Shareholders' Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	$ 11,659	$ 10,294	$ 8,693
Balance at end of period	12,726	11,659	10,294
AOCI Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(1,066)	(768)	(1,238)
Balance at end of period	(1,119)	(1,066)	(768)
Unrealized (Loss) Gain on Hedges [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	9	16	17
Other comprehensive (loss) income, net of tax	(58)	(7)	(1)
Balance at end of period	(49)	9	16
Defined Benefit Plans [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	1	1	(20)
Reclassification adjustment	0	0	21
Balance at end of period	1	1	1
Foreign Currency Translation Adjustment [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(1,076)	(785)	(1,235)
Other comprehensive (loss) income, net of tax	5	(291)	253
Reclassification adjustment	0	0	197
Balance at end of period	$ (1,071)	$ (1,076)	$ (785)