Summary of Information Regarding Stock Options (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 28, 2015
Number of Options
Beginning Balance, number of options	773,839
Exercised, number of options	(48,700)
Forfeited, number of options	(1,000)
Ending Balance, number of options	724,139
Options exercisable at the ending, Number of Options	495,239
Weighted Average Exercise Price per Share
Beginning Balance, Weighted Average Exercise Price per Share	$ 46.92
Exercised, Weighted Average Exercise Price per Share	$ 45.52
Forfeited, Weighted Average Exercise Price per Share	$ 52.60
Ending Balance, Weighted Average Exercise Price per Share	$ 47.01
Options exercisable at March 28, 2015	$ 45.09
Weighted Average Remaining Contractual Term (years)
Options outstanding at March 28, 2015	5 years 6 months
Options exercisable at March 28, 2015	4 years 10 months 24 days
Aggregate Intrinsic Value
Options outstanding at March 28, 2015	$ 13,572
Options exercisable at March 28, 2015	$ 10,232

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Number of share options (or share units) exercised during the current period.

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