SHARE-BASED COMPENSATION Weighted Average Assumptions Used in Estimating the Value of Performance Share Units Granted (Details) - Performance share units	6 Months Ended
Jun. 30, 2018 $ / shares Rate
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Valuation date average stock price (1) \| $ / shares	$ 34.14
Expected dividends	3.81%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	1/1/2018
Risk-free rate minimum	1.75%
Expected volatility minimum	17.30%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	12/31/2020
Risk-free rate maximum	2.34%
Expected volatility maximum	21.52%

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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iii)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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The estimated measure of the maximum 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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The estimated measure of the minimum 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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- Definition

The maximum risk-free interest rate assumption that is used in valuing an option on its own shares.

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The minimum risk-free interest rate assumption that is used in valuing an option on its own shares.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Price of a single share of a number of saleable stocks of a company.

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Share Based Compensation Arrangement by Share Based Payment Award, Performance Period.

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