Note 9 - Leases (Details Textual)	12 Months Ended
Dec. 31, 2023 USD ($) ft²	Dec. 31, 2022 USD ($)	Jan. 19, 2019 USD ($)
Operating Lease, Payments	$ 329,000	$ 319,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset			$ 966,000
Facility Located in Rancho Cordova, California [Member]
Area of Real Estate Property \| ft²	28,000

Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479041/842-20-45-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (g)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147478964/842-20-50-4

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