Note 3 - Cash and Investments - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash	$ 2,506	$ 6,509
Cash equivalents (see detail in Note 4)	37,023	6,114
Restricted cash	557	337
Total cash, cash equivalents and restricted cash as presented in the consolidated statement of cash flows	$ 40,086	$ 12,960	$ 8,312

Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; including, but not limited to, disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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