Earnings (Loss) per Common Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings (Loss) per Common Share
Net income	$ 0.1	$ 8.4
Basic weighted-average shares	81,037,633	80,348,870
Effect of dilutive securities:
Restricted stock awards	499,180	562,530
Diluted weighted-average shares	81,536,813	80,911,400
Basic net income (loss) per share (in dollars per share)	$ 0.00	$ 0.10
Diluted net income (loss) per share (in dollars per share)	$ 0.00	$ 0.10