Balance Sheets (Parenthetical) - USD ($)	Jun. 30, 2017	Jun. 30, 2016
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 3,000	$ 3,000
Advance payments	$ 1,366,504	$ 18,313
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	2,371,321	2,364,684
Unearned ESOP, shares	45,000	61,667
Treasury stock, shares	658,553	665,190