Shareholders' Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	$ 11,053	$ 12,385	$ 12,726	$ 11,659
Balance at end of period	12,547	12,688	12,547	12,688
AOCI Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(1,663)	(1,034)	(1,119)	(1,066)
Balance at end of period	(1,564)	(1,210)	(1,564)	(1,210)
Unrealized (Loss) Gain on Hedges [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(200)	(24)	(49)	9
Other comprehensive (loss) income, net of tax	17	(12)	(134)	(45)
Balance at end of period	(183)	(36)	(183)	(36)
Defined Benefit Plans [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	1	1	1	1
Other comprehensive (loss) income, net of tax	0	0	0	0
Balance at end of period	1	1	1	1
Foreign Currency Translation Adjustment [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(1,464)	(1,011)	(1,071)	(1,076)
Other comprehensive (loss) income, net of tax	82	(164)	(311)	(99)
Balance at end of period	$ (1,382)	$ (1,175)	$ (1,382)	$ (1,175)