Goodwill and Intangible Assets - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Mar. 29, 2013	Mar. 30, 2012	Mar. 29, 2013	Mar. 30, 2012
Finite-Lived Intangible Assets [Line Items]
Amortization expense for intangible assets	$ 1,100,000	$ 800,000	$ 2,215,000	$ 1,716,000
Future amortization expense, remaining fiscal year 2013	2,100,000		2,100,000
Future amortization expense, fiscal year 2014	5,200,000		5,200,000
Future amortization expense, fiscal year 2015	5,800,000		5,800,000
Future amortization expense, fiscal year 2016	2,400,000		2,400,000
Future amortization expense, fiscal year 2017 and thereafter	$ 9,100,000		$ 9,100,000