Summary of Significant Accounting Policies Summary of Unearned Income (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Oct. 02, 2014
Contract Liabilities
Deferred Revenue Recognized	$ 10,115,000	$ 315,000
Palmarejo gold production royalty
Contract Liabilities
Aggregate deposit to be received			$ 22,000,000
Price per ounce under agreement			$ 800
Production to be sold, percent			50.00%
Franco-Nevada
Contract Liabilities
Opening Balance	7,411,000	8,150,000
Deferred Revenue Recognized	(115,000)	(315,000)
Closing Balance	7,296,000	7,835,000
Kensington
Contract Liabilities
Opening Balance	25,016,000	15,016,000
Deferred Revenue, Additions	111,000	10,139,000
Deferred Revenue Recognized	(10,000,000)	0
Closing Balance	$ 15,127,000	$ 25,155,000