Schedule for Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 26, 2015
Income Tax Disclosure [Line Items]
Gross unrecognized tax benefits - beginning of the year	$ 2,704	$ 2,620
Gross increases related to current year tax positions	428	482
Gross increases related to prior year tax positions	596	340
Gross decreases related to prior year tax positions	(399)	(195)
Settlements	(133)
Lapse of statute of limitations	(561)	(543)
Gross unrecognized tax benefits - end of the year	$ 2,635	$ 2,704

Income Tax Disclosure [Line Items]

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- Definition

Amount of unrecognized tax benefits.

+ References

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=65882285&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

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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