STOCK-BASED EMPLOYEE COMPENSATION (Stock Options) (Details) - Employee Stock Option [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Number of Shares
Beginning balance (in shares)	30,675
Exercised (in shares)	(2,416)
Forfeited (in shares)	(11)
Ending balance (in shares)	28,248.000		30,675
Weighted-Average Exercise Price
Beginning balance (in dollars per share)	$ 401.61
Exercised (in dollars per share)	477.21
Forfeited (in dollars per share)	66.98
Ending balance (in dollars per share)	$ 395.35		$ 401.61
Aggregate Intrinsic Value	$ 47,599		$ 40,986
Weighted Average Remaining Contractual Term	3 years 7 months		3 years 11 months
Vested and exercisable as of March 31, 2018
Number of Shares	28,160
Weighted Average Exercise Price (in dollars per share)	$ 403.59
Aggregate Intrinsic Value	$ 47,509
Weighted Average Remaining Contractual Term, Exercisable	3 years 7 months
Vested and exercisable as of March 31, 2018 and expected to vest thereafter
Number of Shares	28,248
Weighted Average Exercise Price (in dollars per share)	$ 395.35
Aggregate Intrinsic Value	$ 47,599
Weighted Average Remaining Contractual Term	3 years 7 months
Stock options exercised, total intrinsic value	$ 3,900	$ 5,400
Options, vested, number of shares (in shares)	83	539