Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	$ (1,012)	$ (831)	$ (845)	$ (925)
Other comprehensive income (loss) before reclassifications	96	(92)	(52)	(81)
Amounts reclassified from accumulated other comprehensive (income) loss	57	(73)	38	(87)
Adjustment to adopt reclassification of certain tax effects from AOCI				97
Other comprehensive income (loss)	153	(165)	(14)	(71)
Balance at end of period	(859)	(996)	(859)	(996)
Foreign currency translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(957)	(758)	(777)	(889)
Other comprehensive income (loss) before reclassifications	145	(160)	(35)	(127)
Amounts reclassified from accumulated other comprehensive (income) loss	0	0	0	0
Adjustment to adopt reclassification of certain tax effects from AOCI				98
Other comprehensive income (loss)	145	(160)	(35)	(29)
Balance at end of period	(812)	(918)	(812)	(918)
Derivative financial instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(55)	(73)	(68)	(36)
Other comprehensive income (loss) before reclassifications	(49)	68	(17)	46
Amounts reclassified from accumulated other comprehensive (income) loss	57	(73)	38	(87)
Adjustment to adopt reclassification of certain tax effects from AOCI				(1)
Other comprehensive income (loss)	8	(5)	21	(42)
Balance at end of period	$ (47)	$ (78)	$ (47)	$ (78)