GOODWILL AND OTHER INTANGIBLE ASSETS - Estimated Future Annual Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2020	$ 11,611
2021	9,287
2022	7,974
2023	6,508
2024	4,886
Thereafter	12,316
Carrying Amount, net	52,582	$ 67,207	$ 78,525
Customer relationships
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Carrying Amount, net	$ 52,486	67,055
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets, weighted average useful life	7 years 3 months 29 days
Non-compete agreements
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Carrying Amount, net	$ 96	$ 152
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets, weighted average useful life	2 years 6 months 29 days