STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment
Beginning Balance at Dec. 31, 2018	$ (20,465)		$ 11	$ 3,052	$ (23,528)
Beginning Balance, Shares at Dec. 31, 2018			1,070
Contributions from PDL	3,928			3,928
Distributions to PDL	(143)			(143)
Settlement of phantom stock-based awards	784			784
Net loss	(14,657)				(14,657)
Ending Balance at Dec. 31, 2019	$ (30,553)	$ (34)	$ 11	7,621	(38,185)	$ (34)
Ending Balance, Shares at Dec. 31, 2019			1,070
Accounting Standards Update Extensible List	us-gaap:AccountingStandardsUpdate201613Member
Impact from recapitalization transactions	$ 69,879		$ 62	69,817
Impact from recapitalization transactions, Shares			6,221
Sale of common stock to PDL	16,431		$ 15	16,416
Sale of common stock to PDL, Shares			1,496
Capital contribution from PDL	20,666			20,666
Issuance of common stock, net of cancellations			$ 21	(21)
Issuance of common stock, net of cancellations,Shares			2,146
Stock-based compensation under the 2020 Plan	8,849			8,849
Contributions from PDL	2,518			2,518
Distributions to PDL	(1,861)			(1,861)
Settlement of phantom stock-based awards	783			783
Modification of phantom stock-based awards	306			306
Net loss	(19,774)				(19,774)
Ending Balance at Dec. 31, 2020	$ 67,210		$ 109	$ 125,094	$ (57,993)
Ending Balance, Shares at Dec. 31, 2020			10,933