Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net (loss) income	$ (108,881,000)	$ 156,065,000	$ 771,703,000
Adjustments to reconcile net income to cash and cash equivalents provided by operating activities:
Depreciation, depletion and amortization	190,923,000	163,862,000	165,503,000
Change in estimate of asset retirement obligation	(3,523,000)	(3,151,000)	1,543,000
Impairment of non-core assets	10,585,000	0	0
Amortization of right of use asset - operating leases	22,091,000	12,415,000	6,704,000
Amortization of deferred financing costs	3,989,000	4,300,000	1,933,000
Non-cash interest expense	34,912,000	30,997,000	31,362,000
Amortization of contract obligations	(31,443,000)	(33,026,000)	(36,519,000)
Equity-based compensation expense	129,000	2,149,000	2,735,000
Loss on debt extinguishment	14,732,000	1,385,000	5,336,000
Deferred income taxes	(39,526,000)	(21,338,000)	40,423,000
Reclamation of asset retirement obligations	(9,724,000)	(5,334,000)	(4,543,000)
(Decrease) increase in provision for discounting and credit losses	(207,000)	(4,216,000)	3,821,000
Gain on translation of short-term inter-entity balances	(10,028,000)	0	0
Other	(694,000)	516,000	855,000
Changes in operating assets and liabilities:
Accounts receivable - including related party receivables, net	35,451,000	155,056,000	(156,818,000)
Inventories	27,644,000	(32,774,000)	(41,243,000)
Other current assets	(2,778,000)	(477,000)	(12,365,000)
Accounts payable	(9,366,000)	40,159,000	(27,664,000)
Accrued expenses and other current liabilities	(97,895,000)	(25,435,000)	84,041,000
Operating lease liabilities	(21,050,000)	(14,597,000)	(8,244,000)
Income tax payable	66,665,000	(164,834,000)	96,326,000
Change in other liabilities	2,033,000	6,560,000	1,754,000
Net cash provided by operating activities	74,039,000	268,282,000	926,643,000
Cash flows from investing activities:
Capital expenditures	(248,142,000)	(237,205,000)	(199,716,000)
Proceeds from the disposal of property, plant, and equipment	0	0	318,000
Purchase of restricted and other deposits	(2,462,000)	(27,213,000)	(9,761,000)
Redemption of restricted and other deposits	24,268,000	26,250,000	816,000
Net cash used in investing activities	(226,336,000)	(238,168,000)	(208,343,000)
Cash flows from financing activities:
Proceeds from interest bearing liabilities and other financial liabilities	449,860,000	0	0
Debt issuance costs and other financing costs	(13,912,000)	(3,436,000)	0
Principal payments on interest bearing liabilities and other financial liabilities	(246,668,000)	(4,361,000)	(81,310,000)
Call premiums paid on early redemption of debt	(9,768,000)	0	(2,557,000)
Principal payments on finance lease obligations	(68,000)	(127,000)	(140,000)
Dividends paid	(16,679,000)	(16,755,000)	(700,244,000)
Net cash provided by (used in) financing activities	162,765,000	(24,679,000)	(784,251,000)
Net increase (decrease) in cash and cash equivalents	10,468,000	5,435,000	(65,951,000)
Effect of exchange rate changes on cash and cash equivalents	(10,138,000)	(769,000)	(37,351,000)
Cash and cash equivalents at beginning of period	339,295,000	334,629,000	437,931,000
Cash and cash equivalents at end of period	339,625,000	339,295,000	334,629,000
Supplemental disclosure of cash flow information:
Cash payments for interest	29,727,000	28,632,000	36,728,000
Cash (refund) paid for taxes	(67,842,000)	147,106,000	90,888,000
Restricted cash	$ 251,000	$ 251,000	$ 251,000