EQUITY AND SHARE-BASED COMPENSATION (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Number of Options
Outstanding at the beginning of the period (in shares)	2,601,892
Granted (in shares)	30,000	0
Exercised (in shares)	(21,984)
Forfeited (in shares)	(23,000)
Outstanding at the end of the period (in shares)	2,586,908		2,601,892
Exercisable at the end of the period (in shares)	2,264,976
Weighted average exercise price
Outstanding at the beginning of the period (in usd per share)	$ 21.21
Granted (in usd per share)	$ 26.42
Exercised (in usd per share)	$ 9.19
Forfeited (in usd per share)	$ 51.92
Outstanding at the end of the period (in usd per share)	$ 21.10		$ 21.21
Exercisable at the end of the period (in usd per share)	$ 13.73
Weighted average contractual term
Weighted average contractual term, beginning balance	4 years 3 months 7 days		4 years 5 months 9 days
Weighted average contractual term, ending balance	4 years 3 months 7 days		4 years 5 months 9 days
Exercisable at the end of the period	3 years 8 months 19 days
Aggregate intrinsic value
Aggregate intrinsic value, beginning balance (in dollars)	$ 47,805
Aggregate intrinsic value, ending balance (in dollars)	6,143		47,805
Exercisable at the end of the period (in dollars)	$ 6,143