Amount of increase (decrease) in obligation for operating lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (g)(1)
-SubTopic 20
-Topic 842
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147478964/842-20-50-4

+ Details

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

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147478964/842-20-50-3

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of lessee's right to use underlying asset under operating lease.

+ References

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

+ Details

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

- Definition

Amount of periodic reduction over lease term of carrying amount of right-of-use asset from operating lease.

+ References

+ Details

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

- Details

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Namespace Prefix:
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- Details

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Note 8 - Leases (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Note 8 - Leases (Details Textual) - USD ($) $ in Thousands	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Operating Lease, Right-of-Use Asset, Periodic Reduction	$ 391	$ 329	$ 782	$ 638
Operating Lease, Right-of-Use Asset	$ 5,177		5,177		$ 5,770
Increase (Decrease) in Operating Lease Liability			$ (849)	$ (701)
Environmental Technologies in Germany [Member]
Lessee, Operating Lease, Term of Contract (Month)	25 months		25 months
Operating Lease, Right-of-Use Asset	$ 90		$ 90
Increase (Decrease) in Operating Lease Liability			$ 90
Process Technologies [Member] \| Automobile Lease, One [Member]
Lessee, Operating Lease, Term of Contract (Month)	36 months		36 months
Process Technologies [Member] \| Automobile Lease, Two [Member]
Lessee, Operating Lease, Term of Contract (Month)	48 months		48 months
Process Technologies [Member] \| Automobile Leases [Member]
Operating Lease, Right-of-Use Asset	$ 71		$ 71
Increase (Decrease) in Operating Lease Liability			$ 71