Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net income	$ 116	$ 46	$ 61	$ 36	$ 161	$ 97
Weighted Average Shares
Weighted average common shares outstanding (in shares)	56,790,642		56,446,077		56,723,254	56,670,690
Effect of dilutive securities
Stock-based awards (in shares)	333,064		615,745		433,561	651,823
Weighted average diluted common shares (in shares)	57,123,706		57,061,822		57,156,815	57,322,513
Earnings per common share
Basic earnings per common share (in dollars per share)	$ 2.04		$ 1.08		$ 2.85	$ 1.71
Effect of dilutive securities
Stock-based awards (in dollars per share)	(0.01)		(0.02)		(0.02)	(0.02)
Diluted earnings per common share (in dollars per share)	$ 2.03		$ 1.06		$ 2.83	$ 1.69