Zinc Zero Cost Collar (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Realized loss on zinc zero cost collar	$ 1,160	$ 359	$ 2,026	$ 450
Unrealized gain on zinc zero cost collar	(3,324)	310	(2,156)	184
Total	3,799		(338)
Zinc
Derivative Instruments, Gain (Loss) [Line Items]
Realized loss on zinc zero cost collar	1,220	159	1,649	160
Unrealized gain on zinc zero cost collar	(2,550)	$ 37	(1,962)	$ 120
Zero Cost Collar \| Zinc
Derivative Instruments, Gain (Loss) [Line Items]
Realized loss on zinc zero cost collar	300
Zero Cost Collar \| Zinc \| Not designated as hedge
Derivative Instruments, Gain (Loss) [Line Items]
Realized loss on zinc zero cost collar	829		2,457
Unrealized gain on zinc zero cost collar	(4,628)		(2,119)
Total	$ (3,799)		$ 338

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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The difference between the book value and the sale price of options, swaps, futures, forward contracts, and other derivative instruments. This element refers to the gain (loss) included in earnings.

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The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period.

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