Derivatives and Hedging Activities (Income Statement) (Details 2) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 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	$ 17	$ 3
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	17	1
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		2
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
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	1	(1)
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
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	(3)	16
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	(3)	15
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
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	28	12
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	36	(7)
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	(8)	19
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	(79)	(149)
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	280	426
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	(398)	(81)
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	25	(462)
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	12	(8)
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	2	(24)
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)	4
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
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	$ (2)	$ 1