Goodwill and Intangible Assets Components of Identifiable Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2014
Finite-Lived Intangible Assets [Line Items]
Cost	$ 148,373	$ 141,848
Accumulated Amortization	88,680	82,298
Net Book Value	59,693us-gaap_FiniteLivedIntangibleAssetsNet	59,550us-gaap_FiniteLivedIntangibleAssetsNet
Patents
Finite-Lived Intangible Assets [Line Items]
Cost	7,808	7,808
Accumulated Amortization	7,347	7,300
Net Book Value	461	508
Completed Technology
Finite-Lived Intangible Assets [Line Items]
Cost	58,409	57,155
Accumulated Amortization	44,141	41,539
Net Book Value	14,268	15,616
Trademarks and Trade Names
Finite-Lived Intangible Assets [Line Items]
Cost	4,240	3,496
Accumulated Amortization	3,546	3,496
Net Book Value	694	0
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Cost	77,916	73,389
Accumulated Amortization	33,646	29,963
Net Book Value	$ 44,270	$ 43,426

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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