XML 88 R51.htm IDEA: XBRL DOCUMENT v3.20.4
Note 9 - Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Net federal and state operating losses $ 159,939 $ 155,190
Research and development credits 66,331 63,275
Royalty income 28,034 0
Stock-based compensation 10,732 9,786
Leasing obligations 1,135 1,070
Other 5,563 3,801
Total deferred tax assets 271,734 233,122
Fixed assets (124) (114)
Right of use asset (854) (803)
Total deferred tax liabilities (978) (917)
Valuation allowance $ (270,756) $ (232,205)