NET INCOME PER SHARE - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic net income per share:
Net income	$ 32,756	$ 10,992
Weighted average common shares outstanding - Basic (in shares)	85,343	78,552
Basic net income per common share (in dollars per share)	$ 0.38	$ 0.14
Diluted net income per share:
Net income	$ 32,756	$ 10,992
Weighted average common shares outstanding - Basic (in shares)	85,343	78,552
Effect of dilutive securities:
Stock options and restricted stock (in shares)	915	1,282
Weighted average common shares for diluted earnings per share (in shares)	86,258	79,834
Diluted net income per common share (in dollars per share)	$ 0.38	$ 0.14