Property, Plant and Equipment and Rental Assets - Additional Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2019 USD ($) MW	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) MW	Dec. 31, 2018 USD ($)
Property, Plant and Equipment and Rental Assets
Value of C1000 Signature systems deployed under factory rental program \| $	$ 0.7		$ 2.7
Depreciation expense \| $	$ 0.3	$ 0.3	$ 1.0	$ 0.8
Capacity of fleet deployed \| MW	0.8
Capacity of fleet \| MW	7.0		7.0