Amortization of Acquired Intangible Assets Included in Costs of Goods Sold and Operating Expense Categories (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 28, 2012
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	$ 351
Cost of Goods Sold
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	247
Selling, General and Administrative
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	$ 104