Accumulated Other Comprehensive Income (Loss) Before and After Tax (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, [Abstract]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	$ (191)	$ 185	$ (53)	$ 373
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, before Tax	45	41	100	84
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, Portion Attributable to Parent	(236)	144	(153)	289
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax [Abstract]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	71	(43)	20	(94)
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Tax	(16)	(1)	(36)	(7)
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax, Portion Attributable to Parent	87	(42)	56	(87)
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	(120)	142	(33)	279
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax	29	40	64	77
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	(149)	102	(97)	202
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	4	12	(16)	(10)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized upon Sale or Liquidation, before Tax	1	23	43	23
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent	3	(11)	(59)	(33)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	(1)	(3)	6	4
Other Comprehensive Income (Loss), Foreign Currency Translation Reclassification Adjustment Realized upon Sale or Liquidation, Tax	0	(3)	(20)	(3)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Parent	(1)	0	26	7
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	9	(10)	(6)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized upon Sale or Liquidation, Net of Tax	1	20	23	20
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	2	(11)	(33)	(26)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax [Abstract]
Other Comprehensive Income Unrealized Gain Loss On Net Investment Hedges Arising During the Period, Before Tax	(2)	(9)	16	2
Other Comprehensive Income (Loss), Reclassification Adjustment for Net Investment Hedges Included in Net Income, Discontinued Operation, before Tax			(4)
Other Comprehensive Income (Loss), Net Investment Hedges Attributable to Parent, before Tax			20
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Effect [Abstract]
Other Comprehensive Income Unrealized Gain Loss On Net Investment Hedges Arising During the Period, Tax	1	3	(6)	(1)
Other Comprehensive Income (Loss), Reclassification Adjustment for Net Investment Hedges Included in Net Income, Discontinued Operation, Tax			1
Other Comprehensive Income (Loss), Net Investment Hedges Attributable to Parent, Tax			(7)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Other Comprehensive Income Unrealized Gain Loss On Net Investment Hedges Arising During the Period Net of Tax	(1)	(6)	10	1
Other Comprehensive Income (Loss), Reclassification Adjustment for Net Investment Hedges Included in Net Income, Discontinued Operation, Net of Tax			(3)
Other Comprehensive Income (Loss), Net Investment Hedges Attributable to Parent, Net of Tax			13
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, [Abstract]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax		(7)		(7)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax [Abstract]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Tax		3		3
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Net of Tax		(4)		(4)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(235)	131	(192)	265
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	87	(42)	75	(84)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ (148)	$ 89	$ (117)	$ 181