UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net loss	$ (55)	$ (699)
Other comprehensive loss, net of tax
Foreign currency translation adjustments	(30)	(77)
Unrealized losses on cash flow hedges	(11)	0
Net unrealized losses on available-for-sale securities	(1)	(74)
Total other comprehensive loss, net of tax	(42)	(151)
Comprehensive loss	$ (97)	$ (850)