Reconciliation of Average Number of Common Shares Outstanding to Average Number of Diluted Shares Outstanding (Detail)	3 Months Ended
Mar. 30, 2013	Mar. 31, 2012
Earnings Per Share Disclosure [Line Items]
Average number of common shares outstanding	46,507,000	46,800,000
Incremental shares from assumed exercises of stock options	215,000	261,000
Average number of common shares and common share equivalents outstanding	46,722,000	47,061,000

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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