Net Income Per Share - Computation of Basic and Dilutive Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income	$ 5,481	$ 3,321	$ 1,975	$ 1,197	$ 13,378	$ 6,551	$ 5,430	$ 4,087	$ 11,974	$ 29,446	$ 6,220
Denominator for basic earnings per share - weighted average shares (in shares)									105,928,348	105,929,205	105,793,008
Effect of dilutive securities: Stock options, warrants, and restricted stock (in shares)									6,513,361	7,699,277	7,502,496
Denominator for diluted earnings per share - weighted average shares adjusted for dilutive securities (in shares)									112,441,709	113,628,482	113,295,504
Income per common share - basic (in dollars per share)	$ 0.05	$ 0.03	$ 0.02	$ 0.01	$ 0.13	$ 0.06	$ 0.05	$ 0.04	$ 0.11	$ 0.28	$ 0.06
Income per common share - diluted (in dollars per share)	$ 0.05	$ 0.03	$ 0.02	$ 0.01	$ 0.11	$ 0.06	$ 0.05	$ 0.04	$ 0.11	$ 0.26	$ 0.05