Goodwill and Other Identifiable Intangible Assets, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Sep. 30, 2015
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 76,526	$ 73,934
Accumulated amortization	(71,465)	(71,286)
Net	5,061	2,648
Purchased and Core Technology
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	47,190	45,449
Accumulated amortization	(45,345)	(45,424)
Net	1,845	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	11,491	11,377
Accumulated amortization	(10,550)	(10,385)
Net	941	992
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	17,827	17,090
Accumulated amortization	(15,566)	(15,473)
Net	$ 2,261	$ 1,617