Property, Plant, and Equipment, Net - Depreciation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Cost of goods and services sold
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 26,035	$ 26,532	$ 26,967
Operating expense
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 3,351	$ 3,157	$ 2,382