BUSINESS Prior Period Revisions (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended	9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	May 20, 2021	Dec. 31, 2020	Dec. 31, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	$ (170)	$ 102		$ 347			$ (255)	$ (425)	$ 325
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	(17,797)	(5,111)		(6,297)			(18,188)	(35,985)	(32,482)
Stockholders' Equity Attributable to Parent	326,841	341,333	$ 159,267	178,538	$ 179,699	$ 189,889	341,333	326,841	178,538		$ 171,718	$ 109,760
Temporary Equity, Foreign Currency Translation Adjustments	(170)	102	(357)	347	142	(164)
Intangible assets, net	56,343	58,218					58,218	56,343			13,883
Goodwill	75,583	75,828					75,828	75,583		$ 75,583	0
Other assets	447	375					375	447			546
Assets	390,000	400,384					400,384	390,000			214,401
Accumulated other comprehensive income	1,699	1,869					1,869	1,699			2,124
Accumulated Other Comprehensive Income (Loss) [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity Attributable to Parent	1,699	1,869	1,767	1,790	1,513	1,460	1,869	$ 1,699	$ 1,790		$ 2,124	$ 1,434
Temporary Equity, Foreign Currency Translation Adjustments	$ (170)	102	$ (357)	$ 347	$ 142	$ (164)
Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax		(3,070)					(3,427)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent		(8,283)					(21,360)
Stockholders' Equity Attributable to Parent		338,161					338,161
Temporary Equity, Foreign Currency Translation Adjustments		(3,070)
Intangible assets, net		57,015					57,015
Goodwill		73,845					73,845
Other assets		389					389
Assets		397,212					397,212
Accumulated other comprehensive income		(1,303)					(1,303)
Previously Reported | Accumulated Other Comprehensive Income (Loss) [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity Attributable to Parent		(1,303)					(1,303)
Revision of Prior Period, Error Correction, Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax		3,172					3,172
Comprehensive Income (Loss), Net of Tax, Attributable to Parent		3,172					3,172
Stockholders' Equity Attributable to Parent		3,172					3,172
Temporary Equity, Foreign Currency Translation Adjustments		3,172
Intangible assets, net		1,203					1,203
Goodwill		1,983					1,983
Other assets		(14)					(14)
Assets		3,172					3,172
Accumulated other comprehensive income		3,172					3,172
Revision of Prior Period, Error Correction, Adjustment | Accumulated Other Comprehensive Income (Loss) [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity Attributable to Parent		$ 3,172					$ 3,172