Commitments and Contigencies (Details Textual) ozt in Millions				3 Months Ended		9 Months Ended		36 Months Ended
	Jan. 01, 2027	Aug. 26, 2025 USD ($)	Oct. 02, 2014 USD ($)	Sep. 30, 2025 USD ($) shares	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) shares	Sep. 30, 2024 USD ($)	Dec. 31, 2026	Jun. 30, 2025 USD ($)	Dec. 31, 2024 USD ($) shares	Jun. 30, 2024 USD ($)	Apr. 03, 2024 shares	Mar. 28, 2024 ozt	Dec. 31, 2023 USD ($)
Business Combination [Line Items]
Valued-added Tax Outstanding				$ 28,700,000		$ 28,700,000
Revenue Recognized				$ 153,000	$ 130,000	$ 42,661,000	$ 55,407,000
Common stock, shares issued (in shares) | shares				642,210,145		642,210,145				399,235,632
Surety Bonds Outstanding				$ 377,200,000		$ 377,200,000				$ 363,700,000
Minimum
Business Combination [Line Items]
Estimate of possible loss				0		0
Maximum
Business Combination [Line Items]
Estimate of possible loss				$ 12,000,000		$ 12,000,000
Kensington Royalty Matter | Settled Litigation
Business Combination [Line Items]
Royalty payment | ozt													2
Common stock, shares issued (in shares) | shares				595,267		595,267						737,210
Kensington Royalty Matter | Settled Litigation | Forecast
Business Combination [Line Items]
Royalty payment rate	1.50%							1.25%
U.S. Wage and Hour Matter | Settled Litigation
Business Combination [Line Items]
Payments for settlements		$ 6,100,000
Palmarejo gold production royalty
Business Combination [Line Items]
Production to be sold, percent			50.00%
Price per ounce under agreement			$ 800
Aggregate deposit to be received			$ 22,000,000.0
Franco-Nevada Gold Stream Agreement
Business Combination [Line Items]
Production to be sold, percent			50.00%
Total consideration			$ 78,000,000
Payments to acquire businesses, gross			75,000,000
Common shares issued (value)			$ 3,000,000
Kensington
Business Combination [Line Items]
Revenue Recognized				$ 0	(43,030,000)	$ (42,164,000)	(140,035,000)
Revenue liability				0	$ 55,080,000	0	$ 55,080,000		$ 0	$ 42,164,000	$ 43,282,000			$ 55,082,000
Rochester | June 2024 Prepayment
Business Combination [Line Items]
Revenue liability				17,500,000		17,500,000
Wharf | June 2024 Prepayment
Business Combination [Line Items]
Revenue liability				$ 12,500,000		$ 12,500,000