Consolidated Statement of Comprehensive Income - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income		$ 2,420	$ 2,242	$ 2,593
Other comprehensive income (loss), net of related taxes:
Foreign currency translation, net of related taxes of ($40), $2 and ($8), respectively		488	(9)	(67)
Net unrealized gains (losses) on available-for-sale securities, net of reclassification adjustment and net of related taxes of $165, $212 and ($134), respectively		436	545	(302)
Net unrealized gains (losses) on available-for-sale securities designated in fair value hedges, net of related taxes of $1, $6 and $9, respectively		3	18	24
Non-credit impairment on held-to-maturity securities previously identified under ASC 320, net of related taxes of zero, $1 and $2, respectively (1)	[1]	0	1	4
Net unrealized gains (losses) on cash flow hedges, net of related taxes of $46, $9 and ($17), respectively		127	25	(33)
Net unrealized gains (losses) on retirement plans, net of related taxes of $3, ($8) and $8, respectively		9	(16)	27
Other comprehensive income (loss)		1,063	564	(347)
Total comprehensive income		$ 3,483	$ 2,806	$ 2,246

[1] We adopted ASU 2016-13, Financial Instruments - Credit Losses (ASC 326) : Measurement of Credit Losses on Financial Instruments, on January 1, 2020. Non-credit impairment on HTM securities was previously recognized under ASC 320. Please refer to Note 1 for additional information.