CLOSURE AND POST-CLOSURE LIABILITIES - Anticipated Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Environmental Property Sale, Disposal or Abandonment Costs
2024	$ 15,698
2025	16,694
2026	14,750
2027	3,955
2028	13,628
Thereafter	252,110
Undiscounted closure and post-closure liabilities	316,835
Less: Discount at credit-adjusted risk-free rate	(114,325)
Less: Undiscounted estimated closure and post-closure liabilities relating to airspace not yet consumed	(83,910)
Present value of closure and post-closure liabilities	$ 118,600	$ 118,801	$ 99,103