Note 1 - Organization and Significant Accounting Policies - Excess and Obsolete Inventory Reserve (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Excess and obsolete inventory reserve, beginning balance	$ 927	$ 907
Provision charged to expense	0	0
Write-offs / Recoveries	0	20
Excess and obsolete inventory reserve, ending balance	$ 927	$ 927

Amount of valuation reserve for inventory.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(6))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.BB)
-URI https://asc.fasb.org/extlink&oid=27011343&loc=d3e100047-122729

Name:	us-gaap_InventoryValuationReserves
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant