SEGMENT REPORTING (Details) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Sep. 30, 2021 USD ($) operating_segment	Sep. 30, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of business segments | operating_segment							2
Reconciliation of EBITDA to net income (loss) [Abstract]
Net income	$ 64,304	$ 61,148	$ 74,212	$ 58,186	$ 60,360	$ 72,793	$ 199,664	$ 191,339
Amortization of acquired intangible assets in cost of revenues	7,209			6,612			21,565	18,671
Amortization of acquired intangible assets in operating expenses	19,121			18,258			55,885	44,677
Depreciation and other amortization	6,610			6,806			22,138	20,563
Interest expense, net	7,943			7,537			23,698	9,482
Other (income) expense	(1,546)			338			(2,343)	(29)
Income tax expense	19,031			10,748			70,933	33,200
EBITDA	122,672			108,485			391,540	317,903
North America
Reconciliation of EBITDA to net income (loss) [Abstract]
EBITDA	119,823			107,906			385,857	322,611
International
Reconciliation of EBITDA to net income (loss) [Abstract]
EBITDA	$ 2,849			$ 579			$ 5,683	$ (4,708)