Goodwill - Additional Information (Detail) - Segments	12 Months Ended
Sep. 24, 2016	Sep. 26, 2015	Sep. 27, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Number of reportable segments	2
Fair value of reporting segments exceeds carrying value, percentage		10.00%	10.00%

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

No definition available.

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration