THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Numerator:
Net income (loss) to common stockholders	$ (6,754)	$ (4,582)	$ 9,195	$ (5,744)
Denominator:
Weighted-average common shares outstanding, basic (in shares)	23,257,492	22,764,322	23,195,775	22,736,505
Weighted-average common shares outstanding, diluted (in shares)	23,257,492	22,764,322	24,233,724	22,736,505
Basic (in dollars per share)	$ (0.29)	$ (0.20)	$ 0.40	$ (0.25)
Diluted (in dollars per share)	$ (0.29)	$ (0.20)	$ 0.38	$ (0.25)
Restricted Stock Units
Schedule of Earnings per Share [Line Items]
Incremental shares attributable to share-based arrangements			317,311
Stock options
Schedule of Earnings per Share [Line Items]
Incremental shares attributable to share-based arrangements			720,637