CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) [Abstract]
Revenue	$ 4	$ 26	$ 24	$ 302,620
Operating expense:
Licensing costs	0	0	(9,438)	90,101
Research and development	1,151	1,091	3,452	6,799
Selling, general and administrative	3,089	4,270	48,040	38,347
Total operating expense	4,240	5,361	42,054	135,247
Income (loss) from operations	(4,236)	(5,335)	(42,030)	167,373
Gain	0	0	0	41,271
Interest and other income, net	10	17	36	108,272
Income (loss) before taxes	(4,226)	(5,318)	(41,994)	316,916
Income tax (expense) benefit	895	1,293	8,697	(29,036)
Net income (loss)	$ (3,331)	$ (4,025)	$ (33,297)	$ 287,880
Basic income (loss) per share (in dollars per share)	$ (0.05)	$ (0.06)	$ (0.47)	$ 4.07
Diluted income (loss) per share (in dollars per share)	$ (0.05)	$ (0.06)	$ (0.47)	$ 4.02
Weighted average shares outstanding - basic (in shares)	71,233	71,059	71,135	70,780
Weighted average shares outstanding - diluted (in shares)	71,233	71,059	71,135	71,663