CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 45	$ 63	$ (60)	$ 137
Other comprehensive income (loss) — net of tax
Foreign currency translation adjustment	(18)	(99)	17	(72)
Cash flow hedges	(3)	0	1	0
Defined benefit plans	(2)	4	(1)	7
Other comprehensive income (loss) — net of tax	(23)	(95)	17	(65)
Comprehensive income (loss)	22	(32)	(43)	72
Less: Comprehensive income (loss) attributable to noncontrolling interests	18	9	36	31
Comprehensive income (loss) attributable to common shareholders	$ 4	$ (41)	$ (79)	$ 41