Stock Based Compensation (Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs) (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]
Allocated share-based compensation expense	$ 5,031	$ 4,042	$ 2,497
Tax effect on stock-based compensation	0	0	0
Net effect on net income	5,031	4,042	2,497
Cost of sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	135	157	134
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	1,461	1,078	849
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	$ 3,435	$ 2,807	$ 1,514