LEASES (Lease Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Lessee, Lease, Description [Line Items]
Total operating lease costs	$ 8,515	$ 6,974	$ 24,478	$ 20,955
Cost of Revenues [Member]
Lessee, Lease, Description [Line Items]
Total operating lease costs	2,992	2,690	8,732	9,080
Software Development [Member]
Lessee, Lease, Description [Line Items]
Total operating lease costs	1,628	1,091	4,412	3,070
Selling and Marketing [Member]
Lessee, Lease, Description [Line Items]
Total operating lease costs	2,636	2,198	7,725	6,568
General and Administrative [Member]
Lessee, Lease, Description [Line Items]
Total operating lease costs	$ 1,259	$ 995	$ 3,609	$ 2,237