Condensed Consolidated Statements of Operations and Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Sales	$ 178,131	$ 191,242	$ 377,631	$ 377,741
Cost of sales and other direct production costs	107,754	115,907	233,304	221,679
Depreciation, depletion and amortization	32,718	38,072	71,720	73,370
Total cost of sales	140,472	153,979	305,024	295,049
Gross profit	37,659	37,263	72,607	82,692
Other operating expenses:
General and administrative	10,783	9,692	22,853	17,986
Exploration and pre-development	6,893	11,200	11,860	24,008
Ramp-up and suspension costs	16,323	5,242	27,659	11,447
Provision for closed operations and environmental matters	3,111	1,472	4,155	2,373
Other operating (income) expense	(4,262)	1,945	(4,284)	4,408
Total other operating expenses	32,848	29,551	62,243	60,222
Income from operations	4,811	7,712	10,364	22,470
Other income (expense):
Interest expense	(10,311)	(10,505)	(20,476)	(20,911)
Fair value adjustments, net	(2,558)	(16,428)	623	(10,463)
Net foreign exchange gain (loss)	(3,850)	4,482	(3,742)	2,444
Other income	1,376	1,470	2,768	2,975
Total other expense	(15,343)	(20,981)	(20,827)	(25,955)
Income before income and mining taxes	(10,532)	(13,269)	(10,463)	(3,485)
Income and mining tax expense	(5,162)	(254)	(8,404)	(5,885)
Net (loss) income	(15,694)	(13,523)	(18,867)	(9,370)
Preferred stock dividends	(138)	(138)	(276)	(276)
Net (loss) income applicable to common stockholders	(15,832)	(13,661)	(19,143)	(9,646)
Comprehensive income (loss):
Net Income (Loss)	(15,694)	(13,523)	(18,867)	(9,370)
Change in fair value of derivative contracts designated as hedge transactions	5,232	65,348	11,748	32,183
Comprehensive income (loss)	$ (10,462)	$ 51,825	$ (7,119)	$ 22,813
Basic (loss) income per common share after preferred dividends	$ (0.03)	$ (0.03)	$ (0.03)	$ (0.02)
Diluted (loss) income per common share after preferred dividends	$ (0.03)	$ (0.03)	$ (0.03)	$ (0.02)
Weighted average number of common shares outstanding - basic	604,088,000	539,401,000	602,077,000	538,943,000
Weighted average number of common shares outstanding - diluted	604,088,000	539,401,000	602,077,000	538,943,000
Cash dividends declared per common share	$ 0.00625	$ 0.00625	$ 0.0125	$ 0.0125