Goodwill and Intangible Assets - Amortization Expense Associated with Intangible Assets (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	[1]	$ 3,486	$ 3,599	$ 10,573	$ 10,046
Cost of revenues
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets		1,805	1,919	5,552	5,656
Selling, general and administrative expenses
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets		$ 1,681	$ 1,680	$ 5,021	$ 4,390

[1] Cost of revenues and selling, general and administrative expenses exclude the amortization of intangible assets. See Note 5.