Commitments and Contingencies (Details) $ in Thousands, T in Millions	3 Months Ended
	Mar. 31, 2022 USD ($) T	Dec. 31, 2021 USD ($)	May 29, 2020
Unrecorded Unconditional Purchase Obligation [Line Items]
Royalty payment, percentage of net profit	4.00%
Royalty payment, annual advance	$ 120
Royalty payment, additional incremental payment	$ 120
Royalty payment, annual tons mined threshold | T	5.0
Royalty payment, maximum lease payments	$ 7,600
Payments to acquire royalty interests in mining properties	$ 3,000
Smelter royalty obligation, percentage			1.50%
Royalty obligation, metal price discount rate	5.00%
Royalty obligation
Unrecorded Unconditional Purchase Obligation [Line Items]
Royalty obligation, fair value	$ 154,000	$ 154,000
Other assets, noncurrent
Unrecorded Unconditional Purchase Obligation [Line Items]
Payments to acquire royalty interests in mining properties	$ 600