REVENUE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues [Abstract]
Service Revenue	$ 940,920	$ 938,679	$ 662,059
Reimbursement Revenue	107,344	137,634	102,478
Non-controlling interests’ Revenue	3,202	2,603	3,820
Revenue	$ 1,051,466	$ 1,078,916	$ 768,357