Note 1 - Organization and Summary of Significant Accounting Policies - Cash and Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash and cash equivalents	$ 79,314	$ 42,273	$ 123,546
Restricted cash	117	269	424
Total cash, cash equivalents, and restricted cash shown in the statements of cash flows	$ 79,431	$ 42,542	$ 123,970	$ 31,081