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Stock-Based Compensation (Details 2) (USD $)
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6 Months Ended | 3 Months Ended | ||
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Jun. 30, 2011
Stock Option [Member]
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Jun. 30, 2010
Stock Option [Member]
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Jun. 30, 2011
Performance Retention Awards [Member]
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Feb. 03, 2011
Performance Retention Awards [Member]
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| Assumptions For Stock Awards [Abstract] | ||||
| Risk-free interest rate | 2.30% | 2.40% | ||
| Dividend yield | 1.60% | 1.80% | ||
| Expected life (years) | 5.30 | 5.40 | ||
| Volatility | 35.90% | 35.20% | ||
| Weighted-average grant-date fair value of options granted | $ 28.45 | $ 18.26 | ||
| Risk-free interest rate at date of grant | 1.20% | |||
| Continued employment requirement | Stock units awarded to selected employees under these grants are subject to continued employment for 37 months and the attainment of certain levels of ROIC. | |||
| Dividend per share for the quarter | $ 0.38 | |||
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- Definition
The risk-free interest rate assumption that is used in valuing an award on its own shares.
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- Definition
Description of the estimated period of time over which an employee is required to provide service in exchange for the share-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 amount of dividends per share to be paid to holders of the underlying shares (expected dividends) over the option's term. Dividends are taken into account because payment of dividends to shareholders reduces the fair value of the underlying shares, and option holders generally do not receive dividends.
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- Details
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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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The risk-free interest rate assumption that is used in valuing an option on its own shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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