Goodwill and other Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount		$ 76,874	$ 80,413
Accumulated amortization		(72,695)	(73,628)
Net		4,179	6,785
Intangible impairment charge	$ 361	0	0	$ 361
Purchased and Core Technology
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount		45,449	45,952
Accumulated amortization		(45,424)	(45,162)
Net		25	790
Intangible impairment charge	200
License Agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount		18	2,440
Accumulated amortization		(4)	(2,440)
Net		14	0
Intangible impairment charge	100
Patents and Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount		11,817	11,667
Accumulated amortization		(10,568)	(9,799)
Net		1,249	1,868
Intangible impairment charge	$ 100
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount		18,490	18,894
Accumulated amortization		(16,057)	(15,445)
Net		2,433	3,449
Non-compete Agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount		1,100	1,100
Accumulated amortization		(642)	(422)
Net		458	678
Order Backlog
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount		0	360
Accumulated amortization		0	(360)
Net		$ 0	$ 0