XML 46 R35.htm IDEA: XBRL DOCUMENT
v3.24.1.u1

Derivative Financial Instruments (Details) BTU in Billions |  | 1 Months Ended
--- | --- | ---
Mar. 31, 2024 BTU $ / Barrels $ / EnergyContent bbl | May 02, 2024 BTU $ / Barrels $ / EnergyContent bbl
NYMEX Oil Swap Contract Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 0 |
Derivative, Swap Type, Weighted-Average Contract Price | 0 |
NYMEX Oil Swap Contract Third Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 0 |
Derivative, Swap Type, Weighted-Average Contract Price | 0 |
NYMEX Oil Swap Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 780,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 73.24 |
NYMEX Oil Swap Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 323,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 75.00 |
NYMEX Oil Swap Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 0 |
Derivative, Swap Type, Weighted-Average Contract Price | 0 |
NYMEX Oil Collar Contract Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 1,846,000 |
Derivative, Weighted-Average Floor Price | 67.46 |
Derivative, Weighted-Average Ceiling Price | 85.53 |
NYMEX Oil Collar Contract, Third Quarter Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 2,003,000 |
Derivative, Weighted-Average Floor Price | 68.27 |
Derivative, Weighted-Average Ceiling Price | 83.10 |
NYMEX Oil Collar Contract, Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 900,000 |
Derivative, Weighted-Average Floor Price | 69.85 |
Derivative, Weighted-Average Ceiling Price | 78.53 |
NYMEX Oil Collar Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 323,000 |
Derivative, Weighted-Average Floor Price | 68.00 |
Derivative, Weighted-Average Ceiling Price | 79.93 |
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 Contract Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 1,792,000 |
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price | 0.57 |
NYMEX Oil Calendar Month Average Roll Differential Contract Third Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 1,964,000 |
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price | 0.57 |
NYMEX Oil Calendar Month Average Roll Differential Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 1,877,000 |
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price | 0.57 |
NYMEX Oil Calendar Month Average Roll Differential Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 0 |
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price | 0 |
NYMEX Oil Calendar Month Average Roll Differential Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 0 |
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price | 0 |
NYMEX Oil Collar Contract, Years 1 and 2 | Subsequent Event |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 1,000,000.0
Derivative, Weighted-Average Floor Price |  | 71.77
Derivative, Weighted-Average Ceiling Price |  | 82.74
NYMEX Oil Calendar Month Average Roll Differential Contract, Year 1 | Subsequent Event |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl |  | 1,800,000
Derivative, Roll Differential Swap Type, Weighted-Average Contract Price |  | 1.02
WTI Midland NYMEX WTI | Oil Basis Swap Contract Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 1,193,000 |
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | 1.21 |
WTI Midland NYMEX WTI | Oil Basis Swap Contract Third Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 1,235,000 |
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | 1.21 |
WTI Midland NYMEX WTI | Oil Basis Swap Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 1,230,000 |
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | 1.21 |
WTI Midland NYMEX WTI | Oil Basis Swap Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 2,748,000 |
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | 1.15 |
WTI Midland 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 |
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 293,000 |
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | 1.82 |
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract Third Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 332,000 |
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | 1.82 |
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 309,000 |
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | 1.82 |
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 1,413,000 |
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | 1.90 |
WTI Houston MEH NYMEX WTI | Oil Basis Swap Contract, Year 3 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 816,000 |
Derivative, Oil Basis Swap Type, Weighted-Average Contract Price | 2.10 |
NYMEX HH | Gas Swaps Contract Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 4,186 |
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent | 3.17 |
NYMEX HH | Gas Swaps Contract Third Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 2,923 |
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent | 3.18 |
NYMEX HH | Gas Swaps Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 1,569 |
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent | 3.03 |
NYMEX HH | Gas Swaps Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 5,891 |
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent | 4.20 |
NYMEX HH | 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, Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 4,432 |
Derivative, Weighted-Average Floor Price | $ / EnergyContent | 3.69 |
Derivative, Weighted-Average Ceiling Price | $ / EnergyContent | 4.00 |
NYMEX HH | Gas Collar Contract, Third Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 4,612 |
Derivative, Weighted-Average Floor Price | $ / EnergyContent | 3.68 |
Derivative, Weighted-Average Ceiling Price | $ / EnergyContent | 4.21 |
NYMEX HH | Gas Collar Contract, Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 7,328 |
Derivative, Weighted-Average Floor Price | $ / EnergyContent | 3.38 |
Derivative, Weighted-Average Ceiling Price | $ / EnergyContent | 4.97 |
NYMEX HH | Gas Collar Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 25,434 |
Derivative, Weighted-Average Floor Price | $ / EnergyContent | 3.23 |
Derivative, Weighted-Average Ceiling Price | $ / EnergyContent | 4.67 |
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 |
NYMEX HH | Gas Collar Contract, Year 3 | Subsequent Event |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 13,438
Derivative, Weighted-Average Floor Price | $ / EnergyContent |  | 3.25
Derivative, Weighted-Average Ceiling Price | $ / EnergyContent |  | 4.90
IF WAHA NYMEX HH | Gas Basis Swap Contract Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 5,285 |
Derivative, Gas Basis Swap Type, Weighted-Average Contract Price | $ / EnergyContent | (1.09) |
IF WAHA NYMEX HH | Gas Basis Swap Contract Third Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 5,344 |
Derivative, Gas Basis Swap Type, Weighted-Average Contract Price | $ / EnergyContent | (0.99) |
IF WAHA NYMEX HH | Gas Basis Swap Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 5,240 |
Derivative, Gas Basis Swap Type, Weighted-Average Contract Price | $ / EnergyContent | (0.73) |
IF WAHA NYMEX HH | Gas Basis Swap Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 20,501 |
Derivative, Gas Basis Swap Type, Weighted-Average Contract Price | $ / EnergyContent | (0.66) |
IF WAHA 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 |
IF HSC NYMEX HH | Gas Basis Swap Contract Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 3,310 |
Derivative, Gas Basis Swap Type, Weighted-Average Contract Price | $ / EnergyContent | (0.34) |
IF HSC NYMEX HH | Gas Basis Swap Contract Third Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 3,426 |
Derivative, Gas Basis Swap Type, Weighted-Average Contract Price | $ / EnergyContent | (0.30) |
IF HSC NYMEX HH | Gas Basis Swap Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 5,750 |
Derivative, Gas Basis Swap Type, Weighted-Average Contract Price | $ / EnergyContent | (0.38) |
IF HSC NYMEX HH | Gas Basis Swap Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU | 946 |
Derivative, Gas Basis Swap Type, Weighted-Average Contract Price | $ / EnergyContent | 0.0025 |
IF HSC 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 | NGL Swaps Contract Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 387,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 31.90 |
OPIS Propane Mont Belvieu Non-TET | NGL Swaps Contract Third Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 404,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 31.87 |
OPIS Propane Mont Belvieu Non-TET | NGL Swaps Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 434,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 31.85 |
OPIS Propane Mont Belvieu Non-TET | NGL Swaps Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 396,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 32.86 |
OPIS Propane Mont Belvieu Non-TET | NGL Swaps Contract, Year 3 |  |
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 Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 44,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 39.48 |
OPIS Normal Butane Mont Belvieu Non-TET [Member] | NGL Swaps Contract Third Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 46,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 39.48 |
OPIS Normal Butane Mont Belvieu Non-TET [Member] | NGL Swaps Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 49,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 39.48 |
OPIS Normal Butane Mont Belvieu Non-TET [Member] | NGL Swaps Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 45,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 39.48 |
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 |
OPIS Isobutane Mont Belvieu Non-TET | NGL Swaps Contract Second Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 24,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 41.58 |
OPIS Isobutane Mont Belvieu Non-TET | NGL Swaps Contract Third Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 25,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 41.58 |
OPIS Isobutane Mont Belvieu Non-TET | NGL Swaps Contract Fourth Quarter, Year 1 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 28,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 41.58 |
OPIS Isobutane Mont Belvieu Non-TET | NGL Swaps Contract, Year 2 |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Volume | bbl | 25,000 |
Derivative, Swap Type, Weighted-Average Contract Price | 41.58 |
OPIS Isobutane Mont Belvieu Non-TET | 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 | Gas Swaps Contract, Year 3 | Subsequent Event |  |
Derivative Financial Instruments |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | BTU |  | 1,548
Derivative, Swap Type, Weighted-Average Contract Price | $ / EnergyContent |  | 3.26

X
- Definition Derivative, Calendar Month Average Roll Differential Swap Type, Weighted-Average Contract Price + References No definition available. + Details
Name: | sm_DerivativeCalendarMonthAverageRollDifferentialSwapTypeWeightedAverageContractPrice
Namespace Prefix: | sm_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition Derivative, Gas Basis Swap Type, Weighted-Average Contract Price + References No definition available. + Details
Name: | sm_DerivativeGasBasisSwapTypeWeightedAverageContractPrice
Namespace Prefix: | sm_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition Derivative, Oil Basis Swap Type, Weighted-Average Contract Price + References No definition available. + Details
Name: | sm_DerivativeOilBasisSwapTypeWeightedAverageContractPrice
Namespace Prefix: | sm_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cap rate on a price risk derivative such as a cap or collar. A payment or receipt is triggered if the market rate exceeds the cap rate on the contract. + References No definition available. + Details
Name: | us-gaap_DerivativeCapPrice
Namespace Prefix: | us-gaap_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition Floor rate on a price risk derivative such as a floor or a collar. A payment or receipt is triggered if the market rate falls below the floor rate on the contract. + References No definition available. + Details
Name: | us-gaap_DerivativeFloorPrice
Namespace Prefix: | us-gaap_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480237/815-40-50-5 + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal energy measure used to calculate payments on a derivative instrument. + References No definition available. + Details
Name: | us-gaap_DerivativeNonmonetaryNotionalAmountEnergyMeasure
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:energyItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal volume used to calculate payments on a derivative instrument. + References No definition available. + Details
Name: | us-gaap_DerivativeNonmonetaryNotionalAmountVolume
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:volumeItemType
Balance Type: | na
Period Type: | duration

X
- Definition Average fixed price related to the group of price risk swap derivatives. + References No definition available. + Details
Name: | us-gaap_DerivativeSwapTypeAverageFixedPrice
Namespace Prefix: | us-gaap_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilSwapContractSecondQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilSwapContractThirdQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilSwapContractFourthQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilSwapContractYear2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilSwapContractYear3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCollarContractSecondQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCollarContractThirdQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCollarContractFourthQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCollarContractYear2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCollarContractYear3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCalendarMonthAverageRollDifferentialContractSecondQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCalendarMonthAverageRollDifferentialContractThirdQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCalendarMonthAverageRollDifferentialContractFourthQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCalendarMonthAverageRollDifferentialContractYear2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCalendarMonthAverageRollDifferentialContractYear3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCollarContractYears1And2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NYMEXOilCalendarMonthAverageRollDifferentialContractYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeUnderlyingIndexAxis=sm_WTIMidlandNYMEXWTIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_OilBasisSwapContractSecondQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_OilBasisSwapContractThirdQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_OilBasisSwapContractFourthQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_OilBasisSwapContractYear2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_OilBasisSwapContractYear3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeUnderlyingIndexAxis=sm_WTIHoustonMEHNYMEXWTIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeUnderlyingIndexAxis=sm_NYMEXHHMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasSwapsContractSecondQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasSwapsContractThirdQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasSwapsContractFourthQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasSwapsContractYear2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasSwapsContractYear3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasCollarContractSecondQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasCollarContractThirdQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasCollarContractFourthQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasCollarContractYear2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasCollarContractYear3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeUnderlyingIndexAxis=sm_IFWAHANYMEXHHMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasBasisSwapContractSecondQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasBasisSwapContractThirdQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasBasisSwapContractFourthQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasBasisSwapContractYear2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_GasBasisSwapContractYear3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeUnderlyingIndexAxis=sm_IFHSCNYMEXHHMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeUnderlyingIndexAxis=sm_OPISPropaneMontBelvieuNonTETMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NGLSwapsContractSecondQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NGLSwapsContractThirdQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NGLSwapsContractFourthQuarterYear1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NGLSwapsContractYear2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sm_NGLSwapsContractYear3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeUnderlyingIndexAxis=sm_OPISNormalButaneMontBelvieuNonTETMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeUnderlyingIndexAxis=sm_OPISIsobutaneMontBelvieuNonTETMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeUnderlyingIndexAxis=sm_IFWAHAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |