SHARE-BASED COMPENSATION - Weighted Average Assumptions Used in Estimating the Value of Stock Options Granted (Details) (USD $)	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
10-Year Standard Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	38.56%	37.62%	36.61%
Expected dividends	2.48%	0.51%	3.95%
Expected term (in years)	5.73	5.16	6.16
Risk-free rate	2.65%	2.52%	2.54%
Weighted average grant date fair value	$ 7.54	$ 5.28	$ 6.45
10-Year Executive Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility			36.51%
Expected dividends			3.95%
Expected term (in years)			7.08
Risk-free rate			2.75%
Weighted average grant date fair value			$ 6.69

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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