Summary of Accounting Policies (Details) - Disaggregation of Revenue - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 54,254	$ 41,507
Frequency Electronics Inc New York [Member]
Disaggregation of Revenue [Line Items]
Revenue	42,400	31,751
Frequency Electronics Inc Zyfer [Member]
Disaggregation of Revenue [Line Items]
Revenue	13,835	10,914
Inter Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue	(1,981)	(1,158)
POC Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue	50,208	37,842
POC Revenue [Member] | Frequency Electronics Inc New York [Member]
Disaggregation of Revenue [Line Items]
Revenue	39,225	28,720
POC Revenue [Member] | Frequency Electronics Inc Zyfer [Member]
Disaggregation of Revenue [Line Items]
Revenue	10,993	9,210
POC Revenue [Member] | Inter Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue	(10)	(88)
POT Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue	4,046	3,665
POT Revenue [Member] | Frequency Electronics Inc New York [Member]
Disaggregation of Revenue [Line Items]
Revenue	3,175	3,031
POT Revenue [Member] | Frequency Electronics Inc Zyfer [Member]
Disaggregation of Revenue [Line Items]
Revenue	2,842	1,704
POT Revenue [Member] | Inter Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ (1,971)	$ (1,070)