FAIR VALUE MEASUREMENTS (Details) (Fair Value, Measurements, Recurring, USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	$ 35,348	$ 37,400
Performance-based equity awards	5,446	3,223
Total liabilities measured at fair value on a recurring basis	40,794	40,623
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	35,348	37,400
Performance-based equity awards	5,446	3,223
Total liabilities measured at fair value on a recurring basis	$ 40,794	$ 40,623