Note 7 - Marketable Securities (Details Textual) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Marketable Securities, Current	$ 5,054	$ 0	$ 4,973
Other-than-temporary Impairment Loss, Debt Securities, Available-for-Sale	$ 0	$ 0

Amount of other-than-temporary impairment (OTTI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), recognized in earnings and other comprehensive loss (OCI).

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 8A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481830/320-10-45-8A

Name:	us-gaap_OtherThanTemporaryImpairmentLossDebtSecuritiesAvailableForSale
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration