Note 5 - Revenue - Changes in Contract Liabilities (Details) $ in Thousands	6 Months Ended
Jun. 30, 2022 USD ($)
Balance	$ 1,062
Non-cancelable contracts with customers entered into during the period	0
Revenue recognized related to non-cancelable contracts with customers during the period	(1,062)
Balance	$ 0

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

Reference 1: 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 2: 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 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=126919976&loc=SL49130532-203044

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