ACQUIRED INTANGIBLE ASSETS - Schedule of Acquired Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 131,508	$ 114,499
Accumulated Amortization	(49,572)	(45,420)
Net	81,936	69,079	$ 79,697	$ 77,102
Technology assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	70,081	53,900
Accumulated Amortization	(34,193)	(31,873)
Net	$ 35,888	$ 22,027
Amortization period	5 years	5 years
Customer assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 44,000	$ 44,000
Accumulated Amortization	(7,824)	(6,934)
Net	$ 36,176	$ 37,066
Amortization period	12 years	12 years
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 12,128	$ 11,300
Accumulated Amortization	(5,248)	(4,473)
Net	$ 6,880	$ 6,827
Amortization period	4 years	4 years
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 5,299	$ 5,299
Accumulated Amortization	(2,307)	(2,140)
Net	$ 2,992	$ 3,159