Note 5 - Derivative Financial Instruments - Commodity Derivative Contracts (Details) - Not Designated as Hedging Instrument [Member]	12 Months Ended
	Dec. 31, 2021 $ / bbl bbl
Crude Oil Derivative Swap Q1 2022 [Member]
Volume (MBbls) (Barrel of Oil) | bbl	966.4
Price per Bbl (in USD per Barrel of Oil) | $ / bbl	69.26
Crude Oil Derivative Swap Q2 2022 [Member]
Volume (MBbls) (Barrel of Oil) | bbl	794.1
Price per Bbl (in USD per Barrel of Oil) | $ / bbl	69.32
Crude Oil Derivative Swap Q3 2022 [Member]
Volume (MBbls) (Barrel of Oil) | bbl	208.0
Price per Bbl (in USD per Barrel of Oil) | $ / bbl	68.76
Crude Oil Derivative Swap Q4 2022 [Member]
Volume (MBbls) (Barrel of Oil) | bbl	239.0
Price per Bbl (in USD per Barrel of Oil) | $ / bbl	59.37
Crude Oil Derivative Swap 2022 [Member]
Volume (MBbls) (Barrel of Oil) | bbl	2,207.5
Price per Bbl (in USD per Barrel of Oil) | $ / bbl	68.16
Crude Oil Derivative Swap Q1 2023 [Member]
Volume (MBbls) (Barrel of Oil) | bbl	198.0
Price per Bbl (in USD per Barrel of Oil) | $ / bbl	57.22
Crude Oil Derivative Swap Q2 2023 [Member]
Volume (MBbls) (Barrel of Oil) | bbl	200.2
Price per Bbl (in USD per Barrel of Oil) | $ / bbl	57.22
Crude Oil Derivative Swap 2023 [Member]
Volume (MBbls) (Barrel of Oil) | bbl	398.2
Price per Bbl (in USD per Barrel of Oil) | $ / bbl	57.22