Consolidated Statement of Comprehensive Income Statement - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net Income (Loss) Attributable to Parent	$ 1,067	$ 1,289	$ 1,150
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Abstract]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	33	(39)	415
Other Comprehensive Income (Loss), Reclassification Adjustment to Net Income for Sale of Securities, Net of Tax	147	99	167
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	(114)	(138)	248
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	3	(26)	(17)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	(1)	(22)	(20)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	4	(48)	(37)
Other Comprehensive Income Unrealized Gain (Loss) on Net Investment Hedges Arising During the Period Net of Tax	1	18	8
Other Comprehensive Income (Loss), Reclassification Adjustment for Net Investment Hedges Included in Net Income, Discontinued Operation, Net of Tax	0	(3)	0
Other Comprehensive Income (Loss), Net Investment Hedges Attributable to Parent, Net of Tax	1	21	8
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustments and Net Investment Hedges, Net of Tax	5	(27)	(29)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	0	1	2
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	(3)	0	(15)
Other Comprehensive Income (Loss), Reclassification Adjustment to Net Income, Pension and Other Postretirement Benefit Plans, for Net (Gain) Loss, Net of Tax	(2)	1	(4)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	(1)	(1)	(11)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(110)	(165)	210
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	957	1,124	1,360
Retained Earnings [Member]
Net Income (Loss) Attributable to Parent	$ 1,067	$ 1,289	$ 1,150