CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 111	$ 265	$ 415
Other comprehensive income (loss)—net of tax
Foreign currency translation adjustment	(134)	106	(56)
Defined benefit plans	(22)	17	51
Other comprehensive income (loss), net of tax	(156)	123	(5)
Comprehensive income (loss)	(45)	388	410
Less: Comprehensive income (loss) attributable to noncontrolling interests	54	69	64
Comprehensive income (loss) attributable to common shareholders	$ (99)	$ 319	$ 346