Selected Balance Sheet Data (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Accounts receivable, net:
Accounts receivable	$ 24,929	$ 26,772
Less allowance for doubtful accounts	295	339
Accounts receivable, net	24,634	26,433
Inventories:
Raw materials	18,159	18,960
Work in process	428	653
Finished goods	5,848	4,373
Inventories	24,435	23,986
Property, Plant and Equipment, Net [Abstract]
Total property, equipment and improvements, gross	44,744	44,827
Less accumulated depreciation and amortization	29,587	29,457
Total property, equipment and improvements, net	15,157	15,370	16,396
Land [Member]
Property, Plant and Equipment, Net [Abstract]
Total property, equipment and improvements, gross	1,800	1,800
Buildings [Member]
Property, Plant and Equipment, Net [Abstract]
Total property, equipment and improvements, gross	10,522	10,522
Improvements [Member]
Property, Plant and Equipment, Net [Abstract]
Total property, equipment and improvements, gross	3,763	3,916
Equipment [Member]
Property, Plant and Equipment, Net [Abstract]
Total property, equipment and improvements, gross	14,093	13,753
Purchased Software [Member]
Property, Plant and Equipment, Net [Abstract]
Total property, equipment and improvements, gross	11,971	11,801
Furniture and Fixtures [Member]
Property, Plant and Equipment, Net [Abstract]
Total property, equipment and improvements, gross	$ 2,595	$ 3,035