Stock-Based Compensation - Stock Options By Range of Exercise Prices (Detail)	12 Months Ended
Dec. 27, 2017 $ / shares shares
$ 4.09
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices (usd per share)	$ 4.09
Number Outstanding (shares) \| shares	105,418
Weighted-Average Remaining Contractual Life (in Years)	5 years 5 months 23 days
Weighted-Average Exercise Price (usd per share)	$ 4.09
Number Exercisable (shares) \| shares	105,418
Weighted-Average Exercise Price (usd per share)	$ 4.09
$5.84
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices (usd per share)	$ 5.84
Number Outstanding (shares) \| shares	1,599,944
Weighted-Average Remaining Contractual Life (in Years)	4 years 5 months 27 days
Weighted-Average Exercise Price (usd per share)	$ 5.84
Number Exercisable (shares) \| shares	1,599,944
Weighted-Average Exercise Price (usd per share)	$ 5.84
$11.94 - 13.52
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, minimum (usd per share)	9.65
Range of exercise prices, maximum (usd per share)	$ 13.95
Number Outstanding (shares) \| shares	464,709
Weighted-Average Remaining Contractual Life (in Years)	8 years 8 months 5 days
Weighted-Average Exercise Price (usd per share)	$ 12.49
Number Exercisable (shares) \| shares	82,424
Weighted-Average Exercise Price (usd per share)	$ 11.99
$15.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices (usd per share)	$ 15.00
Number Outstanding (shares) \| shares	139,032
Weighted-Average Remaining Contractual Life (in Years)	6 years 6 months 29 days
Weighted-Average Exercise Price (usd per share)	$ 15.00
Number Exercisable (shares) \| shares	121,654
Weighted-Average Exercise Price (usd per share)	$ 15.00
$4.09 - 15.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, minimum (usd per share)	4.09
Range of exercise prices, maximum (usd per share)	$ 15.00
Number Outstanding (shares) \| shares	2,309,103
Weighted-Average Remaining Contractual Life (in Years)	5 years 6 months 4 days
Weighted-Average Exercise Price (usd per share)	$ 7.65
Number Exercisable (shares) \| shares	1,909,440
Weighted-Average Exercise Price (usd per share)	$ 6.59

Share-based compensation, shares authorized under stock option plans, options exercise price.

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(iii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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- Definition

Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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