Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 685	$ 563	$ 1,807	$ 1,550
Other comprehensive income (loss), net of related taxes:
Foreign currency translation, net of related taxes of ($7) and ($14), respectively	259	38	785	132
Net unrealized gains (losses) on available-for-sale securities, net of reclassification adjustment and net of related taxes of $28 and ($11), respectively	47	(13)	519	533
Net unrealized gains (losses) on available-for-sale securities designated in fair value hedges, net of related taxes of $4 and $9, respectively	4	13	13	(9)
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, net of related taxes of $1 and $1, respectively	1	2	3	5
Net unrealized gains (losses) on cash flow hedges, net of related taxes of ($15) and ($27), respectively	(27)	(39)	(274)	(213)
Net unrealized gains (losses) on retirement plans, net of related taxes of $0 and ($1), respectively	2	3	10	1
Other comprehensive income (loss)	286	4	1,056	449
Total comprehensive income	$ 971	$ 567	$ 2,863	$ 1,999