INTANGIBLE ASSETS - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 213,445	$ 214,095
Accumulated Amortization	(130,229)	(124,197)
Net Carrying Amount	83,216	89,898
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	174,774	175,156
Accumulated Amortization	(94,627)	(88,783)
Net Carrying Amount	80,147	86,373
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,411	5,503
Accumulated Amortization	(5,411)	(5,503)
Net Carrying Amount	0	0
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	24,614	24,743
Accumulated Amortization	(22,432)	(22,252)
Net Carrying Amount	2,182	2,491
Technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	7,809	7,843
Accumulated Amortization	(6,966)	(6,885)
Net Carrying Amount	843	958
Licenses
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	837	850
Accumulated Amortization	(793)	(774)
Net Carrying Amount	$ 44	$ 76