Earnings Per Share - Schedule of Reconciliation of Numerators and Denominators Used to Calculate Basic EPS and Diluted EPS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income	$ 149	$ 167	$ 497	$ 492
Weighted average shares of common stock outstanding	120	130	123	135
Dilutive effect of stock-based awards	1	1	1	0
Diluted weighted average shares of common stock outstanding	121	131	124	135
Basic earnings per share attributable to common stockholders (USD per share)	$ 1.24	$ 1.28	$ 4.04	$ 3.66
Diluted earnings per share attributable to common stockholders (USD per share)	$ 1.23	$ 1.27	$ 4.01	$ 3.64