Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning Balance	$ 23,071	$ 22,290	$ 18,261
Net unrealized gains (losses)	32	41	(10)
Amounts reclassified into earnings	(3)
Net translation of investments in foreign operations	215	84	(500)
Net gains (losses) related to hedges of investment in foreign operations			328
Net gains (losses) related to hedges of investment in foreign operations	(252)	(140)
Pension and other postretirement benefits	(150)	(125)	11
Other			2
Net change in accumulated other comprehensive (loss) income	(158)	(140)	(169)
Ending Balance	22,984	23,071	22,290
Tax impact for the changes in each component of accumulated other comprehensive (loss) income
Net unrealized investment securities	9	12	(2)
Net translation on investments in foreign operations	17	24	(44)
Net hedges of investments in foreign operations	(79)	(43)
Net hedges of investments in foreign operations			107
Pension and other postretirement benefits	(28)	(38)	9
Total tax impact	(81)	(45)	70
Accumulated Other Comprehensive Loss [Member]
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning Balance	(2,737)	(2,597)	(2,428)
Ending Balance	(2,895)	(2,737)	(2,597)
Net Unrealized Investment Gains (Losses) on Investment Securities [Member]
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning Balance	33	(8)	0
Net unrealized gains (losses)	32	41	(10)
Amounts reclassified into earnings	0
Net translation of investments in foreign operations	0	0	0
Net gains (losses) related to hedges of investment in foreign operations			0
Net gains (losses) related to hedges of investment in foreign operations	0	0
Pension and other postretirement benefits	0	0	0
Other			2
Net change in accumulated other comprehensive (loss) income	32	41	(8)
Ending Balance	65	33	(8)
Foreign Currency Translation Adjustments [Member]
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning Balance	(2,189)	(2,133)	(1,961)
Net unrealized gains (losses)	0	0	0
Amounts reclassified into earnings	(3)
Net translation of investments in foreign operations	215	84	(500)
Net gains (losses) related to hedges of investment in foreign operations			328
Net gains (losses) related to hedges of investment in foreign operations	(252)	(140)
Pension and other postretirement benefits	0	0	0
Other			0
Net change in accumulated other comprehensive (loss) income	(40)	(56)	(172)
Ending Balance	(2,229)	(2,189)	(2,133)
Net Unrealized Pension and Other Postretirement Benefit (Losses) Gains [Member]
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning Balance	(581)	(456)	(467)
Net unrealized gains (losses)	0	0	0
Amounts reclassified into earnings	0
Net translation of investments in foreign operations	0	0	0
Net gains (losses) related to hedges of investment in foreign operations			0
Net gains (losses) related to hedges of investment in foreign operations	0	0
Pension and other postretirement benefits	(150)	(125)	11
Other			0
Net change in accumulated other comprehensive (loss) income	(150)	(125)	11
Ending Balance	$ (731)	$ (581)	$ (456)