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Derivative Financial Instruments (Details) bbl in Thousands, BTU in Billions | Oct. 28, 2021 BTU $ / Barrels $ / EnergyContent bbl | Sep. 30, 2021 BTU $ / Barrels $ / EnergyContent bbl
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NYMEX Oil Swap Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 5,052
Derivative, Swap Type, Weighted-Average Contract Price |  | 41.70
NYMEX Oil Swap Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 7,823
Derivative, Swap Type, Weighted-Average Contract Price |  | 44.69
NYMEX Oil Swap Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 1,190
Derivative, Swap Type, Weighted-Average Contract Price |  | 45.20
NYMEX Oil Collar Contract, Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 0
Derivative, Weighted-Average Floor Price |  | 0
Derivative, Weighted-Average Ceiling Price |  | 0
NYMEX Oil Collar Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 2,342
Derivative, Weighted-Average Floor Price |  | 54.00
Derivative, Weighted-Average Ceiling Price |  | 61.39
NYMEX Oil Collar Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 0
Derivative, Weighted-Average Floor Price |  | 0
Derivative, Weighted-Average Ceiling Price |  | 0
NYMEX Oil Calendar Month Average Roll Differential Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 3,831
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price |  | (0.16)
NYMEX Oil Calendar Month Average Roll Differential Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 11,278
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price |  | 0.11
NYMEX Oil Calendar Month Average Roll Differential Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 1,832
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price |  | 0.39
WTI Midland NYMEX WTI [Member] | Oil Basis Swap Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 3,824
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price |  | 0.71
WTI Midland NYMEX WTI [Member] | Oil Basis Swap Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 9,500
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price |  | 1.15
WTI Midland NYMEX WTI [Member] | Oil Basis Swap Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 0
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price |  | 0
NYMEX WTI ICE Brent [Member] | Oil Basis Swap Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 920
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price |  | (7.86)
NYMEX WTI ICE Brent [Member] | Oil Basis Swap Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 3,650
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price |  | (7.78)
NYMEX WTI ICE Brent [Member] | Oil Basis Swap Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 0
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price |  | 0
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 466
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price |  | 0.60
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 1,329
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price |  | 1.25
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 0
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price |  | 0
IF HSC [Member] | Gas Swaps Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 12,412
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 2.41
IF HSC [Member] | Gas Swaps Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 28,932
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 2.52
IF HSC [Member] | Gas Swaps Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 0
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 0
WAHA [Member] | Gas Swaps Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 7,627
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 1.82
WAHA [Member] | Gas Swaps Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 14,087
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 2.32
WAHA [Member] | Gas Swaps Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 0
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 0
IF Tenn TX Z0 | Gas Swaps Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 0
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 0
IF Tenn TX Z0 | Gas Swaps Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 513
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 3.22
IF Tenn TX Z0 | Gas Swaps Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 0
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 0
NYMEX HH | Gas Collar Contract, Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 0
Derivative, Weighted-Average Floor Price | $ / EnergyContent |  | 0
Derivative, Weighted-Average Ceiling Price | $ / EnergyContent |  | 0
NYMEX HH | Gas Collar Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 2,129
Derivative, Weighted-Average Floor Price | $ / EnergyContent |  | 3.40
Derivative, Weighted-Average Ceiling Price | $ / EnergyContent |  | 5.91
NYMEX HH | Gas Collar Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 0
Derivative, Weighted-Average Floor Price | $ / EnergyContent |  | 0
Derivative, Weighted-Average Ceiling Price | $ / EnergyContent |  | 0
IF Tenn TX Z0 NYMEX HH | Gas Basis Swap Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 0
Derivative, Gas Basis Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 0
IF Tenn TX Z0 NYMEX HH | Gas Basis Swap Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 1,254
Derivative, Gas Basis Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 0.04
IF Tenn TX Z0 NYMEX HH | Gas Basis Swap Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 0
Derivative, Gas Basis Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 0
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Swaps Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 917
Derivative, Swap Type, Weighted-Average Contract Price |  | 24.58
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Swaps Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 580
Derivative, Swap Type, Weighted-Average Contract Price |  | 29.71
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Swaps Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 0
Derivative, Swap Type, Weighted-Average Contract Price |  | 0
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Collar Contract, Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 0
Derivative, Weighted-Average Floor Price |  | 0
Derivative, Weighted-Average Ceiling Price |  | 0
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Collar Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 770
Derivative, Weighted-Average Floor Price |  | 25.78
Derivative, Weighted-Average Ceiling Price |  | 31.60
OPIS Propane Mont Belvieu Non-TET [Member] | NGL Collar Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 0
Derivative, Weighted-Average Floor Price |  | 0
Derivative, Weighted-Average Ceiling Price |  | 0
OPIS Normal Butane Mont Belvieu Non-TET [Member] | NGL Swaps Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 36
Derivative, Swap Type, Weighted-Average Contract Price |  | 30.87
OPIS Normal Butane Mont Belvieu Non-TET [Member] | NGL Swaps Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 0
Derivative, Swap Type, Weighted-Average Contract Price |  | 0
OPIS Normal Butane Mont Belvieu Non-TET [Member] | NGL Swaps Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 0
Derivative, Swap Type, Weighted-Average Contract Price |  | 0
IF WAHA [Member] |  |
Derivative Financial Instruments |  |
Index percent of natural gas fixed swaps |  | 81.00%
GD WAHA [Member] |  |
Derivative Financial Instruments |  |
Index percent of natural gas fixed swaps |  | 19.00%
Subsequent Event | NYMEX Oil Collar Contract Third Quarter, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 300 |
Derivative, Weighted-Average Floor Price | 70.00 |
Derivative, Weighted-Average Ceiling Price | 73.52 |
Subsequent Event | NYMEX Oil Collar Contract First Quarter, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 300 |
Derivative, Weighted-Average Floor Price | 60.00 |
Derivative, Weighted-Average Ceiling Price | 75.20 |
Subsequent Event | IF HSC [Member] | Gas Collar Contract, First Quarter, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 900 |
Derivative, Weighted-Average Floor Price | $ / EnergyContent | 3.38 |
Derivative, Weighted-Average Ceiling Price | $ / EnergyContent | 7.75 |

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