Statements of Stockholders' Equity (Unaudited) - USD ($)	Preferred Stock [Member]	Common Stock Class A [Member]	Paid-In Capital [Member]	Treasury Stock (Common Class A) [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]	Total
Balance at Apr. 30, 2018	$ 99,000	$ 850,000	$ 1,934,000	$ (4,148,000)	$ 2,249,000	$ 36,746,000	$ 37,730,000
Balance, shares at Apr. 30, 2018	4,100	8,502,881		3,534,784
Purchases of common stock				$ (5,000)			$ (5,000)
Purchases of common stock, shares				650
Unrealized gain (loss), net of tax effect					463,000		$ 463,000
Net Income						617,000	617,000
Balance at Jul. 31, 2018	$ 99,000	$ 850,000	1,934,000	$ (4,153,000)	2,712,000	37,363,000	38,805,000
Balance, shares at Jul. 31, 2018	4,100	8,502,881		3,535,434
Balance at Apr. 30, 2019	$ 99,000	$ 850,000	1,934,000	$ (4,227,000)	2,752,000	38,145,000	39,553,000
Balance, shares at Apr. 30, 2019	4,100	8,502,881		3,544,271
Purchases of common stock				$ (53,000)			(53,000)
Purchases of common stock, shares				6,300
Unrealized gain (loss), net of tax effect					138,000		138,000
Net Income						866,000	866,000
Balance at Jul. 31, 2019	$ 99,000	$ 850,000	$ 1,934,000	$ (4,280,000)	$ 2,890,000	$ 39,011,000	$ 40,504,000
Balance, shares at Jul. 31, 2019	4,100	8,502,881		3,550,571