Commitments and Contingencies - Contract Liability (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Business Combination [Line Items]
Revenue Recognized	$ 138	$ 192	$ 298	$ 42,508
Franco-Nevada
Business Combination [Line Items]
Opening Balance	5,562	6,230	5,722	6,382
Revenue Recognized	(138)	(192)	(298)	(344)
Closing Balance	5,424	6,038	5,424	6,038
Kensington
Business Combination [Line Items]
Opening Balance	0	0	0	42,164
Additions	0	0	0	0
Revenue Recognized	0	0	0	(42,164)
Closing Balance	$ 0	$ 0	$ 0	$ 0