Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2017	Jun. 30, 2016
Statement of Financial Position [Abstract]
Trade accounts receivable, allowance	$ 3,000	$ 3,000
Advance payments of costs related to contracts in process	$ 16,692	$ 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	49,167	61,667
Treasury stock, shares	658,553	665,190