Note 13 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Research & Experimental and Orphan Drug tax credit carry-forwards	$ 38,180	$ 35,435
NYS investment tax credit carry-forwards	929	1,282
Net operation loss carry-forwards	200,738	188,588
Capitalized research and development expenditures		1,066
Stock compensation	5,365	5,236
Section 163j disallowed interest	1,243	695
Lease liability	3,380
Other items	743	124
Total gross deferred tax assets	250,578	232,426
Less valuation allowance	(246,297)	(232,174)
Deferred tax assets	4,281	252
Indefinite-lived intangibles	(195)	(136)
Right-of-use lease asset	(2,964)
Depreciation and amortization	(1,156)	(144)
Deferred tax liabilities	(4,315)	(280)
Net deferred tax liability	$ (34)	$ (28)