Earnings Per Share - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Numerator:
Net income (loss)	$ (39,891)	$ 4,983	$ 1,431	$ 1,139	$ 37,454	$ 5,114	$ 1,605	$ 289	$ (32,338)	$ 44,462	$ (8,660)
Denominator:
Denominator for basic earnings per share—weighted-average shares outstanding (in shares)									52,791	52,096	50,875
Effect of dilutive securities:
Employee stock options and restricted common shares (in shares)									0	924	0
Contingently issuable shares (in shares)									0	84	0
Denominator for dilutive earnings per share (in shares)									52,791	53,104	50,875
Basic earnings (loss) per share (in USD per share)	$ (0.75)	$ 0.09	$ 0.03	$ 0.02	$ 0.71	$ 0.10	$ 0.03	$ 0.01	$ (0.61)	$ 0.85	$ (0.17)
Diluted earnings (loss) per share (in USD per share)	$ (0.75)	$ 0.09	$ 0.03	$ 0.02	$ 0.69	$ 0.10	$ 0.03	$ 0.01	$ (0.61)	$ 0.84	$ (0.17)