Acquisition (Details) - USD ($) $ in Thousands		12 Months Ended
	Oct. 05, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Business Acquisition [Line Items]
Goodwill		$ 109,448	$ 100,183	$ 101,484
Bluenica Corporation
Business Acquisition [Line Items]
Cash, including cash in escrow	$ 2,888
Business combination contingent liability payout period	4 years
Business Combination, Consideration Transferred, Liabilities Incurred	$ 10,400
Acquisition related costs		100
Goodwill	$ 10,985
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years 7 months 13 days
Total revenue		$ 700
Purchased and Core Technology | Bluenica Corporation
Business Acquisition [Line Items]
Estimated useful life	5 years
Customer Relationships | Bluenica Corporation
Business Acquisition [Line Items]
Estimated useful life	7 years
Performance 1 [Member] | Bluenica Corporation
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability	$ 11,600
Performance 2 [Member] | Bluenica Corporation
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability	$ 3,500