Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 03, 2015	Jun. 27, 2014	Jul. 03, 2015	Jun. 27, 2014	Sep. 26, 2014
Indefinite-lived Intangible Assets [Line Items]
Amortization expense for intangible assets	$ 1,800	$ 1,400	$ 5,112	$ 3,259
Future amortization expense, remaining fiscal year 2015	3,200		3,200
Future amortization expense, fiscal year 2016	9,500		9,500
Future amortization expense, fiscal year 2017	8,200		8,200
Future amortization expense, fiscal year 2018	6,100		6,100
Future amortization expense, fiscal year 2019	5,900		5,900
Future amortization expense, fiscal year 2020	4,400		4,400
Future amortization expense, thereafter	3,200		3,200
In Process Research and Development
Indefinite-lived Intangible Assets [Line Items]
Research and development asset acquired fair value	$ 1,800		$ 1,800		$ 2,000