Property, Plant and Equipment	6 Months Ended
Property, Plant and Equipment	Jun. 30, 2025
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	6. Property, Plant and Equipment (in US$ thousands) June 30, 2025 December 31, 2024 Land $ 28,732 $ 28,130 Buildings and improvements 131,741 123,662 Plant, machinery, mining equipment and transportation vehicles 1,388,134 1,259,620 Mineral rights and reserves 372,817 379,065 Office and computer equipment 19,400 9,654 Mine development 575,035 550,110 Asset retirement obligation asset 94,068 90,318 Construction in process 259,580 190,124 Total cost of property, plant and equipment 2,869,507 2,630,683 Less accumulated depreciation, depletion and amortization 1,203,446 1,123,553 Property, plant and equipment, net $ 1,666,061 $ 1,507,130