Days per share closing market price as reported on regulatory market

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- Definition

Share Based Compensation Arrangement by Share Based Payment Award, Expiration Term

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Percentage Used In Calculation To Determine Vesting

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

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-Paragraph A240

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

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-Section S99

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- Definition

Aggregate number of common shares reserved for future issuance.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

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-Subparagraph (SX 210.5-02.29)

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- Definition

As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period.

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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).

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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.

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- Definition

Restrictions on equity-based instruments during the vesting period, such as the inability to transfer unvested awards, are not taken into account in estimating the fair value of the award. However, restrictions that remain in effect after an award is vested, such as the inability to transfer or hedge vested options or a prohibition on the sale of outstanding vested shares (or other type of equity) for a period of time, affect the estimate of an award's fair value.

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- Definition

The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

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- Definition

Description of pertinent provisions of equity-based compensation awards that have actual or potential impact upon the company's financial statements.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph A240

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Share Based Payments Arrangements - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended				6 Months Ended				1 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 25, 2011	Jun. 30, 2012	Jun. 25, 2011	Jun. 30, 2012 Directors Stock Compensation Plan	Jun. 30, 2012 Other Stock Compensation Plan	Jun. 30, 2012 Stock Options	Jun. 25, 2011 Stock Options	Jun. 30, 2012 Non-Vested Restricted Stock	Dec. 31, 2011 Non-Vested Restricted Stock	Jan. 31, 2012 Restricted Stock Units (RSUs)	Jun. 30, 2012 Restricted Stock Units (RSUs)	Jun. 30, 2012 Restricted Stock Units (RSUs) Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit realized on disqualifying dispositions of stock acquired by exercise of incentive stock options			$ 745,000	$ 77,000
Common stock reserved for issuance					114,808	7,270,107
The weighted average grant date fair value of stock options granted							$ 13.99	$ 12.05
Total intrinsic value of stock options exercised during periods							12,296,000	871,000
Unrecognized compensation cost							8,929,000		1,101,000			5,000,000
Unrecognized compensation cost expected to be recognized over period, years							3 years 3 months 18 days		2 years 3 months 18 days			4 years 6 months
Contractual lives												5 years
Performance-related RSU awards issued									4,151		113,000
Stock units determined to vest, in years													5 years
Restricted stock units vesting description												The number of RSUs that vest is determined annually, for each year in the five-year period from date of grant, by multiplying the number of RSUs granted by the sum of (a) the average of the percentage change (positive or negative) in operating income and diluted earnings per share in each of the 5 years as compared to operating income and diluted earnings per share reported in the Company's 2011 fiscal year, plus (b) 5%, rounded to the nearest whole number, less (c) the number of RSUs previously vested.
Percentage used in calculation to determine vesting												5.00%
Days per share closing market price as reported on regulatory market												$ 48.15
Discount rate on stock awards												7.00%
Recognized share-based compensation expense	$ 1,661,000	$ 1,268,000	$ 3,186,000	$ 2,473,000								$ 430,000
Units outstanding									34,719	40,993		113,000