SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2021 USD ($)	Jan. 31, 2020 USD ($)	Jan. 31, 2021 USD ($)	Jan. 31, 2020 USD ($)
SEGMENT INFORMATION (Details) [Line Items]
Number of Reportable Segments			2
Revenues	$ 11,672	$ 9,628	$ 38,612	$ 31,270
Frequency Electronics Inc New York [Member]
SEGMENT INFORMATION (Details) [Line Items]
Number Of Principal Markets	3		3
Revenues	$ 9,411	7,234	$ 30,406	24,029
POC Revenue [Member]
SEGMENT INFORMATION (Details) [Line Items]
Revenues	10,815	8,542	35,556	28,482
POC Revenue [Member] | Frequency Electronics Inc New York [Member]
SEGMENT INFORMATION (Details) [Line Items]
Revenues	8,990	6,124	27,997	21,215
POT Revenue [Member]
SEGMENT INFORMATION (Details) [Line Items]
Revenues	857	1,086	3,056	2,788
POT Revenue [Member] | Frequency Electronics Inc New York [Member]
SEGMENT INFORMATION (Details) [Line Items]
Revenues	$ 421	$ 1,110	$ 2,409	$ 2,814