Property, Plant and Equipment and Rental Assets - Additional Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2019 USD ($) MW	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) MW	Sep. 30, 2018 USD ($)
Property, Plant and Equipment and Rental Assets
Value of C1000 Signature systems deployed under factory rental program \| $	$ 1.3		$ 2.0
Depreciation expense \| $	$ 0.4	$ 0.2	$ 0.7	$ 0.4
Capacity of fleet deployed \| MW	1.6
Capacity of fleet \| MW	6.2		6.2