STOCK-BASED EMPLOYEE COMPENSATION (Stock Options) (Details) - Employee Stock Option [Member] - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Number of Shares
Beginning balance (in shares)	30,675
Exercised (in shares)	(3,300)
Forfeited (in shares)	(13)
Ending balance (in shares)	27,362.000		30,675
Weighted-Average Exercise Price
Beginning balance (in dollars per share)	$ 401.61
Exercised (in dollars per share)	493.87
Forfeited (in dollars per share)	241.83
Ending balance (in dollars per share)	$ 390.64		$ 401.61
Aggregate Intrinsic Value	$ 43,598		$ 40,986
Weighted Average Remaining Contractual Term	3 years		3 years 11 months
Vested and exercisable at September 30, 2018
Number of Shares	27,289
Weighted Average Exercise Price (in dollars per share)	$ 399.10
Aggregate Intrinsic Value	$ 43,541
Weighted Average Remaining Contractual Term, Exercisable	3 years
Vested and exercisable at September 30, 2018 and expected to vest thereafter
Number of Shares	27,362
Weighted Average Exercise Price (in dollars per share)	$ 390.64
Aggregate Intrinsic Value	$ 43,598
Weighted Average Remaining Contractual Term	3 years
Stock options exercised, total intrinsic value	$ 5,100	$ 21,400
Options, vested, number of shares (in shares)	98	1,246

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest exercisable options that may be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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