INCOME TAXES - Provision (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current provision:
Federal									$ 10,001	$ 2,202	$ 9,750
State									3,267	1,813	3,264
Foreign									413	2,060	2,238
Current tax provision									13,681	6,075	15,252
Deferred provision (benefit):
Federal									5,948	4,196	1,157
State									1,789	1,221	737
Foreign									(22)	(6)	(22)
Deferred tax provision									7,715	5,411	1,872
Total provision (benefit) for income taxes	$ 6,285	$ 9,774	$ 4,854	$ 483	$ (6,478)	$ 7,072	$ 9,184	$ 1,708	$ 21,396	$ 11,486	$ 17,124