Stock-Based Compensation (Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation before income taxes	$ 2,110	$ 1,882	$ 6,331	$ 5,323
Income tax benefit	(541)	(399)	(1,369)	(1,111)
Stock-based compensation after income taxes	1,569	1,483	4,962	4,212
Cost of Sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation before income taxes	98	80	269	222
Sales and Marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation before income taxes	614	609	1,762	1,669
Research and Development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation before income taxes	259	283	762	908
General and Administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation before income taxes	$ 1,132	$ 910	$ 3,538	$ 2,524