Note 8 - Paycheck Protection Program Loan (Details Textual) - USD ($)		12 Months Ended
Apr. 24, 2020	Dec. 31, 2020	Dec. 31, 2019
Proceeds from Issuance of Unsecured Debt		$ 1,343,000
Paycheck Protection Program CARES Act [Member]
Proceeds from Issuance of Unsecured Debt	$ 1,343,000

The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585

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