Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue		$ 204,123	$ 214,858	$ 392,527	$ 416,975
COSTS AND EXPENSES
Amortization		27,965	31,973	54,398	61,910
General and administrative		9,287	10,467	19,559	22,021
Pre-development, reclamation, and other		9,178	12,738	20,590	26,450
Total costs and expenses		202,388	200,219	389,190	373,235
OTHER INCOME (EXPENSE), NET
Loss on debt extinguishments		0	0	0	(9,173)
Fair value adjustments, net, pretax		(62,810)	37,239	(52,205)	33,440
Interest expense, net of capitalized interest		(5,170)	(5,093)	(9,738)	(10,003)
Other, net		313	701	2,050	4,328
Total other income (expense), net		(67,667)	32,847	(59,893)	18,592
Income (loss) before income and mining taxes		(65,932)	47,486	(56,556)	62,332
Income and mining tax (expense) benefit		(11,502)	(15,340)	(13,196)	(28,126)
NET INCOME (LOSS)		(77,434)	32,146	(69,752)	34,206
OTHER COMPREHENSIVE INCOME (LOSS), Net of Tax:
Unrealized gain (loss) on hedger, net of tax		34,245	(2,982)	29,027	24,376
Reclassification adjustments for realized (gain) loss on cash flow hedges		1,731	3,061	1,271	5,783
Other comprehensive income (loss)		32,514	(6,043)	27,756	18,593
COMPREHENSIVE INCOME (LOSS)		$ (44,920)	$ 26,103	$ (41,996)	$ 52,799
Basic EPS
Earnings Per Share, Basic		$ (0.28)	$ 0.13	$ (0.26)	$ 0.14
Diluted EPS
Earnings Per Share, Diluted		$ (0.28)	$ 0.13	$ (0.26)	$ 0.14
Accumulated Deficit [Member]
OTHER INCOME (EXPENSE), NET
NET INCOME (LOSS)		$ (77,434)	$ 32,146
Product
COSTS AND EXPENSES
Costs applicable to sales	[1]	150,679	132,595	$ 283,946	$ 240,742
Mineral, Exploration
COSTS AND EXPENSES
Costs applicable to sales		$ 5,279	$ 12,446	$ 10,697	$ 22,112

[1] Excludes amortization.