Statements of Comprehensive Income - USD ($)	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net sales	$ 6,279,436	$ 5,693,472
Cost of sales	4,311,116	3,883,393
Gross profit	1,968,320	1,810,079
Selling, general and administrative expenses	749,650	598,202
Operating income	1,218,670	1,211,877
Other income
Interest income	7,453	7,993
Other	17,988	9,657
Total other income	25,441	17,650
Income before income taxes	1,244,111	1,229,527
Provision for income taxes	365,581	318,306
Net income	878,530	911,221
Other comprehensive income, net of tax:
Unrealized gain (loss) on investment securities	1,779	(320)
Total comprehensive income	$ 880,309	$ 910,901
Net income per share:
Basic	$ 0.38	$ 0.40
Diluted	$ 0.38	$ 0.40
Weighted average number of shares outstanding:
Basic	2,284,124	2,270,949
Diluted	2,303,805	2,277,754
Dividends per share:	$ 0.25	$ 0.25