Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue		$ 207,969	$ 229,728	$ 624,944	$ 557,144
COSTS AND EXPENSES
Amortization		30,962	32,216	92,872	96,254
General and administrative		8,743	7,757	30,764	25,293
Pre-development, reclamation, and other		10,506	15,031	36,956	40,261
Total costs and expenses		199,942	180,594	573,177	514,571
OTHER INCOME (EXPENSE), NET
Loss on debt extinguishments		0	0	(9,173)	0
Fair value adjustments, net, pretax		(26,440)	2,243	7,000	3,491
Interest expense, net of capitalized interest		(3,237)	(5,096)	(13,240)	(15,989)
Other, net	[1]	(26,718)	(6,312)	(22,390)	(4,310)
Total other income (expense), net		(56,395)	(9,165)	(37,803)	(16,808)
Income (loss) before income and mining taxes		(48,368)	39,969	13,964	25,765
Income and mining tax (expense) benefit		(6,400)	(13,113)	(34,526)	(12,018)
NET INCOME (LOSS)		(54,768)	26,856	(20,562)	13,747
OTHER COMPREHENSIVE INCOME (LOSS), Net of Tax:
Unrealized gain (loss) on hedger, net of tax		1,349	(21,248)	25,723	(28,139)
Reclassification adjustments for realized (gain) loss on cash flow hedges		3,902	(2,642)	9,683	(1,963)
Other comprehensive income (loss)		(2,553)	(18,606)	16,040	(26,176)
COMPREHENSIVE INCOME (LOSS)		$ (57,321)	$ 8,250	$ (4,522)	$ (12,429)
Basic EPS
Earnings Per Share, Basic		$ (0.21)	$ 0.11	$ (0.08)	$ 0.06
Diluted EPS
Earnings Per Share, Diluted		$ (0.21)	$ 0.11	$ (0.08)	$ 0.06
Accumulated Deficit [Member]
OTHER INCOME (EXPENSE), NET
NET INCOME (LOSS)		$ (54,768)	$ 26,856
Product
COSTS AND EXPENSES
Costs applicable to sales	[2]	134,340	112,772	$ 375,082	$ 321,704
Mineral, Exploration
COSTS AND EXPENSES
Costs applicable to sales		$ 15,391	$ 12,818	$ 37,503	$ 31,059

[1] See Note 14 -- Additional Comprehensive Income (Loss) Detail for additional detail

[2] Excludes amortization.