Consolidated Statements of Comprehensive Income (Loss) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019
Revenue		$ 229,728,000	$ 199,469,000	$ 557,144,000		$ 516,462,000
COSTS AND EXPENSES
Amortization		32,216,000	45,678,000	96,254,000		130,758,000
General and administrative		7,757,000	9,635,000	25,293,000		26,859,000
Pre-development, reclamation, and other		15,031,000	4,851,000	40,261,000		13,619,000
Total costs and expenses		180,594,000	207,009,000	514,571,000		591,112,000
OTHER INCOME (EXPENSE), NET
Loss on debt extinguishments		0	(1,282,000)	0		(1,282,000)
Fair value adjustments, net, pretax		2,243,000	4,377,000	3,491,000		8,201,000
Interest expense, net of capitalized interest		(5,096,000)	(5,980,000)	(15,989,000)		(19,259,000)
Other, net		(6,312,000)	(3,634,000)	(4,310,000)		(2,931,000)
Total other income (expense), net		(9,165,000)	(6,519,000)	(16,808,000)		(15,271,000)
Total		39,969,000	(14,059,000)	25,765,000		(89,921,000)
Income and mining tax (expense) benefit		(13,113,000)	(218,000)	(12,018,000)		13,986,000
Income (loss) from continuing operations		26,856,000	(14,277,000)	13,747,000		(75,935,000)
Income (loss) from discontinued operations		0	0	0		5,693,000
NET INCOME (LOSS)		26,856,000	(14,277,000)	13,747,000		(70,242,000)
Other comprehensive income (loss), derivatives qualifying as hedges, tax, portion attributable to parent		0	365,000	0		365,000
OTHER COMPREHENSIVE INCOME (LOSS), Net of Tax:
Unrealized gain (loss) on hedger, net of tax		(18,606,000)	1,132,000	(26,176,000)		1,132,000
Unrealized gain (loss) on debt and equity securities		0	0	0		59,000
Other comprehensive income (loss)		(18,606,000)	1,132,000	(26,176,000)		1,191,000
COMPREHENSIVE INCOME (LOSS)		$ 8,250,000	$ (13,145,000)	$ (12,429,000)		$ (69,051,000)
Basic EPS
Income (Loss) from Continuing Operations, Per Basic Share		$ 0.11	$ (0.06)	$ 0.06		$ (0.36)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share		0	0	0		0.03
Earnings Per Share, Basic		0.11	(0.06)	0.06	[1]	(0.33)	[1]
Diluted EPS
Income (Loss) from Continuing Operations, Per Diluted Share		0.11	(0.06)	0.06		(0.36)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share		0	0	0		0.03
Earnings Per Share, Diluted		$ 0.11	$ (0.06)	$ 0.06	[1]	$ (0.33)	[1]
Accumulated Deficit [Member]
OTHER INCOME (EXPENSE), NET
NET INCOME (LOSS)		$ 26,856,000	$ (14,277,000)	$ 13,747,000
Product
COSTS AND EXPENSES
Costs applicable to sales	[2]	112,772,000	140,952,000	321,704,000		$ 404,550,000
Mineral, Exploration
COSTS AND EXPENSES
Costs applicable to sales		$ 12,818,000	$ 5,893,000	$ 31,059,000		$ 15,326,000

[1] Due to rounding, the sum of net income per share from continuing operations and discontinued operations may not equal net income per share.

[2] Excludes amortization.