NET INCOME PER COMMON SHARE - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator:
NET INCOME	$ 10,365	$ 1,949
Adjustment for Basic EPS:
Earning allocated to unvested shareholders	(191)	(32)
Adjusted net income	$ 10,174	$ 1,917
Denominator:
Weighted average common shares outstanding – Basic	46,661,559	46,774,360
Effect of dilutive shares:
Common stock equivalents arising from stock options and ESPP	2,151	9,442
Restricted stock awards and units and performance units	79,184	123,756
Weighted average common shares outstanding – Diluted	46,742,894	46,907,558
Basic	$ 0.22	$ 0.04
Diluted	$ 0.22	$ 0.04