Revenue Recognition - Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Revenue:
Total revenue	$ 18,652	$ 16,082
Product and accessories
Revenue:
Total revenue	9,167	8,389
Total from Micro turbine Products
Revenue:
Total revenue	8,965	8,312
Accessories and parts
Revenue:
Total revenue	202	77
Parts, service and rentals
Revenue:
Total revenue	9,485	7,693
Total North America
Revenue:
Total revenue	12,917	7,823
United States
Revenue:
Total revenue	11,676	7,343
Mexico
Revenue:
Total revenue	610	441
All other North America
Revenue:
Total revenue	631	39
Russia
Revenue:
Total revenue	340	1,257
All other Europe
Revenue:
Total revenue	3,635	2,785
Total Europe
Revenue:
Total revenue	3,975	4,042
Asia
Revenue:
Total revenue	471	364
Australia
Revenue:
Total revenue	714	1,411
All other
Revenue:
Total revenue	$ 575	$ 2,442