Note 2 - Fair Value Measurements - Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Derivative asset - current	$ 25,097	$ 8,860
Derivative asset	4,727	770
Derivative liability - current	1,040	6,889
Derivative liability	577	0
Fair Value, Recurring [Member]
Derivative asset - current	25,097	8,860
Derivative asset	4,727	770
Total financial assets	29,824	9,630
Derivative liability - current	1,040	6,889
Derivative liability	577	0
Total financial liabilities	1,617	6,889
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Derivative asset - current	0	0
Derivative asset	0	0
Total financial assets	0	0
Derivative liability - current	0	0
Derivative liability	0	0
Total financial liabilities	0	0
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Derivative asset - current	25,097	8,860
Derivative asset	4,727	770
Total financial assets	29,824	9,630
Derivative liability - current	1,040	6,889
Derivative liability	577	0
Total financial liabilities	1,617	6,889
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Derivative asset - current	0	0
Derivative asset	0	0
Total financial assets	0	0
Derivative liability - current	0	0
Derivative liability	0	0
Total financial liabilities	$ 0	$ 0

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.

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