Earnings Per Share, Calculation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator:
Net loss	$ 22.1	$ 15.9	$ (249.9)	$ 56.2
Denominator — Weighted-average common shares outstanding (in thousands):
Basic	17,123	17,707	17,178	17,853
Add: dilutive effect of non-vested common shares, restricted stock units and performance shares	305	134	0	143
Add: dilutive effect of warrants	744	778	0	596
Diluted	18,172	18,619	17,178	18,592
Net income (loss) per common share:
Basic	$ 1.29	$ 0.90	$ (14.55)	$ 3.15
Earnings per common share, Diluted:
Diluted	$ 1.21	$ 0.85	$ (14.55)	$ 3.02