Amortization Expense Associated with Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2010
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 6,944	[1]	$ 7,741	[1]	$ 10,901	[1]
Cost of revenues
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	1,332		2,274		5,415
Selling, general and administrative expenses
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 5,612		$ 5,467		$ 5,486

[1] Cost of revenues and selling, general and administrative expenses exclude the amortization of intangible assets. See Note 7 to consolidated financial statements.