LEASES - Schedule of Lease Costs and Other Lease Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Lease cost:
Amortization of right-of-use assets	$ 2,122
Interest expense	767
Fixed lease cost	17,271
Short-term lease cost	3,878
Variable lease cost	190
Total lease cost	24,228
Cash paid for amounts included in the measurement of lease liabilities:
Financing cash flows for finance leases	2,601
Operating cash flows for operating leases	13,840
Right-of-use assets obtained in exchange for new finance lease liabilities	9,433
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 3,351
Weighted-average remaining lease term - finance leases (years)	6 years 6 months
Weighted-average remaining lease term - operating leases (years)	12 years
Weighted-average discount rate - finance leases	5.00%
Weighted-average discount rate - operating leases	5.10%
Machinery and equipment
Lease cost:
Fixed lease cost	$ 9,560
Landfills
Lease cost:
Fixed lease cost	$ 7,711