Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 587	$ 733	$ 1,095	$ 1,392
Other comprehensive income (loss), net of related taxes:
Foreign currency translation, net of related taxes of $7 and ($62), respectively	42	(338)	16	(187)
Net unrealized gains (losses) on available-for-sale securities, net of reclassification adjustment and net of related taxes of $210 and ($122), respectively	257	(122)	529	(271)
Net unrealized gains (losses) on available-for-sale securities designated in fair value hedges, net of related taxes of $1 and $8, respectively	5	5	3	23
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, net of related taxes of $1 and $3, respectively	1	(1)	1	(1)
Net unrealized gains (losses) on cash flow hedges, net of related taxes of $9 and ($10), respectively	1	40	25	(57)
Net unrealized gains (losses) on retirement plans, net of related taxes of ($4) and $3, respectively	0	2	(8)	14
Other comprehensive income (loss)	306	(414)	566	(479)
Total comprehensive income	$ 893	$ 319	$ 1,661	$ 913