Goodwill and other Identifiable Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2012
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 82,902	$ 79,629
Accumulated amortization	(71,881)	(69,000)
Net	11,021	10,629
Purchased and Core Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	46,248	46,597
Accumulated amortization	(44,193)	(43,639)
Net	2,055	2,958
License Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,840	2,840
Accumulated amortization	(2,737)	(2,682)
Net	103	158
Patents and Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	11,924	10,943
Accumulated amortization	(9,302)	(8,469)
Net	2,622	2,474
Customer Maintenance Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	700	700
Accumulated amortization	(700)	(700)
Net	0	0
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	18,699	17,504
Accumulated amortization	(13,531)	(12,465)
Net	5,168	5,039
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,131	1,045
Accumulated amortization	(1,178)	(1,045)
Net	953	0
Order Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	360	0
Accumulated amortization	(240)	0
Net	$ 120	$ 0