NET INCOME PER SHARE - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Basic net income per share:
Net income	$ 43,229	$ 35,068	$ 45,394	$ 32,337	$ (369)	$ 9,180	$ 123,691	$ 41,148
Weighted average common shares outstanding - Basic (in shares)	84,754			84,325			84,647	84,745
Basic net income (loss) per common share (in dollars per share)	$ 0.51			$ 0.38			$ 1.46	$ 0.49
Diluted net income per share:
Net income	$ 43,229	$ 35,068	$ 45,394	$ 32,337	$ (369)	$ 9,180	$ 123,691	$ 41,148
Weighted average common shares outstanding - Basic (in shares)	84,754			84,325			84,647	84,745
Effect of dilutive securities:
Stock options and restricted stock (in shares)	693			427			744	558
Weighted average common shares for diluted earnings per share (in shares)	85,447			84,752			85,391	85,303
Diluted net income (loss) per common share (in dollars per share)	$ 0.51			$ 0.38			$ 1.45	$ 0.48