Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2021	Jun. 30, 2020
Statement of Financial Position [Abstract]
Trade accounts receivable, allowance	$ 3,000	$ 3,000
Common stock, par value	$ 0.3333	$ 0.3333
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares issued	3,129,874	3,029,874
Common stock, shares outstanding	2,702,633	2,402,633
Unearned ESOP, shares	288,245	0
Treasury stock, shares	427,241	627,241