Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Basic earnings (loss) per share:
Net income (loss)	$ (16,013)	$ 398	$ (19,612)	$ 2,148
Weighted-average common shares	39,448	38,347	39,147	38,085
Basic earnings (loss) per share	$ (0.41)	$ 0.01	$ (0.50)	$ 0.06
Diluted earnings (loss) per share:
Net income (loss)	$ (16,013)	$ 398	$ (19,612)	$ 2,148
Weighted-average common shares	39,448	38,347	39,147	38,085
Incremental Common Shares Attributable To Stock Options And Restricted Stock Units		3,330		3,531
Incremental Common Shares Attributable To Contingently Issuable Shares		88		85
Weighted-average common shares and equivalents	39,448	41,765	39,147	41,701
Diluted earnings (loss) per share	$ (0.41)	$ 0.01	$ (0.50)	$ 0.05