Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income (Loss) Per Common Share
Net income (loss)	$ (8,386)	$ (15,211)	$ (27,496)	$ 3,949
Net income (loss) per common share:
Basic (in dollars per share)	$ (0.21)	$ (0.39)	$ (0.69)	$ 0.10
Diluted (in dollars per share)	$ (0.21)	$ (0.39)	$ (0.69)	$ 0.10
Basic weighted average shares outstanding	39,693	39,379	39,666	39,275
Effect of potentially dilutive share-based awards				786
Diluted weighted average shares outstanding	39,693	39,379	39,666	40,061