CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($)	Common Stock [Member]	Capital Contributed in Excess of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Total
Balance at Apr. 30, 2020	$ 836,000	$ 51,334,000	$ 43,149,000	$ (6,467,000)	$ (4,215,000)	$ 84,637,000
Balance (in shares) at Apr. 30, 2020	8,358
Issuance of restricted common stock	$ 1,000	41,000	0	0	0	42,000
Issuance of restricted common stock (in shares)	9
Net income	$ 0	0	593,000	0	0	593,000
Other comprehensive income	0	0	0	90,000	0	90,000
Balance at Jul. 31, 2020	$ 837,000	51,375,000	43,742,000	(6,377,000)	(4,215,000)	85,362,000
Balance (in shares) at Jul. 31, 2020	8,367
Balance at Apr. 30, 2021	$ 730,000	45,072,000	47,710,000	(4,623,000)	0	88,889,000
Balance (in shares) at Apr. 30, 2021	7,323
Issuance of restricted common stock	$ 1,000	149,000	0	0	0	150,000
Issuance of restricted common stock (in shares)	13
Net income	$ 0	0	1,637,000	0	0	1,637,000
Other comprehensive income	0	0	0	66,000	0	66,000
Balance at Jul. 31, 2021	$ 731,000	$ 45,221,000	$ 49,347,000	$ (4,557,000)	$ 0	$ 90,742,000
Balance (in shares) at Jul. 31, 2021	7,336