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Note 13 - Fair Value Measurements - Financial Assets and Liabilities Measured on a Recurring Basis at Fair Value (Details) - USD ($) $ in Thousands | Sep. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Derivate liabilities |  | $ 4,190
Fuel Hedge [Member] |  |
Derivate liabilities |  | 297
Fuel hedge | $ 82 |
Interest Rate Swap [Member] |  |
Derivate liabilities | 1,563 | 3,893
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Derivate liabilities |  | 0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Fuel Hedge [Member] |  |
Derivate liabilities |  | 0
Fuel hedge | 0 |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Interest Rate Swap [Member] |  |
Derivate liabilities | 0 | 0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Derivate liabilities |  | 0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Fuel Hedge [Member] |  |
Derivate liabilities |  | 0
Fuel hedge | 0 |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member] |  |
Derivate liabilities | 0 | 0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Derivate liabilities |  | 4,190
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Fuel Hedge [Member] |  |
Derivate liabilities |  | 297
Fuel hedge | 82 |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest Rate Swap [Member] |  |
Derivate liabilities | $ 1,563 | $ 3,893

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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. 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 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
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