Note 18 - Commitments and Contingencies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Unrecorded Unconditional Purchase Obligation	$ 144,400
Restricted Cash, Current	7,936	$ 7,815	$ 3,957
BP Energy Company, Preferred Supplier Agreement [Member]
Restricted Cash, Current	800
Accounts Payable, Trade	33,500
BP Energy Company, Preferred Supplier Agreement [Member] \| Asset Pledged as Collateral [Member]
Accounts Receivable, after Allowance for Credit Loss	76,100
Surety Bond [Member]
Guarantor Obligations, Current Carrying Value	28,400
Financial Standby Letter of Credit [Member] \| Unused lines of Credit [Member]
Guarantor Obligations, Current Carrying Value	1,000
Electricity [Member]
Unrecorded Unconditional Purchase Obligation	140,700
Unrecorded Unconditional Purchase Obligation, Purchases	88,800	39,400	39,000
Renewable Energy Credits [Member]
Unrecorded Unconditional Purchase Obligation	3,700
Unrecorded Unconditional Purchase Obligation, Purchases	$ 10,300	$ 16,800	$ 19,500

Carrying value as of the balance sheet date of obligations incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

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The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of cash restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Amount of unrecorded obligation to transfer funds in future for fixed or minimum amount or quantity of product and service at fixed or minimum price. Includes, but is not limited to, lease not yet commenced and take-or-pay and throughput contracts.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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The amount purchased during the period under an unrecorded unconditional purchase obligation (for example, under the take-or-pay or throughput contract).

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