SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Stock-Based Compensation) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Compensation expense	$ 18,138	$ 16,299	$ 54,097	$ 46,988
Cost of revenues
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Compensation expense	3,041	2,835	9,002	8,283
Selling and marketing (excluding customer base amortization)
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Compensation expense	1,957	1,620	5,605	4,644
Software development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Compensation expense	3,158	3,316	9,262	9,289
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Compensation expense	$ 9,982	$ 8,528	$ 30,228	$ 24,772