Income Taxes (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred Tax Assets and Liabilities
Deferred Tax Assets, Operating Loss Carryforwards	$ 251,331	$ 229,427
Deferred Tax Assets, Tax Credit Carryforwards, Research	29,290	29,290
Deferred Tax Assets, Tax Credit Carryforwards, Orphan Drug	24,524	24,524
Deferred Tax Assets, In Process Research and Development	33,813	36,770
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	5,445	5,163
Deferred Tax Assets, Other	2,255	1,308
Deferred Tax Assets, Gross	347,056	326,630
Deferred Tax Liabilities, Other	(1,295)	(412)
Deferred Tax Liabilities, Gross	(1,295)	(412)
Deferred Tax Assets, Valuation Allowance	(345,761)	(326,218)
Deferred Tax Liabilities, Net	0	0
Income Tax Benefit	0	0	$ 0
2020 Federal NOL increase	104,000
Deferred Tax Assets, Section 163j_LXRX	398	$ 148
Operating Loss Carryforwards, Federal	1,200,000
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	$ 446,300