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Note 15 - Fair Value Measurements (Details Textual) gal in Millions, $ in Millions | 12 Months Ended
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Dec. 31, 2020 USD ($) $ / gal gal
Interest Rate Swap [Member] |
Derivative, Number of Instruments Held, Total | 2
Interest Rate Swap, One [Member] |
Derivative, Notional Amount | $ | $ 53
Interest Rate Swap, Two [Member] |
Derivative, Notional Amount | $ | $ 68
Fuel Hedge [Member] |
Derivative, Nonmonetary Notional Amount, Volume (Gallon) | gal | 1
Fuel Hedge [Member] | Minimum [Member] |
Underlying, Derivative Volume (in USD per Gallon) | $ / gal | 1.79
Fuel Hedge [Member] | Maximum [Member] |
Underlying, Derivative Volume (in USD per Gallon) | $ / gal | 2.00

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