Note 4 - Stock-Based Compensation - Weighted Average Period for Recognition of Unrecognized Compensation Cost for Stock Options and Restricted Stock (Details)	12 Months Ended
Dec. 31, 2022
Restricted Stock [Member]
Weighted average period (in years) (Year)	1 year 18 days
Restricted Stock Units (RSUs) [Member]
Weighted average period (in years) (Year)	1 year 9 months 29 days
Performance Shares [Member]
Weighted average period (in years) (Year)	1 year 10 months 17 days

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration