Note 13 - Income Taxes (Details Textual)

v3.22.1

Note 13 - Income Taxes (Details Textual) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Unrecognized Tax Benefits, Ending Balance	$ 0	$ 0
Domestic Tax Authority [Member] \| Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards, Total	164,100	$ 164,000
Domestic Tax Authority [Member] \| Internal Revenue Service (IRS) [Member] \| Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	9,100
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	$ 20,100

- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32559-109319

+ Details

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

- Definition

The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

+ Details

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

- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 10B
-URI https://asc.fasb.org/extlink&oid=123427490&loc=SL37586934-109318

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=121826272&loc=SL6600010-109319

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Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:
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Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxCreditCarryforwardAxis=us-gaap_ResearchMember
Namespace Prefix:
Data Type:	na
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- Details

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Quarterly report pursuant to Section 13 or 15(d)

Note 13 - Income Taxes (Details Textual)