Goodwill and other Identifiable Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2012
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 82,576	$ 79,629
Accumulated amortization	(70,638)	(69,000)
Net	11,938	10,629
Purchased and Core Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	46,177	46,597
Accumulated amortization	(43,847)	(43,639)
Net	2,330	2,958
Licensing Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,840	2,840
Accumulated amortization	(2,719)	(2,682)
Net	121	158
Patents and Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	11,729	10,943
Accumulated amortization	(9,018)	(8,469)
Net	2,711	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	18,641	17,504
Accumulated amortization	(13,083)	(12,465)
Net	5,558	5,039
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,129	1,045
Accumulated amortization	(1,121)	(1,045)
Net	1,008	0
Order Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	360	0
Accumulated amortization	150	0
Net	$ 210	$ 0