Investments (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Gain (Loss) on Securities [Line Items]
Reduction of net unrealized gains on investments included in AOCI due to shadow adjustments	$ 1,700,000,000		$ 2,198,000,000
Notional value	196,000,000		182,000,000
Derivative liability, fair value, gross liability	(1,000,000)		$ (7,000,000)
Commitments to purchase or fund privately placed debt securities	1,025,000,000
Commitments to sell various privately placed debt securities	85,000,000
Common Stock
Gain (Loss) on Securities [Line Items]
Equity securities, FV-NI, gain (loss)	(45,000,000)	$ 17,000,000
Trading portfolio
Gain (Loss) on Securities [Line Items]
Equity securities, FV-NI, gain (loss)	(2,000,000)	1,000,000
Preferred stock
Gain (Loss) on Securities [Line Items]
Equity securities, FV-NI, gain (loss)	(133,000,000)	$ 42,000,000
Fixed maturity securities
Gain (Loss) on Securities [Line Items]
Interest Receivable	390,000,000
Mortgage loans
Gain (Loss) on Securities [Line Items]
Interest Receivable	4,000,000
Debt securities, available-for-sale, allowance for credit loss, period increase (decrease)	13,000,000
Financing receivable, allowance for credit loss, writeoff	$ 0