INTANGIBLE ASSETS AND GOODWILL - Gross Carrying Amount and Accumulated Amortization of Finite-lived Intangible Assets (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 506,088	$ 44,684
Accumulated Amortization	(25,516)	(35,244)
Net Carrying Amount	$ 480,572	9,440
Developed technology
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	3 years 2 months 12 days
Gross Carrying Amount	$ 140,153	39,984
Accumulated Amortization	(12,899)	(34,268)
Net Carrying Amount	$ 127,254	5,716
Content library
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	3 years 9 months 18 days
Gross Carrying Amount	$ 4,700	4,700
Accumulated Amortization	(1,405)	(976)
Net Carrying Amount	$ 3,295	3,724
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	10 years 8 months 12 days
Gross Carrying Amount	$ 295,545	0
Accumulated Amortization	(5,235)	0
Net Carrying Amount	$ 290,310	0
Customer contracts
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	1 year 9 months 18 days
Gross Carrying Amount	$ 58,491	0
Accumulated Amortization	(5,524)	0
Net Carrying Amount	$ 52,967	0
Trade names, trademarks, and domain names
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	2 years 9 months 18 days
Gross Carrying Amount	$ 7,199	0
Accumulated Amortization	(453)	0
Net Carrying Amount	$ 6,746	$ 0