Goodwill and Intangible Assets Components of Identifiable Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2012
Finite-Lived Intangible Assets [Line Items]
Cost	$ 145,010	$ 115,059
Accumulated Amortization	83,189	75,659
Net Book Value	61,821	39,400
Patents
Finite-Lived Intangible Assets [Line Items]
Cost	7,808	7,808
Accumulated Amortization	7,171	7,093
Net Book Value	637	715
Completed Technology
Finite-Lived Intangible Assets [Line Items]
Cost	65,035	54,583
Accumulated Amortization	45,928	42,751
Net Book Value	19,107	11,832
Trademarks and Trade Names
Finite-Lived Intangible Assets [Line Items]
Cost	4,011	4,014
Accumulated Amortization	3,935	3,880
Net Book Value	76	134
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Cost	68,156	48,654
Accumulated Amortization	26,155	21,935
Net Book Value	$ 42,001	$ 26,719