000
Common Stock
Gain (Loss) on Securities [Line Items]
Equity securities, FV-NI, gain (loss)	13,000,000	(45,000,000)
Non-redeemable preferred stock
Gain (Loss) on Securities [Line Items]
Equity securities, FV-NI, gain (loss)	2,000,000	(133,000,000)
Fixed maturity securities
Gain (Loss) on Securities [Line Items]
Interest receivable	389,000,000	$ 390,000,000	$ 371,000,000
Mortgage loans
Gain (Loss) on Securities [Line Items]
Interest receivable	$ 4,000,000