Revenue Recognition - Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Revenue:
Total revenue	$ 20,609	$ 20,676	$ 53,887	$ 49,774
Product and accessories
Revenue:
Total revenue	12,329	12,760	29,183	26,572
Total from Micro turbine Products
Revenue:
Total revenue			28,234	25,396
Accessories and parts
Revenue:
Total revenue			949	1,176
Parts and service
Revenue:
Total revenue	$ 8,280	$ 7,916	24,704	23,202
Total North America
Revenue:
Total revenue			28,674	26,434
United States
Revenue:
Total revenue			26,052	23,237
Mexico
Revenue:
Total revenue			2,142	3,017
All other North America
Revenue:
Total revenue			480	180
Russia
Revenue:
Total revenue			3,099	2,725
All other Europe
Revenue:
Total revenue			8,911	10,780
Total Europe
Revenue:
Total revenue			12,010	13,505
Asia
Revenue:
Total revenue			1,755	3,455
Australia
Revenue:
Total revenue			3,861	2,319
All other
Revenue:
Total revenue			$ 7,587	$ 4,061