1. Summary of Accounting Policies (Details) - Disaggregation of Revenue - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 49,509	$ 39,407
POC Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue	45,329
POT Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue	4,180
Frequency Electronics Inc New York [Member]
Disaggregation of Revenue [Line Items]
Revenue	38,096	26,936
Frequency Electronics Inc New York [Member] | POC Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue	35,588
Frequency Electronics Inc New York [Member] | POT Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue	2,508
Frequency Electronics Inc Zyfer [Member]
Disaggregation of Revenue [Line Items]
Revenue	12,235	15,272
Frequency Electronics Inc Zyfer [Member] | POC Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue	9,803
Frequency Electronics Inc Zyfer [Member] | POT Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue	2,432
Inter Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue	(822)	$ (2,801)
Inter Segment [Member] | POC Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue	(62)
Inter Segment [Member] | POT Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ (760)