Stock-Based Compensation (Stock-Based Compensation Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation before income taxes	$ 3,727	$ 3,444	$ 3,371
Income tax benefit	(1,240)	(1,143)	(1,121)
Stock-based compensation after income taxes	2,487	2,301	2,250
Cost of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation before income taxes	166	136	149
Selling and Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation before income taxes	1,271	1,156	1,185
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation before income taxes	724	771	739
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation before income taxes	$ 1,566	$ 1,381	$ 1,298