STOCKHOLDERS' EQUITY - Schedule of OCI (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 2,288,061	$ 680,941
Other comprehensive loss before reclassifications	1,159	815
Amounts reclassified from accumulated other comprehensive loss	25	616
Net current period change in accumulated other comprehensive loss, before tax	1,184	1,431
Income tax expense related to items of other comprehensive income		(341)
Ending Balance	2,337,100	748,284
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(25)	(25)
Other comprehensive loss before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive loss	25	0
Net current period change in accumulated other comprehensive loss, before tax	25	0
Income tax expense related to items of other comprehensive income		0
Ending Balance	0	(25)
Unrealized Gain (Loss) on Marketable Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(75)	(1,397)
Other comprehensive loss before reclassifications	1,159	815
Amounts reclassified from accumulated other comprehensive loss	0	616
Net current period change in accumulated other comprehensive loss, before tax	1,159	1,431
Income tax expense related to items of other comprehensive income		(341)
Ending Balance	1,084	(307)
Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(100)	(1,422)
Ending Balance	$ 1,084	$ (332)