EQUITY AND SHARE-BASED COMPENSATION (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Number of Options
Outstanding at the beginning of the period (in shares)	3,058,309
Granted (in shares)	75,000	300,000
Exercised (in shares)	(279,531)
Forfeited (in shares)	(117,248)
Outstanding at the end of the period (in shares)	2,736,530		3,058,309
Exercisable at the end of the period (in shares)	2,216,347
Weighted average exercise price
Outstanding at the beginning of the period (in dollars per share)	$ 17.69
Granted (in dollars per share)	$ 104.84	$ 69.48
Exercised (in dollars per share)	$ 17.12
Forfeited (in dollars per share)	$ 59.49
Outstanding at the end of the period (in dollars per share)	$ 18.34		$ 17.69
Exercisable at the end of the period (in dollars per share)	$ 11.99
Weighted average contractual term
Weighted average contractual term	5 years 4 months 24 days		6 years 1 month 6 days
Exercisable at the end of the period	4 years 10 months 24 days
Aggregate intrinsic value
Aggregate intrinsic value (in dollars)	$ 332,955		$ 211,072
Exercisable at the end of the period (in dollars)	$ 283,735