Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2018	Jun. 30, 2018
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	2,396,323	2,387,124
Unearned ESOP, shares	21,666	29,166
Treasury stock, shares	633,551	642,750