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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Description of the estimated period of time over which an employee is required to provide service in exchange for the equity-based payment award, which often is the vesting period. This period may be explicit or implicit based on the terms of the award, and may be presented in a variety of ways (for example, year, month and year, day, month and year, quarter of a year).

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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The period of time an equity-based award is expected to be outstanding. An equity-based award's expected term is generally determined based on, among other factors, the instrument's contractual term and the effects of employees' expected exercise and post-vesting employment termination behavior.

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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Net number of share options (or share units) granted during the period.

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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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Common Stock Plans (2004 Stock Appreciation Rights Plan) (Details) (2004 Stock Appreciation Rights Plan, Stock Appreciation Rights, USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended				12 Months Ended
	Jan. 26, 2011 year	Jan. 27, 2010 year	Feb. 16, 2009 year	Jan. 28, 2009 year	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
2004 Stock Appreciation Rights Plan \| Stock Appreciation Rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense					$ 4.3	$ 3.4	$ 4.6
Remaining requisite service period (in years)					3 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Awards granted	189,984	171,749	3,292	305,257
Fair market value of stock at grant	$ 15.43	$ 16.43	$ 21.98	$ 22.93
Expected life of award	5.6	4.6	3.6	3.6
Risk-free interest rate	1.05%	0.77%	0.53%	0.53%
Annualized volatility rate	39.50%	39.50%	39.50%	39.50%
Dividend yield	1.10%	1.10%	1.10%	1.10%