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 income tax provision:
Federal									$ 9,232	$ 4,985	$ 7,985
State									559	1,212	1,751
Total									9,791	6,197	9,736
Deferred income tax (benefit)/provision:
Federal									(14,125)	(6,274)	(4,630)
State									744	(2,027)	(556)
Foreign									345	1,000	(214)
Total									(13,036)	(7,301)	(5,400)
Change in valuation allowance									(169)	(1,833)	221
Total (benefit)/provision for income taxes	$ 1,253	$ (371)	$ (1,443)	$ (2,853)	$ (2,817)	$ 64	$ (653)	$ 469	$ (3,414)	$ (2,937)	$ 4,557