Revenue Recognition - Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue:
Total revenue	$ 68,926	$ 83,412
Product, accessories and parts
Revenue:
Total revenue	48,143	66,303
Total from Micro turbine Products
Revenue:
Total revenue	33,790	51,417
Accessories and parts
Revenue:
Total revenue	14,353	14,886
Service
Revenue:
Total revenue	20,783	17,109
Total North America
Revenue:
Total revenue	34,588	51,276
United States
Revenue:
Total revenue	31,082	45,480
Mexico
Revenue:
Total revenue	2,361	5,005
All other North America
Revenue:
Total revenue	1,145	791
Russia
Revenue:
Total revenue	3,653	3,176
All other Europe
Revenue:
Total revenue	12,858	12,886
Total Europe
Revenue:
Total revenue	16,511	16,062
Asia
Revenue:
Total revenue	4,074	5,229
Australia
Revenue:
Total revenue	4,559	3,874
All other
Revenue:
Total revenue	$ 9,194	$ 6,971