GOODWILL AND INTANGIBLE ASSETS - Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,480	$ 1,480
Accumulated Amortization	(320)	(80)
Net Carrying Amount	1,160	1,400
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	80	80
Accumulated Amortization	(40)	(10)
Net Carrying Amount	$ 40	$ 70
Average Remaining Amortization Useful Lives (in years)	1 year	1 year 9 months
Trade name
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 400	$ 400
Accumulated Amortization	(80)	(20)
Net Carrying Amount	$ 320	$ 380
Average Remaining Amortization Useful Lives (in years)	4 years	4 years 9 months
Customer lists
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,000	$ 1,000
Accumulated Amortization	(200)	(50)
Net Carrying Amount	$ 800	$ 950
Average Remaining Amortization Useful Lives (in years)	4 years	4 years 9 months