Note 2 - Summary of Significant Accounting Policies - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Cash and cash equivalents	$ 35,161	$ 10,640	$ 9,418
Restricted cash included in current assets	891	1,595	2,025
Restricted cash included in long-term assets	270	$ 371	367
Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows	$ 36,322		$ 11,810