Quarterly Financial Data (Unaudited) (Details) (USD $) In Thousands, except Per Share data	3 Months Ended	12 Months Ended
Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Summary of Quarterly Financial Data
Net Sales	$ 41,349	$ 40,052	$ 41,059	$ 37,263	$ 35,539	$ 33,857	$ 31,147	$ 42,457	$ 159,723	$ 143,000	$ 148,274
Gross Profit	24,488	25,351	25,957	23,502	21,267	21,803	20,222	25,404	99,298	88,696	92,442
Net earnings	$ 6,710	$ 6,836	$ 7,260	$ 6,025	$ 5,322	$ 6,424	$ 5,980	$ 8,921	$ 26,831	$ 26,647	$ 32,759
Basic earnings per common share	$ 0.16	$ 0.17	$ 0.18	$ 0.15	$ 0.13	$ 0.16	$ 0.15	$ 0.22	$ 0.66	$ 0.66	$ 0.81
Diluted earnings per common share	$ 0.16	$ 0.17	$ 0.18	$ 0.15	$ 0.13	$ 0.16	$ 0.15	$ 0.22	$ 0.65	$ 0.65	$ 0.80
Cash dividends per common share	$ 0.19	$ 0.19	$ 0.19	$ 0.19	$ 0.19	$ 0.19	$ 0.19	$ 0.17	$ 0.76	$ 0.74	$ 0.65

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References+ Details

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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