ACQUIRED INTANGIBLE ASSETS - Schedule of Acquired Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 201,376	$ 202,326
Accumulated Amortization	(71,580)	(64,714)
Net	$ 129,796	$ 137,612	$ 81,936	$ 69,079
Technology assets
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	5 years	5 years
Cost	$ 119,011	$ 119,508
Accumulated Amortization	(47,372)	(43,084)
Net	$ 71,639	$ 76,424
Customer assets
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	11 years	11 years
Cost	$ 58,375	$ 58,556
Accumulated Amortization	(12,256)	(10,796)
Net	$ 46,119	$ 47,760
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	6 years	6 years
Cost	$ 18,274	$ 18,529
Accumulated Amortization	(8,980)	(8,031)
Net	$ 9,294	$ 10,498
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization period	8 years	8 years
Cost	$ 5,716	$ 5,733
Accumulated Amortization	(2,972)	(2,803)
Net	$ 2,744	$ 2,930