Goodwill and Intangible Assets Components of Identifiable Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Sep. 30, 2015
Finite-Lived Intangible Assets [Line Items]
Cost	$ 191,593	$ 150,513
Accumulated Amortization	105,947	95,067
Net Book Value	85,646	55,446
Patents
Finite-Lived Intangible Assets [Line Items]
Cost	7,808	7,808
Accumulated Amortization	7,463	7,394
Net Book Value	345	414
Completed Technology
Finite-Lived Intangible Assets [Line Items]
Cost	60,441	60,748
Accumulated Amortization	49,982	46,718
Net Book Value	10,459	14,030
Trademarks and Trade Names
Finite-Lived Intangible Assets [Line Items]
Cost	9,143	4,241
Accumulated Amortization	4,028	3,604
Net Book Value	5,115	637
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Cost	114,201	77,716
Accumulated Amortization	44,474	37,351
Net Book Value	$ 69,727	$ 40,365