Restricted Stock Units Activity (Detail) (Restricted Stock Units (RSUs), USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended	12 Months Ended
Sep. 28, 2013	Dec. 31, 2012
Restricted Stock Units (RSUs)
Number of RSUs Outstanding
Number of outstanding, Beginning Balances	149,841
Number of outstanding, granted	682,498
Number of outstanding, Cancelled	(17,198)
Number of outstanding, Ending Balance	815,141	149,841
Number of outstanding, Vested and expected to vest	754,923
Weighted-Average Base Price
Weighted-Average Base Price, Beginning Balances	$ 11.12
Weighted-Average Grant Date Fair Value Per Award, granted	$ 21.31
Weighted-Average Base Price, Cancelled	$ 14.42
Weighted-Average Grant Date Fair Value Per Award, Ending Balance	$ 19.58	$ 11.12
Weighted-Average Grant Date Fair Value Per Award, Vested and expected to vest	$ 19.48
Weighted Average Remaining Contractual Life (in Years)	1 year 6 months 11 days	1 year 11 months 23 days
Weighted-Average Remaining Contractual Life (Years), Vested and expected to vest	1 year 5 months 16 days
Aggregate Intrinsic Value, Beginning Balance	$ 1,965
Aggregate Intrinsic Value, Ending Balance	31,888	1,965
Aggregate Intrinsic Value, Vested and expected to vest	$ 29,533

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Share Based Compensation Arrangement by Share Based Payment Award, Equity Instruments Other Than Options, Outstanding, Intrinsic Value

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Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested and Expected to Vest

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No definition available.

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Share based Compensation Arrangement by Share based Payment Award, Equity Instruments Other Than Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value

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No definition available.

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- Definition

Share based Compensation Arrangement by Share based Payment Award, Equity Instruments Other than Option, Vested and Expected to Vest Weighted Average Remaining Contractual Term

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No definition available.

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ 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)(iv)(3)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ 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)(2)(iii)(3)

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(i)-(ii)

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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-Publisher FASB

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-Paragraph 2

-Subparagraph (c)(2)(i)-(ii)

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- Definition

Weighted average remaining contractual term for equity-based awards excluding 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

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-Paragraph 2

-Subparagraph (e)(1)

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- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(2)

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