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DEBT - Components of Debt (Details) - USD ($) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2023 | Dec. 31, 2022
Debt Instrument [Line Items] |  |
Weighted-average discount rate - finance leases | 4.00% |
Finance leases maturing through December 2107; bearing interest at a weighted average of 4.0% | $ 53,066,000 | $ 49,813,000
Principal amount of debt | 1,054,546,000 | 603,477,000
Less—unamortized discount and debt issuance costs | 11,103,000 | 9,494,000
Debt less unamortized debt issuance costs | 1,043,443,000 | 593,983,000
Less—current maturities of debt | 35,781,000 | 8,968,000
Debt, less current portion | $ 1,007,662,000 | $ 585,015,000
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 7.083% as of December 31, 2023 |  |
Debt Instrument [Line Items] |  |
Principal amount of debt | $ 350,000,000 | $ 350,000,000
Secured Debt | Term Loan A Facility ("2023 Term Loan Facility") due December 2026; bearing interest at 7.581% as of December 31, 2023 |  |
Debt Instrument [Line Items] |  |
Principal amount of debt | 419,250,000 | 0
Line of Credit | Revolving Credit Facility ("Revolving Credit Facility") due December 2026; bearing interest at Term SOFR plus 1.725% |  |
Debt Instrument [Line Items] |  |
Principal amount of debt | 0 | 6,000,000
Unsecured Debt |  |
Debt Instrument [Line Items] |  |
Principal amount of debt | $ 232,000,000 |
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 bearing interest at 2.875% through December 2029 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 2.875% |
Principal amount of debt | $ 25,000,000 | 25,000,000
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 bearing interest at 3.125% through May 2026 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 3.125% |
Principal amount of debt | $ 15,000,000 | 15,000,000
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 bearing interest at 2.750% through September 2025 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 2.75% |
Principal amount of debt | $ 40,000,000 | 40,000,000
Unsecured Debt | New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2020R-2 ("New York Bonds 2020R-2") due September 2050 - fixed rate interest period bearing interest at 5.125% through September 2030 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 5.125% |
Principal amount of debt | $ 35,000,000 | 0
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 bearing interest at 5.25% through January 2025 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 5.25% |
Principal amount of debt | $ 25,000,000 | 25,000,000
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 bearing interest at 5.125% through July 2025 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 5.125% |
Principal amount of debt | $ 15,000,000 | 15,000,000
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 bearing interest at 4.375% through July 2025 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 4.375% |
Principal amount of debt | $ 15,000,000 | 15,000,000
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 bearing interest at 4.625% through April 2028 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 4.625% |
Principal amount of debt | $ 16,000,000 | 16,000,000
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 bearing interest at 5.00% through May 2027 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 5.00% |
Principal amount of debt | $ 35,000,000 | 35,000,000
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 bearing interest at 2.95% through April 2029 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 2.95% |
Principal amount of debt | $ 11,000,000 | 11,000,000
Notes payable maturing through March 2025; bearing interest up to 8.1% |  |
Debt Instrument [Line Items] |  |
Weighted average interest rate | 8.10% |
Principal amount of debt | $ 230,000 | $ 664,000
SOFR | Secured Debt | Term Loan A Facility ("Term Loan Facility") due December 2026; bearing interest at 7.083% as of December 31, 2023 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 7.083% |
SOFR | Secured Debt | Term Loan A Facility ("2023 Term Loan Facility") due December 2026; bearing interest at 7.581% as of December 31, 2023 |  |
Debt Instrument [Line Items] |  |
Stated interest rate | 7.581% |
SOFR | Line of Credit | Revolving Credit Facility ("Revolving Credit Facility") due December 2026; bearing interest at Term SOFR plus 1.725% |  |
Debt Instrument [Line Items] |  |
Basis spread on variable rate | 1.725% |

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