Property, Plant and Equipment

6 Months Ended

Jun. 30, 2022

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

6.Property, Plant and Equipment

(in US$ thousands)	June 30, 2022		December 31, 2021
Land	$	27,197	$	27,853
Buildings and improvements		92,604		88,079
Plant, machinery, mining equipment and transportation vehicles		992,728		963,272
Mineral rights and reserves		374,326		374,326
Office and computer equipment		9,274		8,718
Mine development		557,596		566,201
Asset retirement obligation asset		70,584		75,215
Construction in process		49,257		42,055
		2,173,566		2,145,719
Less accumulated depreciation, depletion and amortization		810,194		748,356
Net property, plant and equipment	$	1,363,372	$	1,397,363