Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 2,591	$ 2,306	$ 2,587	$ 2,196
Ending Balance	2,732	2,396	2,732	2,396
Tax impact for the changes in each component of accumulated other comprehensive (loss) income
Net translation on investments in foreign operations	0	0	20	3
Net hedges of investments in foreign operations	(68)	12	41	(6)
Total tax impact	(68)	12	61	(3)
Foreign Currency Translation Adjustment Gains (Losses) [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(1,224)	(1,053)	(1,087)	(1,060)
Net translation losses of investments in foreign operations	275	(58)	(208)	6
Net gains (losses) related to hedges of investments in foreign operations	(216)	36	130	(21)
Net change in accumulated other comprehensive loss	59	(22)	(78)	(15)
Ending Balance	$ (1,165)	$ (1,075)	$ (1,165)	$ (1,075)