Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating costs and expenses:
Selling, general and administrative	$ 9,870	$ 14,315
Research and development	4,193	19,371
Total operating costs and expenses	14,063	33,686
Loss from continuing operations before other income (expense) and income taxes	(14,063)	(33,686)
Other income (expense):
Interest income, net	11	84
Other expense, net	(1,334)	(2,081)
Total other expense	(1,323)	(1,997)
Loss from continuing operations before income taxes	(15,386)	(35,683)
Benefit for income taxes from continuing operations	(16)	7
Loss from continuing operations	(15,402)	(35,676)
Loss from discontinued operations, net of income taxes	(40)	(21)
Net loss	$ (15,442)	$ (35,697)
Basic and diluted loss per share:
Loss from continuing operations, basic (in dollars per shares)	$ (0.09)	$ (0.25)
Loss from continuing operations, diluted (in dollars per shares)	(0.09)	(0.25)
Loss from discontinued operations, basic (in dollars per shares)	(0.00)	(0.00)
Loss from discontinued operations, diluted (in dollars per shares)	(0.00)	(0.00)
Net loss per share, basic (in dollars per shares)	(0.09)	(0.25)
Net loss per share, diluted (in dollars per shares)	$ (0.09)	$ (0.25)
Weighted average shares outstanding, basic (in shares)	169,735,019	145,371,657
Weighted average shares outstanding, diluted (in shares)	169,735,019	145,371,657