Consolidated Statements of Comprehensive Income Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net Income (Loss) Attributable to Parent	$ 447	$ 429
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	279	86
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	150	44
Credit Risk Adjustment	(2)	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	59	(73)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	486	57
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 933	$ 486