Goodwill and other Identifiable Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2011
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 79,629	$ 78,766
Accumulated amortization	(69,000)	(64,406)
Net	10,629	14,360
Purchased and Core Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	46,597	46,412
Accumulated amortization	(43,639)	(41,716)
Net	2,958	4,696
Licensing Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,840	2,840
Accumulated amortization	(2,682)	(2,610)
Net	158	230
Patents and Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	10,943	10,341
Accumulated amortization	(8,469)	(7,505)
Net	2,474	2,836
Customer Maintenance Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	700	700
Accumulated amortization	(700)	(674)
Net	0	26
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	17,504	17,437
Accumulated amortization	(12,465)	(10,865)
Net	5,039	6,572
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,045	1,036
Accumulated amortization	(1,045)	(1,036)
Net	$ 0	$ 0