Derivatives and Hedging Activities (Income Statement) (Details 2) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net investment income [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	$ 6	$ (11)	$ 28	$ (15)
Net investment income [Member] | Derivatives not designated as hedging instruments [Member] | Interest rate contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	6	(1)	28	(8)
Net investment income [Member] | Derivatives not designated as hedging instruments [Member] | Equity contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	(1)	(10)	(1)	(7)
Net investment income [Member] | Derivatives not designated as hedging instruments [Member] | Foreign exchange contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	1		1
Banking and deposit interest expense [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	(1)	0	0	0
Banking and deposit interest expense [Member] | SMC embedded derivatives [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	(2)	(1)	(2)	(3)
Banking and deposit interest expense [Member] | Derivatives not designated as hedging instruments [Member] | Equity contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	1	1	2	3
Distribution expenses [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	17	14	22	39
Distribution expenses [Member] | Derivatives not designated as hedging instruments [Member] | Equity contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	17	13	22	36
Distribution expenses [Member] | Derivatives not designated as hedging instruments [Member] | Foreign exchange contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income		1		3
Interest credited to fixed accounts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	(6)	(6)	19	7
Interest credited to fixed accounts [Member] | IUL embedded derivatives [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	(40)	(24)	(18)	(43)
Interest credited to fixed accounts [Member] | Derivatives not designated as hedging instruments [Member] | Equity contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	34	18	37	50
Benefits, claims, losses and settlement expenses [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	(171)	(24)	(425)	(341)
Benefits, claims, losses and settlement expenses [Member] | GMWB and GMAB embedded derivatives [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	261	227	637	569
Benefits, claims, losses and settlement expenses [Member] | Derivatives not designated as hedging instruments [Member] | Interest rate contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	(205)	14	(738)	61
Benefits, claims, losses and settlement expenses [Member] | Derivatives not designated as hedging instruments [Member] | Equity contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	(229)	(261)	(341)	(920)
Benefits, claims, losses and settlement expenses [Member] | Derivatives not designated as hedging instruments [Member] | Credit contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	4	(3)	22	(22)
Benefits, claims, losses and settlement expenses [Member] | Derivatives not designated as hedging instruments [Member] | Foreign exchange contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income		1	(1)	(27)
Benefits, claims, losses and settlement expenses [Member] | Derivatives not designated as hedging instruments [Member] | Other contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	(2)	(2)	(4)	(2)
General and administrative expense [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	(2)	3	(8)	12
General and administrative expense [Member] | Derivatives not designated as hedging instruments [Member] | Equity contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	3	2	5	7
General and administrative expense [Member] | Derivatives not designated as hedging instruments [Member] | Foreign exchange contracts [Member]
Impact of derivatives not designated as hedging instruments on Consolidated Statements of Income
Amount of gain (loss) on derivatives recognized in income	$ (5)	$ 1	$ (13)	$ 5