Net Income (Loss) Per Share - Computation Earnings Per Share, Basic and Diluted (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Earnings Per Share [Abstract]        
Net (loss) income $ (8,349) $ (13,805) $ 4,209 $ (34,962)
Weighted average common shares outstanding - basic 20,236 20,021 20,279 19,879
Dilutive effect of common stock equivalents     232  
Weighted average common shares outstanding - diluted 20,236 20,021 20,511 19,879
Net (loss) income per share        
Basic $ (0.41) $ (0.69) $ 0.21 $ (1.76)
Diluted $ (0.41) $ (0.69) $ 0.21 $ (1.76)