INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
INCOME TAXES
Income taxes	$ 6,658	$ 14,797	$ 51,259	$ 41,834
Pre-tax income	38,415	$ 73,303	$ 253,429	$ 182,908
Effective tax rate			20.20%	22.90%
Unrecognized tax benefits	17,733		$ 17,733
Unrecognized tax benefits that, if recognized, would be reflected as a component of income tax expense	14,008		14,008
Reasonably possible further reduction in prior years' unrecognized tax benefits during the next twelve months	$ 937		$ 937