Shareholders' Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	$ 11,316	$ 11,984	$ 12,726	$ 11,659
Balance at end of period	11,053	12,385	11,053	12,385
AOCI Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(1,662)	(1,024)	(1,119)	(1,066)
Balance at end of period	(1,663)	(1,034)	(1,663)	(1,034)
Unrealized (Loss) Gain on Hedges [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(166)	(6)	(49)	9
Other comprehensive (loss) income, net of tax	(34)	(18)	(151)	(33)
Balance at end of period	(200)	(24)	(200)	(24)
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	(1,497)	(1,019)	(1,071)	(1,076)
Other comprehensive (loss) income, net of tax	33	8	(393)	65
Balance at end of period	$ (1,464)	$ (1,011)	$ (1,464)	$ (1,011)