Net (Loss) Income Per Share - Schedule of Calculation of Basic and Diluted Net (Loss) Income 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
Numerator:
Net (loss) income	$ (6.6)	$ 29.1	$ 19.2	$ 28.0	$ 22.5	$ 47.2
Denominator – Weighted-average common shares outstanding (in thousands):
Basic	15,781,000		16,063,000		15,809,000	16,085,000
Add: dilutive effect of non-vested common shares, restricted stock units and performance shares			177,000		120,000	213,000
Diluted	15,781,000		16,240,000		15,929,000	16,298,000
Net (loss) income per common share, Basic:	$ (0.41)		$ 1.19		$ 1.42	$ 2.93
Net (loss) income per common share, Diluted:	$ (0.41)		$ 1.18		$ 1.41	$ 2.89