Note 4 - Fair Value Measurements (Details Textual) $ in Thousands	3 Months Ended
Mar. 31, 2022 USD ($)
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss)	$ 0

Amount of unrealized gain (loss) recognized in income from asset (liability) measured at fair value on recurring basis using unobservable input (level 3) and still held.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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