EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator for basic and diluted earnings per share:
Net income	$ 85,565	$ 60,754
Numerator for basic and diluted earnings per share	$ 85,565	$ 60,754
Denominator:
Weighted average common shares for basic earnings per share	55,286,747	54,245,133
Net effect of dilutive stock options, restricted stock units and restricted stock awards	2,855,823	2,991,294
Weighted average common shares for diluted earnings per share	58,142,570	57,236,427
Net income per share:
Basic (in dollars per share)	$ 1.55	$ 1.12
Diluted (in dollars per share)	$ 1.47	$ 1.06
Anti-dilutive options not included in the calculation (in shares)	9,118	26,203