NET INCOME (LOSS) PER SHARE - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Basic net income (loss) per share:
Net income (loss)	$ (369)	$ 9,180	$ 29,736	$ 32,756	$ 8,811	$ 62,492
Weighted average common shares outstanding - Basic (in shares)	84,706		85,577		84,955	85,460
Basic net income (loss) per common share (in dollars per share)	$ 0.00		$ 0.35		$ 0.10	$ 0.73
Diluted net income (loss) per share:
Net income (loss)	$ (369)	$ 9,180	$ 29,736	$ 32,756	$ 8,811	$ 62,492
Weighted average common shares outstanding - Basic (in shares)	84,706		85,577		84,955	85,460
Effect of dilutive securities:
Stock options and restricted stock (in shares)	0		680		593	947
Weighted average common shares for diluted earnings per share (in shares)	84,706		86,257		85,548	86,407
Diluted net income (loss) per common share (in dollars per share)	$ 0.00		$ 0.34		$ 0.10	$ 0.72