Property, Plant and Equipment (Tables)	6 Months Ended
Property, Plant and Equipment (Tables)	Jun. 30, 2026
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	(in US$ thousands) June 30, 2026 December 31, 2025 Land $ 24,029 $ 29,008 Buildings and improvements 142,762 138,771 Plant, machinery, mining equipment and transportation vehicles 1,258,397 1,516,095 Mineral rights and reserves 245,473 370,393 Office and computer equipment 20,235 20,063 Mine development 674,390 694,779 Asset retirement obligation asset 66,689 79,094 Construction in process 92,261 103,011 Total cost of property, plant and equipment 2,524,236 2,951,214 Less: accumulated depreciation, depletion, amortization and impairment 1,090,854 1,296,759 Property, plant and equipment, net $ 1,433,382 $ 1,654,455