Stock-Based Compensation (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 25, 2011	Sep. 26, 2010	Sep. 25, 2011	Sep. 26, 2010
Share-based compensation expense	$ 1.4	$ 2.9	$ 6.2	$ 7.4
Share-based compensation expense net of tax	1.1	2.1	4.6	5.2
Actual tax benefit realized for tax deduction from option exercises			1.1	2.1
Stock Options And Awards [Member]
Total intrinsic value of options exercised			1.1	3.6
Unrecognized compensation cost	1.4		1.4
Weighted-average period over which unrecognized compensation cost will be recognized (years)			1.6
Restricted Stock Units (RSUs) [Member]
Unrecognized compensation cost	4.0		4.0
Weighted-average period over which unrecognized compensation cost will be recognized (years)			1.8
Total fair value of restricted stock awards			3.3	2.4
Time-Vested Cash Unit Awards [Member]
Deferred compensation arrangement liability, current and noncurrent	0.4	0.1	0.4	0.1
Deferred compensation arrangement with individual, share-based compensation expense	$ 0.2	$ 0.1	$ 0.4	$ 0.1
Vesting period			three

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.

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The amount of expense, net of income tax, 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.

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The compensation expense recognized during the period pertaining to the deferred compensation arrangement.

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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.

+ References

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-Publisher FASB

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The weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, using a decimal to express in number of years.

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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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Aggregate carrying value as of the balance sheet date of the liabilities for deferred compensation arrangements other than those specified elsewhere in the taxonomy.

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Description of the period of time over 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, which may be expressed in a variety of ways (for example, in years, month and year).

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The total fair value of equity-based awards 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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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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