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SHARE-BASED COMPENSATION - Weighted Average Assumptions Used to Remeasure the Value of Stock Appreciation Rights (Detail) (Stock appreciation rights, USD $)	3 Months Ended
	Mar. 31, 2013 Rate
Stock appreciation rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	25.48%
Expected dividends	2.17%
Expected term (in years)	1 year 120 days
Risk-free rate	0.20%
Weighted average fair value	$ 8.93

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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