Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 2,143	$ 1,980	$ 2,022
Other comprehensive income (loss), net of related taxes:
Foreign currency translation, net of related taxes of ($11), ($101) and ($94), respectively	(372)	(735)	(889)
Net unrealized gains (losses) on available-for-sale securities, net of reclassification adjustment and net of related taxes of ($119), ($195) and $269, respectively	(181)	(331)	437
Net unrealized gains (losses) on available-for-sale securities designated in fair value hedges, net of related taxes of $16, $5 and ($15), respectively	23	12	(24)
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, net of related taxes of $5, $8 and $12, respectively	7	13	18
Net unrealized gains (losses) on cash flow hedges, net of related taxes of ($42), $24 and $74, respectively	(64)	17	115
Net unrealized gains (losses) on retirement plans, net of related taxes of $1, $51 and ($50), respectively	(11)	89	(69)
Other comprehensive income (loss)	(598)	(935)	(412)
Total comprehensive income	$ 1,545	$ 1,045	$ 1,610