CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Common Stock and Additional Paid-in Capital [Member]	Accumulated Deficit (Retained Earnings) [Member]	Accumulated Other Comprehensive Loss [Member]	Total
Balance at Dec. 31, 2019	$ 223,244	$ (217,602)	$ (14)	$ 5,628
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued for cash, net	4,488
Common stock issued for options/RSUs, net	768
Stock-based compensation	778
Net (loss) income		299,945		299,945
Change in unrealized investment gain/loss, net			2	2
Change in foreign currency translation, net			1	1
Balance at Mar. 31, 2020	229,278	82,343	(11)	311,610
Balance at Dec. 31, 2020	232,464	(8,014)	(13)	224,437
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued for cash, net	0
Common stock issued for options/RSUs, net	0
Stock-based compensation	879
Net (loss) income		(26,443)		(26,443)
Change in unrealized investment gain/loss, net			5	5
Change in foreign currency translation, net			(3)	(3)
Balance at Mar. 31, 2021	$ 233,343	$ (34,457)	$ (11)	$ 198,875