Income Taxes - Activity Related to Company's Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	6 Months Ended
Jun. 26, 2015	Jun. 27, 2014
Income Tax Disclosure [Abstract]
Balance as of the beginning of period	$ 356	$ 165
Increase (decrease) related to current year tax positions	(31)	141
Balance as of the end of period	$ 325	$ 306

Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15A

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=SL6600010-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Unrecognized Tax Benefit

-URI http://asc.fasb.org/extlink&oid=6527854

Name:	us-gaap_UnrecognizedTaxBenefits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant