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EMPLOYEE STOCK BENEFIT PLANS (Fair Value Assumptions) (Details) (Market share units [Member])	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Market share units [Member]
Fair Value Assumptions [Line Items]
Expected volatility	24.10%	24.30%	24.80%
Risk-free interest rate	0.60%	1.80%	1.90%
Dividend yield	4.40%	4.90%	5.80%

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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