Stockholders' Equity - Schedule of OCI (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Changes in Accumulated Other Comprehensive Income (Loss)
Beginning Balance	$ 2,288,061	$ 680,941
Other comprehensive loss before reclassifications	(1,642)	2,051
Amounts reclassified from accumulated other comprehensive loss	(25)	(125)
Net current period change in accumulated other comprehensive loss, before tax	(1,617)	2,176
Income tax expense related to items of other comprehensive income		520
Ending Balance	2,537,653	776,940
Foreign Currency Translation Adjustments
Changes in Accumulated Other Comprehensive Income (Loss)
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
Changes in Accumulated Other Comprehensive Income (Loss)
Beginning Balance	(75)	(1,397)
Other comprehensive loss before reclassifications	(1,642)	2,051
Amounts reclassified from accumulated other comprehensive loss	0	(125)
Net current period change in accumulated other comprehensive loss, before tax	(1,642)	2,176
Income tax expense related to items of other comprehensive income		520
Ending Balance	(1,717)	259
Accumulated Other Comprehensive Income (Loss)
Changes in Accumulated Other Comprehensive Income (Loss)
Beginning Balance	(100)	(1,422)
Ending Balance	$ (1,717)	$ 234