Note 10 - Fair Value Measurement - Cash and Cash Equivalents (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Total assets	$ 4,968	$ 65,233	$ 25,039
Interest rate swap		3,514	5,770
Total liabilities		3,514	5,770
Commodity Contract [Member]
Commodity swap	2,524		1,550
Fair Value, Inputs, Level 1 [Member]
Total assets	2,444	65,233	23,489
Interest rate swap		0	0
Total liabilities		0	0
Fair Value, Inputs, Level 1 [Member] \| Commodity Contract [Member]
Commodity swap	0		0
Fair Value, Inputs, Level 2 [Member]
Total assets	2,524	0	1,550
Interest rate swap		3,514	5,770
Total liabilities		3,514	5,770
Fair Value, Inputs, Level 2 [Member] \| Commodity Contract [Member]
Commodity swap	2,524		1,550
Fair Value, Inputs, Level 3 [Member]
Total assets	0	0	0
Interest rate swap		0	0
Total liabilities		0	0
Fair Value, Inputs, Level 3 [Member] \| Commodity Contract [Member]
Commodity swap	0		0
Money Market Funds [Member]
Cash equivalents	2,444	65,233	23,489
Money Market Funds [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash equivalents	2,444	65,233	23,489
Money Market Funds [Member] \| Fair Value, Inputs, Level 2 [Member]
Cash equivalents	0	0	0
Money Market Funds [Member] \| Fair Value, Inputs, Level 3 [Member]
Cash equivalents	$ 0	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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- Definition

Fair value of all liability derivatives designated as cash flow hedging instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959

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- Definition

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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Fair value of financial and nonfinancial obligations.

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