Schedule of Information on Non - Vested Restricted Stock Units (Detail) - Non Vested Restricted Stock and Deferred Stock Units	3 Months Ended
Mar. 27, 2021 $ / shares shares
Number of Shares and Deferred Stock Units
Beginning Balance \| shares	60,440
Granted \| shares	18,078
Vested \| shares	(21,733)
Ending Balance \| shares	56,785
Weighted Average Grant Date Fair Value
Beginning Balance \| $ / shares	$ 103.65
Granted \| $ / shares	140.97
Vested \| $ / shares	103.39
Ending Balance \| $ / shares	$ 115.63

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).

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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).

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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

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-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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-Publisher FASB
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-Paragraph 2
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- Definition

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

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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.

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