Equity (Schedule of Stock-based Compensation Expense - by Expense Category) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Expense:
Stock-based compensation expense	$ 7,756	$ 7,428	$ 9,860
Net effect on net loss per basic and diluted share (in dollars per share)	$ (0.33)	$ (0.32)	$ (0.48)
Cost of revenue
Expense:
Stock-based compensation expense	1,566	1,412	2,086
Selling, general and administrative
Expense:
Stock-based compensation expense	3,889	3,927	5,874
Research and development
Expense:
Stock-based compensation expense	$ 2,301	$ 2,089	$ 1,900