Commitments and Contingencies - Contract Liability (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Business Combination [Line Items]
Revenue Recognized	$ 153	$ 130	$ 42,661	$ 55,407
Franco-Nevada
Business Combination [Line Items]
Opening Balance	6,038	6,666	6,382	6,942
Revenue Recognized	(153)	(129)	(497)	(405)
Closing Balance	5,885	6,537	5,885	6,537
Kensington
Business Combination [Line Items]
Opening Balance	0	43,282	42,164	55,082
Additions	0	54,828	0	140,033
Revenue Recognized	0	(43,030)	(42,164)	(140,035)
Closing Balance	$ 0	$ 55,080	$ 0	$ 55,080