Balance Sheets (Parenthetical) - USD ($)	Jun. 30, 2020	Jun. 30, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 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	3,029,874	3,029,874
Common stock, shares outstanding	2,402,633	2,401,213
Unearned ESOP, shares	0	14,166
Treasury stock, shares	627,241	628,661