SEGMENTS INFORMATION (Reconciliation of Segment Operating Profit to Consolidated Income Before Provision for Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment operating profit	$ 83,426	$ 72,882	$ 170,935	$ 137,540
Stock-based compensation expense			31,320	37,553
Interest and other income, net	1,817	1,190	4,203	4,266
Foreign exchange loss	(9,167)	(3,562)	(2,643)	(7,046)
Income before provision for income taxes	76,076	70,510	172,495	134,760
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment operating profit	111,533	102,678	222,758	199,509
Unallocated Amounts
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Stock-based compensation expense	(19,439)	(15,697)	(31,320)	(37,553)
Amortization of intangibles assets	(2,994)	(2,601)	(6,129)	(4,739)
Other acquisition-related expenses	(148)	(850)	(616)	(1,361)
Other unallocated expenses	$ (5,526)	$ (10,648)	$ (13,758)	$ (18,316)