Earnings per Share - Computation of EPS (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Weighted-average number of common shares outstanding-basic	82.8	89.9	83.1	73.7
Add: Effect of dilutive share-based compensation awards	0.0	0.0	0.1	0.0
Weighted-average number of shares-diluted	82.8	89.9	83.2	73.7