FAIR VALUE MEASUREMENTS FAIR VALUE MEASUREMENTS (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 19, 2017	Jun. 14, 2017	May 31, 2017	Nov. 16, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Annual interest rate on convertible senior notes							0.625%
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at December 31, 2016			$ 23,100,000
Change in fair value of contingent consideration	$ 2,501,000	$ 0	20,640,000	$ 0
Contingent consideration additions			11,318,000
Contingent consideration payments			(1,000,000)
Balance at September 30, 2017	$ 54,058,000		$ 54,058,000
Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration					$ 0	$ 0		$ 0
Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration					$ 9,000,000	$ 9,000,000		$ 45,000,000