COMMITMENTS AND CONTINGENCIES (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies [Line Items]
Operating lease expense			$ 20,065	$ 18,200	$ 15,664
Breach of Contract Against IDEAB
Commitments and Contingencies [Line Items]
Legal settlement amount	$ 1,000
Construction in Progress
Commitments and Contingencies [Line Items]
Capitalized construction costs		$ 22,714