Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Basic and Diluted Earnings per Share [Line Items]
Net income (loss) from continuing operations	$ (19,082)	$ 11,628	$ (389)	$ 37,083
Weighted-average common shares outstanding (in shares)	24,960,086	25,389,633	25,177,133	25,322,427
Weighted-average common shares for EPS calculation (in shares)	24,960,086	25,815,346	25,666,405	25,711,014
Earnings (loss) per common share from continuing operations, basic (in dollars per share)	$ (0.77)	$ 0.46	$ (0.01)	$ 1.47
Earnings (loss) per common share from continuing operations, diluted (in dollars per share)	(0.77)	0.45	(0.01)	1.44
Earnings per common share from discontinued operations, basic (in dollars per share)	0.05	0.03	0.21	0.03
Earnings per common share from discontinued operations, diluted (in dollars per share)	0.05	0.03	0.21	0.03
Earnings (loss) per common share, basic (in dollars per share)	(0.72)	0.49	0.20	1.50
Earnings (loss) per common share, diluted (in dollars per share)	$ (0.72)	$ 0.48	$ 0.20	$ 1.47
Awards excluded from diluted earnings per share calculation (in shares)	0	0	0	0
Restricted Stock Unit Awards
Basic and Diluted Earnings per Share [Line Items]
Add dilutive effect of share-based awards outstanding (in shares)	0	155,270	253,082	155,270
Stock Options
Basic and Diluted Earnings per Share [Line Items]
Add dilutive effect of share-based awards outstanding (in shares)	0	270,443	236,190	233,317