STOCKHOLDERS' EQUITY - Schedule of OCI (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 2,288,061	$ 680,941
Other comprehensive loss before reclassifications	1,564	3,784
Amounts reclassified from accumulated other comprehensive loss	25	344
Net current period change in accumulated other comprehensive loss, before tax	1,589	4,128
Income tax expense related to items of other comprehensive income		(984)
Ending Balance	2,511,193	765,532
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	1,564	3,784
Amounts reclassified from accumulated other comprehensive loss	0	344
Net current period change in accumulated other comprehensive loss, before tax	1,564	4,128
Income tax expense related to items of other comprehensive income		(984)
Ending Balance	1,489	1,747
Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(100)	(1,422)
Ending Balance	$ 1,489	$ 1,722