Investments (Realized Gain (Loss) Related To Certain Investments) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Realized gain (loss) related to certain investments
Gain (loss) on other investments	[1]	$ 2	$ (3)
Associated amortization of DAC, VOBA, DSI and DFEL and changes in other contract holder funds		(5)	(7)
Total realized gain (loss) related to certain investments, pre-tax	[2]	(21)	(13)
Fixed maturity AFS securities [Member]
Realized gain (loss) related to certain investments
AFS securities. Gross gains	[3]	14	8
AFS securities. Gross losses	[3]	(32)	(12)
Equity AFS Securities [Member]
Realized gain (loss) related to certain investments
AFS securities. Gross gains			1
AFS securities. Gross losses
Equity Securities [Member] | Maximum [Member]
Realized gain (loss) related to certain investments
Gain (loss) on other investments		$ 1

[1] Includes market adjustments on equity securities still held as of March 31, 2018 of less than $1 million.

[2] See "Realized Gain (Loss) Related to Certain Investments" section in Note 5.

[3] These amounts are represented net of related fair value hedging activity. See Note 6 for more information.