Summarized Quarterly Results of Operations (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2012	Sep. 30, 2011
Summarized quarterly results of operations
Net sales	$ 31,549	$ 30,968	$ 34,079	$ 28,510	$ 30,282	$ 28,875	$ 26,804	$ 21,396	$ 125,106	$ 107,357
Cost of goods sold	25,332	23,047	26,601	22,045	22,542	22,075	19,878	16,421	97,025	80,916
Income before income tax provision	1,669	3,302	2,696	1,733	3,500	2,879	3,002	1,857	9,400	11,238
Income tax provision	472	861	972	547	1,316	815	1,007	651	2,852	3,789
Net income	$ 1,197	$ 2,441	$ 1,724	$ 1,186	$ 2,184	$ 2,064	$ 1,995	$ 1,206	$ 6,548	$ 7,449
Net income per share:
Basic	$ 0.22	$ 0.46	$ 0.32	$ 0.22	$ 0.41	$ 0.39	$ 0.38	$ 0.23	$ 1.23	$ 1.41
Diluted	$ 0.22	$ 0.46	$ 0.32	$ 0.22	$ 0.41	$ 0.39	$ 0.38	$ 0.23	$ 1.22	$ 1.40