Property, plant and equipment - Schedule of Right-of-Use Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Mar. 31, 2022
Property, Plant and Equipment [Line Items]
Less: accumulated depreciation	$ (2,068)	$ (2,984)
Right of use assets, net	3,270	4,340
Property
Property, Plant and Equipment [Line Items]
Right of use property and equipment, gross	5,113	7,019
Equipment, motor vehicles and other
Property, Plant and Equipment [Line Items]
Right of use property and equipment, gross	$ 225	$ 305