STOCK BASED COMPENSATION - Outstanding and Exercisable Options (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted average remaining contractual life of outstanding options	6 years 1 month 6 days	6 years 7 months 6 days	6 years 8 months 12 days
Total aggregate intrinsic value of outstanding options	$ 269,900	$ 254,200	$ 175,200
Weighted average remaining contractual life of exercisable options	5 years 1 month 6 days	5 years 3 months 18 days	5 years 6 months
Total aggregate intrinsic value of exercisable options	$ 178,300	$ 161,100	$ 114,500