Quarterly Data - Quarterly Data (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 21,379,000	$ 22,135,000	$ 28,412,000	$ 17,651,000	$ 19,535,000	$ 20,363,000	$ 27,594,000	$ 16,878,000	$ 89,576,777	$ 84,369,770
Cost of goods sold	14,004,000	14,195,000	18,330,000	11,224,000	12,979,000	12,937,000	17,773,000	10,934,000	57,752,733	54,623,328
Net income	$ 524,000	$ 959,000	$ 2,211,000	$ 309,000	$ 430,000	$ 798,000	$ 2,061,000	$ 260,000	$ 4,002,905	$ 3,549,231
Basic earnings per share	$ 0.16	$ 0.30	$ 0.70	$ 0.10	$ 0.14	$ 0.26	$ 0.66	$ 0.08	$ 1.26	$ 1.14
Diluted earnings per share	$ 0.15	$ 0.29	$ 0.68	$ 0.10	$ 0.13	$ 0.26	$ 0.66	$ 0.08	$ 1.22	$ 1.13
Dividends per share	$ 0.08	$ 0.08	$ 0.08	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.31	$ 0.28