Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Sales	$ 191,242	$ 217,983	$ 377,741	$ 428,835
Cost of sales and other direct production costs	115,907	110,320	221,679	207,029
Depreciation, depletion and amortization	38,072	45,732	73,370	92,474
Total cost of sales	153,979	156,052	295,049	299,503
Gross profit	37,263	61,931	82,692	129,332
Other operating expenses:
General and administrative	9,692	11,104	17,986	19,111
Exploration and pre-development	11,200	11,241	24,008	17,931
Care and maintenance costs	5,242	5,786	11,447	10,104
Provision for closed operations and environmental matters	1,472	1,024	2,373	4,733
Other operating expense	1,945	3,634	4,408	7,282
Total other operating expenses	29,551	32,789	60,222	59,161
Income from operations	7,712	29,142	22,470	70,171
Other income (expense):
Interest expense	(10,505)	(10,271)	(20,911)	(21,015)
Fair value adjustments, net	16,428	18,063	10,463	19,938
Net foreign exchange gain (loss)	4,482	(1,907)	2,444	(3,971)
Other income (expense)	1,470	(287)	2,975	(439)
Total other expense	(20,981)	(30,528)	(25,955)	(45,363)
(Loss) income before income and mining taxes	(13,269)	(1,386)	(3,485)	24,808
Income and mining tax (provision) benefit	(254)	4,134	(5,885)	(609)
Net (loss) income	(13,523)	2,748	(9,370)	24,199
Preferred stock dividends	(138)	(138)	(276)	(276)
(Loss) income applicable to common shareholders	(13,661)	2,610	(9,646)	23,923
Comprehensive income (loss):
Net (loss) income	(13,523)	2,748	(9,370)	24,199
Change in fair value of derivative contracts designated as hedge transactions	65,348	1,620	32,183	3,452
Comprehensive income	$ 51,825	$ 4,368	$ 22,813	$ 27,651
Basic (loss) income per common share after preferred dividends (in dollars per share)	$ (0.03)	$ 0.01	$ (0.02)	$ 0.04
Diluted (loss) income per common share after preferred dividends (in dollars per share)	$ (0.03)	$ 0.01	$ (0.02)	$ 0.04
Weighted average number of common shares outstanding - basic (in shares)	539,401	535,531	538,943	534,819
Weighted average number of common shares outstanding - diluted (in shares)	539,401	542,262	538,943	541,468
Cash dividends declared per common share (in dollars per share)	$ 0.00625	$ 0.01	$ 0.01225	$ 0.02