Income Taxes (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Tax Assets and Liabilities
Deferred Tax Assets, Operating Loss Carryforwards	$ 201,610	$ 193,270
Deferred Tax Assets, Tax Credit Carryforwards, Research	29,304	46,306
Deferred Tax Assets, Tax Credit Carryforwards, Orphan Drug	24,524	24,524
Deferred Tax Assets, In Process Research and Development	47,075	58,596
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	5,651	5,340
Deferred Tax Assets, Other	844	5,533
Deferred Tax Assets, Gross	309,008	333,569
Deferred Tax Liability Related to Acquisition of Symphony Icon	0	(4,140)
Deferred Tax Liabilities, Other	0	(3)
Deferred Tax Liabilities, Gross	0	(4,143)
Deferred Tax Assets, Valuation Allowance	(309,008)	(329,426)
Deferred Tax Liabilities, Net	0	0
Income Tax Benefit	0	$ (6,014)	$ 0
2020 Federal NOL increase	38,400
Decrease in NOLs	(66,900)
R&D Tax Credit Decrease	$ 17,000