Stockholders' Equity - Schedule of Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Equity [Abstract]
Net unrealized gains on cash flow hedges	$ 293	$ 276	$ 161
Net unrealized gains (losses) on available-for-sale securities portfolio	9	273	(56)
Net unrealized gains (losses) related to reclassified available-for-sale securities	(28)	39	(72)
Net unrealized gains (losses) on available-for-sale securities	(19)	312	(128)
Net unrealized losses on available-for-sale securities designated in fair value hedges	(109)	(121)	(97)
Other-than-temporary impairment on available-for-sale securities related to factors other than credit	0	1	4
Net unrealized losses on hedges of net investments in non-U.S. subsidiaries	(14)	(14)	(14)
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit	(16)	(29)	(47)
Net unrealized losses on retirement plans	(183)	(272)	(203)
Foreign currency translation	(1,394)	(660)	229
Total	$ (1,442)	$ (507)	$ (95)