SEGMENTS INFORMATION (Revenues by Customer Location) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 521,333	$ 424,148
United States
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	299,680	223,683
United Kingdom
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	65,739	51,730
Switzerland
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	36,233	35,604
Netherlands
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	20,616	17,649
Germany
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	19,154	19,488
Canada
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	16,972	15,763
Russia
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	15,892	19,412
Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 47,047	$ 40,819