Note 3 - Fair Value Measurements (Details Textual) $ in Thousands	3 Months Ended
Mar. 31, 2022 USD ($)
Marketable Securities, Unrealized Gain (Loss)	$ 23

Amount of unrealized gain (loss) on investment in marketable security.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration