Earnings Per Share - Reconciliation of the Numerators and Denominators of the Earnings Per Share Calculations (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Net income attributable to the parent company	$ 124	$ 71	$ 232	$ 146
Less: Redeemable noncontrolling interests adjustment to redemption value	0	(2)	0	(2)
Net income available to common stockholders - Numerator diluted	124	69	232	144
Net income available to common stockholders - Numerator basic	$ 124	$ 69	$ 232	$ 144
Weighted-average shares outstanding - Basic	145.1	144.8	145.3	144.7
Employee compensation-related shares, including stock options	1.4	1.4	1.7	1.4
Weighted-average shares outstanding - Diluted	146.5	146.2	147.0	146.1