STOCK-BASED EMPLOYEE COMPENSATION (Stock Options) (Details) - Employee Stock Option [Member] - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Number of Shares
Beginning balance (in shares)	30,675
Exercised (in shares)	(2,770)
Forfeited (in shares)	(13)
Ending balance (in shares)	27,892.000		30,675
Weighted-Average Exercise Price
Beginning balance (in dollars per share)	$ 401.61
Exercised (in dollars per share)	480.63
Forfeited (in dollars per share)	241.83
Ending balance (in dollars per share)	$ 393.92		$ 401.61
Aggregate Intrinsic Value	$ 45,552		$ 40,986
Weighted Average Remaining Contractual Term	3 years 3 months		3 years 11 months
Vested and exercisable at June 30, 2018
Number of Shares	27,819
Weighted Average Exercise Price (in dollars per share)	$ 402.22
Aggregate Intrinsic Value	$ 45,492
Weighted Average Remaining Contractual Term, Exercisable	3 years 3 months
Vested and exercisable at June 30, 2018 and expected to vest thereafter
Number of Shares	27,892
Weighted Average Exercise Price (in dollars per share)	$ 393.92
Aggregate Intrinsic Value	$ 45,552
Weighted Average Remaining Contractual Term	3 years 3 months
Stock options exercised, total intrinsic value	$ 4,400	$ 16,800
Options, vested, number of shares (in shares)	98	954