Acquisition (Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	Oct. 05, 2015	Jun. 30, 2016	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2014
Business Acquisition [Line Items]
Goodwill		$ 109,880	$ 100,183	$ 100,583	$ 101,484
Bluenica Corporation
Business Acquisition [Line Items]
Cash	$ 2,888
Purchase price payable upon completion of diligence matters	115
Fair value of contingent consideration on acquired business	10,400
Total purchase price consideration	13,403
Fair value of net tangible assets acquired	129
Goodwill	10,985
Deferred tax liabilities, net	(611)
Total assets acquired and liabilities assumed	13,403
Purchased and Core Technology | Bluenica Corporation
Business Acquisition [Line Items]
Fair value of identifiable intangible assets acquired	2,000
Customer Relationships | Bluenica Corporation
Business Acquisition [Line Items]
Fair value of identifiable intangible assets acquired	$ 900