Goodwill and Other Identifiable Intangible Assets, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Sep. 30, 2015
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 76,596	$ 73,934
Accumulated amortization	(71,801)	(71,286)
Net	4,795	2,648
Purchased and Core Technology
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	47,165	45,449
Accumulated amortization	(45,352)	(45,424)
Net	1,813	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	11,596	11,377
Accumulated amortization	(10,710)	(10,385)
Net	886	992
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	17,817	17,090
Accumulated amortization	(15,735)	(15,473)
Net	$ 2,082	$ 1,617