Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net sales	$ 6,470,286	$ 6,549,623	$ 17,860,841	$ 20,040,219
Cost of sales	5,032,752	4,870,498	12,354,493	15,269,944
Gross profit	1,437,534	1,679,125	5,506,348	4,770,275
Selling, general and administrative expenses	765,900	762,329	1,997,279	2,316,864
Operating income	671,634	916,796	3,509,069	2,453,411
Other income
Interest income	9,362	10,231	26,416	30,646
Other	5,024	49,717	25,618	95,854
Total other income	14,386	59,948	52,034	126,500
Income before income taxes	686,020	976,744	3,561,103	2,579,911
Provision for income taxes	179,651	270,714	924,431	713,822
Net income	506,369	706,030	2,636,672	1,866,089
Other comprehensive income, net of tax:
Unrealized (loss) gain on investment securities	(259)	(569)	(1,672)	(919)
Total comprehensive income	$ 506,110	$ 705,461	$ 2,635,000	$ 1,865,170
Net income per share:
Basic	$ 0.22	$ 0.31	$ 1.16	$ 0.83
Diluted	$ 0.22	$ 0.31	$ 1.15	$ 0.82
Weighted average number of shares outstanding:
Basic	2,271,105	2,249,175	2,269,157	2,240,834
Diluted	2,297,071	2,294,616	2,286,312	2,285,904
Dividends per share:	$ 0.2500	$ 0.2500	$ 0.7500	$ 1.7500