Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2019	Jun. 30, 2019
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	3,029,874	3,029,874
Common stock, shares outstanding	2,401,033	2,401,213
Unearned ESOP, shares	7,083	14,166
Treasury stock, shares	628,841	628,661