Summary of Significant Accounting Policies Summary of Unearned Income (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Oct. 02, 2014
Contract Liabilities
Revenue Recognized	$ 42,824,000	$ 55,562,000	$ 25,468,000
Palmarejo gold production royalty
Contract Liabilities
Aggregate deposit to be received				$ 22,000,000.0
Price per ounce under agreement				$ 800
Production to be sold, percent				50.00%
Franco-Nevada
Contract Liabilities
Opening Balance	6,382,000	6,942,000	7,411,000
Revenue Recognized	(660,000)	(560,000)	(469,000)
Closing Balance	5,722,000	6,382,000	6,942,000
Kensington
Contract Liabilities
Opening Balance	42,164,000	55,082,000	25,016,000
Additions	0	170,000,000	130,066,000
Revenue Recognized	(42,164,000)	(182,918,000)	(100,000,000)
Closing Balance	$ 0	$ 42,164,000	$ 55,082,000