BUSINESS COMBINATIONS - Preliminary fair value of identifiable intangible assets (Details) - NRC - USD ($) $ in Thousands	Nov. 01, 2019	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total identified intangible assets	$ 252,100
Non-amortizing intangible assets		$ 57,100
Total identified intangible assets	309,500
Customer relationships - noncontractual
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total identified intangible assets	$ 199,600
Average Amortization Period	14 years
Customer relationships - contractual
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total identified intangible assets	$ 34,400
Average Amortization Period	7 years
Permits and licenses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total identified intangible assets	$ 8,700
Average Amortization Period	16 years
Tradename
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total identified intangible assets	$ 6,100
Average Amortization Period	2 years
Non-compete agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total identified intangible assets	$ 3,300
Average Amortization Period	2 years
Permits and license
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-amortizing intangible assets	$ 57,400