EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net income	$ 65,082	$ 10,927
Denominator:
Weighted average basic shares (in shares)	47,509,205	51,086,316
Dilutive potential common shares (in shares)	283,000	78,000
Weighted average fully diluted shares (in shares)	47,792,108	51,164,224
Earnings per share:
Basic (in dollars per share)	$ 1.37	$ 0.21
Diluted (in dollars per share)	$ 1.36	$ 0.21
Outstanding common stock equivalents having no dilutive effect (in shares)	3,000	10,000