SEGMENT 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, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment operating profit:	$ 125,274	$ 83,426	$ 232,525	$ 170,935
Stock-based compensation expense	(23,898)	(19,439)	(48,451)	(31,320)
Interest and other income, net	2,580	1,817	7,954	4,203
Foreign exchange loss	(4,693)	(9,167)	(2,394)	(2,643)
Income before provision for income taxes	123,161	76,076	238,085	172,495
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment operating profit:	167,741	111,533	313,896	222,758
Unallocated Amounts
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Stock-based compensation expense	(23,898)	(19,439)	(48,451)	(31,320)
Amortization of intangibles assets	(3,961)	(2,994)	(7,101)	(6,129)
Other acquisition-related expenses	(2,099)	(148)	(4,032)	(616)
Other unallocated expenses	$ (12,509)	$ (5,526)	$ (21,787)	$ (13,758)