ACQUISITIONS ASSETS ACQUIRED (TABLES) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Apr. 30, 2018
Business Acquisition [Line Items]
Total deferred tax assets, net	$ 12,103	$ 15,523
Goodwill	203,823	204,633
Accrued employee compensation and benefits	$ 111,430	$ 83,437
SCS
Business Acquisition [Line Items]
Cash			$ 4,530
Accounts receivable.			985
Prepaid Expenses			39
Goodwill			1,231
Total assets acquired			10,404
Accounts payable			216
Accrued employee compensation and benefits			27
Accrued expenses			21
Deferred tax liabilities			629
Total liabilities assumed			893
Total purchase price			9,511
SCS | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets			$ 3,619