Note 2 - Revenue and Product Costs (Details Textual) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Contract with Customer, Liability, Total	$ 300	$ 265
Contract with Customer, Asset, after Allowance for Credit Loss, Total	0	0
Virtual Reality Training [Member]
Contract with Customer, Liability, Total	177	172
Extended Product Warranties [Member]
Contract with Customer, Liability, Total	$ 123	$ 67

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126920106&loc=SL49130549-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=126919976&loc=SL49130531-203044

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=126919976&loc=SL49130533-203044

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant