Equity (Schedule of Common Stock Reserved for Future Issuances) (Details) - shares	Mar. 31, 2016	Sep. 30, 2015
Equity [Abstract]
Exercise of outstanding stock options	617,947	696,459
Unvested restricted stock units	590,995
Purchases under the employee stock purchase plan	881,706
Issuance of stock-based awards under the Equity Plans	837,887
Purchases under the officer and director share purchase plan	88,741
Issuance of deferred stock-based awards under the Directors' Stock Award Plan, as amended	22,163
Total reserved	3,039,439