DEBT - Summary of Debt (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Weighted-average discount rate - finance leases	3.70%
Finance leases maturing through December 2107; bearing interest at a weighted average of 3.7%	$ 50,228	$ 49,813
Principal amount of debt	1,027,567	603,477
Less - unamortized debt issuance costs	11,476	9,494
Debt less unamortized debt issuance costs	1,016,091	593,983
Less—current maturities of debt	32,747	8,968
Debt, less current portion	$ 983,344	$ 585,015
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Debt, less current portion	Debt, less current portion
Secured Debt | Term loan A facility ("Term Loan Facility") due December 2026; bearing interest at Term SOFR plus 1.135%
Debt Instrument [Line Items]
Principal amount of debt	$ 350,000	$ 350,000
Secured Debt | Term loan A facility ("Term Loan Facility") due December 2026; bearing interest at Term SOFR plus 1.135% | SOFR
Debt Instrument [Line Items]
Variable rate margin	1.135%
Secured Debt | Term loan A facility ("2023 Term Loan Facility") due December 2026; bearing interest at Term SOFR plus 2.385%
Debt Instrument [Line Items]
Principal amount of debt	$ 430,000	0
Secured Debt | Term loan A facility ("2023 Term Loan Facility") due December 2026; bearing interest at Term SOFR plus 2.385% | SOFR
Debt Instrument [Line Items]
Variable rate margin	2.385%
Secured Debt | Revolving credit facility ("Revolving Credit Facility") due December 2026; bearing interest at Term SOFR plus 1.135% | SOFR
Debt Instrument [Line Items]
Variable rate margin	1.135%
Line of Credit | Revolving credit facility ("Revolving Credit Facility") due December 2026; bearing interest at Term SOFR plus 1.135%
Debt Instrument [Line Items]
Principal amount of debt	$ 0	6,000
Credit Facility | Revolving Credit Facility, Term Loan Facility and 2023 Term Loan Facility (collectively, the "Credit Facility")
Debt Instrument [Line Items]
Less - unamortized debt issuance costs	$ 7,087	4,716
Unsecured Debt | New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2014 ("New York Bonds 2014R-1") due December 2044 - fixed rate interest period ending in 2029; bearing interest at 2.875%
Debt Instrument [Line Items]
Stated interest rate	2.875%
Principal amount of debt	$ 25,000	25,000
Less - unamortized debt issuance costs	$ 832	866
Unsecured Debt | New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2014R-2 ("New York Bonds 2014R-2") due December 2044 - fixed rate interest period ending in 2026; bearing interest at 3.125%
Debt Instrument [Line Items]
Stated interest rate	3.125%
Principal amount of debt	$ 15,000	15,000
Less - unamortized debt issuance costs	$ 177	207
Unsecured Debt | New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2020 ("New York Bonds 2020") due September 2050 - fixed rate interest period ending in 2025; bearing interest at 2.750%
Debt Instrument [Line Items]
Stated interest rate	2.75%
Principal amount of debt	$ 40,000	40,000
Less - unamortized debt issuance costs	$ 1,016	1,106
Unsecured Debt | Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-3 ("FAME Bonds 2005R-3") due January 2025 - fixed rate interest period ending in 2025; bearing interest at 5.25%
Debt Instrument [Line Items]
Stated interest rate	5.25%
Principal amount of debt	$ 25,000	25,000
Less - unamortized debt issuance costs	$ 134	176
Unsecured Debt | Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2015R-1 ("FAME Bonds 2015R-1") due August 2035 - fixed rate interest period ending in 2025; bearing interest at 5.125%
Debt Instrument [Line Items]
Stated interest rate	5.125%
Principal amount of debt	$ 15,000	15,000
Less - unamortized debt issuance costs	$ 309	344
Unsecured Debt | Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2015R-2 ("FAME Bonds 2015R-2") due August 2035 - fixed rate interest period ending in 2025; bearing interest at 4.375%
Debt Instrument [Line Items]
Stated interest rate	4.375%
Principal amount of debt	$ 15,000	15,000
Less - unamortized debt issuance costs	$ 156	193
Unsecured Debt | Vermont Economic Development Authority Solid Waste Disposal Long-Term Revenue Bonds Series 2013 ("Vermont Bonds 2013") due April 2036 - fixed rate interest period ending in 2028; bearing interest at 4.625%
Debt Instrument [Line Items]
Stated interest rate	4.625%
Principal amount of debt	$ 16,000	16,000
Less - unamortized debt issuance costs	$ 351	378
Unsecured Debt | Vermont Economic Development Authority Solid Waste Disposal Long-Term Revenue Bonds Series 2022A-1 ("Vermont Bonds 2022A-1") due June 2052 - fixed rate interest period ending in 2027; bearing interest at 5.00%
Debt Instrument [Line Items]
Stated interest rate	5.00%
Principal amount of debt	$ 35,000	35,000
Less - unamortized debt issuance costs	$ 1,079	1,144
Unsecured Debt | Business Finance Authority of the State of New Hampshire Solid Waste Disposal Revenue Bonds Series 2013 ("New Hampshire Bonds") due April 2029 - fixed rate interest period ending in 2029; bearing interest at 2.95%
Debt Instrument [Line Items]
Stated interest rate	2.95%
Principal amount of debt	$ 11,000	11,000
Less - unamortized debt issuance costs	$ 335	364
Notes payable maturing through March 2025; bearing interest up to 8.1%
Debt Instrument [Line Items]
Stated interest rate	8.10%
Principal amount of debt	$ 339	$ 664