Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Restricted Cash and Cash Equivalents, Total	$ 2,392
Restricted Cash and Cash Equivalents, Current, Total	2,025	$ 2,080	$ 988
Restricted Cash and Cash Equivalents, Noncurrent, Total	$ 367	$ 507	$ 1,494