Goodwill and other Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 75,694	$ 73,934
Accumulated amortization	(71,653)	(71,286)
Net	4,041	2,648
Purchased and Core Technology
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	46,594	45,449
Accumulated amortization	(44,999)	(45,424)
Net	1,595	25
License Agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	18	18
Accumulated amortization	(10)	(4)
Net	8	14
Patents and Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	11,619	11,377
Accumulated amortization	(10,871)	(10,385)
Net	748	992
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	17,463	17,090
Accumulated amortization	(15,773)	(15,473)
Net	$ 1,690	$ 1,617