Goodwill and Other Identifiable Intangible Assets, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Sep. 30, 2015
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 76,038	$ 73,934
Accumulated amortization	(71,615)	(71,286)
Net	4,423	2,648
Purchased and Core Technology
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	46,772	45,449
Accumulated amortization	(45,050)	(45,424)
Net	1,722	25
License Agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	18	18
Accumulated amortization	(4)	(4)
Net	14	14
Patents and Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	11,689	11,377
Accumulated amortization	(10,858)	(10,385)
Net	831	992
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	17,559	17,090
Accumulated amortization	(15,703)	(15,473)
Net	$ 1,856	$ 1,617