Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jan. 31, 2016
Common stock repurchased and retired (in shares)	511,744		831,744
Common stock repurchased and retired	$ 12,400		$ 20,000
Average share price (in dollars per share)	$ 24.30		$ 24.05
Change in Stockholders’ Equity
Decrease in total stockholders' equity			$ 16,100
Decrease in stockholders' equity due to net loss	$ 596	$ (33,258)	8,123	$ (46,162)
Increase in stockholders' equity from the exercise of stock options			800
Increase in stockholders' equity from the issuance of common stock under ESPP			800
Increase in stockholders' equity related to equity-based compensation expense			$ 11,300
Maximum
Share repurchase program, authorized amount					$ 60,000