Quarterly Data - Quarterly Data (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 19,535,000	$ 20,363,000	$ 27,594,000	$ 16,878,000	$ 15,836,000	$ 19,036,000	$ 24,029,000	$ 14,401,000	$ 84,369,770	$ 73,301,864
Cost of goods sold	12,979,000	12,937,000	17,773,000	10,934,000	10,142,000	12,396,000	15,346,000	9,093,000	54,623,328	46,976,944
Net income	$ 430,000	$ 798,000	$ 2,061,000	$ 260,000	$ 266,000	$ 682,000	$ 1,743,000	$ 120,000	$ 3,549,231	$ 2,811,193
Basic earnings per share	$ 0.14	$ 0.26	$ 0.66	$ 0.08	$ 0.08	$ 0.22	$ 0.56	$ 0.04	$ 1.14	$ 0.91
Diluted earnings per share	$ 0.13	$ 0.26	$ 0.66	$ 0.08	$ 0.09	$ 0.22	$ 0.55	$ 0.04	$ 1.13	$ 0.91
Dividends per share	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.06	$ 0.06	$ 0.28	$ 0.26