CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (1,460)	$ (220)	$ 111
Other comprehensive income (loss)—net of tax
Foreign currency translation adjustments	(12)	16	(134)
Cash flow hedges	4	0	0
Defined benefit plans	(11)	(45)	(22)
Other comprehensive income (loss), net of tax	(19)	(29)	(156)
Comprehensive income (loss)	(1,479)	(249)	(45)
Less: Comprehensive income (loss) attributable to noncontrolling interests	75	104	54
Comprehensive income (loss) attributable to common shareholders	$ (1,554)	$ (353)	$ (99)