Income Taxes - Schedule of Changes in Amount of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in the amount of unrecognized tax benefits
Beginning balance	$ 297	$ 285	$ 210
Additions based on tax positions related to the current year	6	3	42
Additions for tax positions of prior years	13	49	100
Reductions for tax positions of prior years	(14)	(31)	(24)
Settlements	(5)	(5)	(53)
Foreign currency translation			10
Foreign currency translation	(1)	(4)
Ending balance	$ 296	$ 297	$ 285