Equity (Schedule of Common Stock Reserved for Future Issuances) (Details)	Mar. 31, 2013	Sep. 30, 2012
Equity [Abstract]
Exercise of outstanding stock options	1,768,833	2,032,215
Unvested restricted stock units	980,948
Purchases under the employee stock purchase plan	636,001
Issuance of stock-based awards under the Equity Plans	588,650
Exercise of outstanding warrants	400,001	750,011
Purchases under the officer and director share purchase plan	94,811
Total reserved	4,469,244