SHAREHOLDERS' EQUITY AND SHARE-BASED COMPENSATION (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Number of Options
Outstanding at the beginning of the period (in shares)	2,589,343
Granted (in shares)	137,000	100,000	300,000
Exercised (in shares)	(108,450)
Forfeited (in shares)	(16,001)
Outstanding at the end of the period (in shares)	2,601,892	2,589,343
Exercisable at the end of the period (in shares)	2,279,555
Weighted average exercise price
Outstanding at the beginning of the period (in dollars per share)	$ 18.33
Granted (in dollars per share)	$ 84.61	$ 104.84	$ 69.48
Exercised (in dollars per share)	$ 24.82
Forfeited (in dollars per share)	$ 73.14
Outstanding at the end of the period (in dollars per share)	$ 21.21	$ 18.33
Exercisable at the end of the period (in dollars per share)	$ 13.82
Weighted average contractual term
Weighted average contractual term	4 years 5 months 8 days	5 years 2 months 12 days
Exercisable at the end of the period	3 years 10 months 29 days
Aggregate intrinsic value
Aggregate intrinsic value (in dollars)	$ 47,805	$ 363,293
Exercisable at the end of the period (in dollars)	$ 47,430