Share-Based Compensation (Assumption For Fair Value Of Options Granted) (Details)	3 Months Ended	6 Months Ended
Jun. 30, 2011 years	Jun. 30, 2010 years	Jun. 30, 2011 years	Jun. 30, 2010 years
Stock Option Plans [Member]
Risk-free interest rate			2.60%	2.50%
Expected volatility			27.40%	42.10%
Weighted average expected life in years			7.4	4.5
Dividend yield			3.70%	3.50%
Employee Stock [Member]
Risk-free interest rate	0.04%	0.20%	0.04%	0.20%
Expected volatility	25.00%	34.00%	25.00%	34.00%
Weighted average expected life in years	1.0	1.0	1.0	1.0
Dividend yield	3.70%	3.50%	3.70%	3.50%

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.

+ References+ Details

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.

+ References+ Details