|
Stock-Based Compensation (Schedule Of Weighted Average Assumptions) (Details) (USD $)
|
3 Months Ended | ||||
|---|---|---|---|---|---|
|
Mar. 31, 2012
Y
|
Mar. 31, 2011
Y
|
||||
|
Stock Option [Member]
|
|||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| Expected term, years | 4.51 | 4.98 | [1] | ||
| Expected stock price volatility | 32.44% | 30.87% | [1] | ||
| Risk-free interest rate | 0.87% | 1.82% | [1] | ||
| Expected dividend yield | 1.80% | 1.31% | [1] | ||
| Weighted average grant date fair value | $ 11.44 | $ 15.89 | [1] | ||
| Stock options granted | 323,615 | 314,701 | |||
|
Simplified Method [Member]
|
|||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| Stock options granted | 53,720 | ||||
| Vesting period | fifth anniversary of the grant date | ||||
|
|||||
| X | ||||||||||
|
- Definition
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). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- 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
|
| X | ||||||||||
|
- 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
|
| X | ||||||||||
|
- 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
|
| X | ||||||||||
|
- 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
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Net number of share options (or share units) granted during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- 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
|