XML 44 R56.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Derivative Financial Instruments (Details) | Dec. 31, 2014 bbl
--- | ---
Crude Oil [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 14,700,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember
Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 230,800,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember
Natural Gas Liquids [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 781,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasLiquidsReservesMember
IF El Paso Permian [Member] |
Derivative Financial Instruments |
Index percent of natural gas fixed swaps | 3.00%sm_IndexPercentOfNaturalGasFixedSwaps / us-gaap_DerivativeByNatureAxis = sm_IfElPasoPermianMember
Index percent of natural gas collars | 4.00%sm_IndexPercentOfNaturalGasCollars / us-gaap_DerivativeByNatureAxis = sm_IfElPasoPermianMember
IF HSC [Member] |
Derivative Financial Instruments |
Index percent of natural gas fixed swaps | 82.00%sm_IndexPercentOfNaturalGasFixedSwaps / us-gaap_DerivativeByNatureAxis = sm_IfHscMember
Index percent of natural gas collars | 80.00%sm_IndexPercentOfNaturalGasCollars / us-gaap_DerivativeByNatureAxis = sm_IfHscMember
IF NGPL TXOK [Member] |
Derivative Financial Instruments |
Index percent of natural gas fixed swaps | 1.00%sm_IndexPercentOfNaturalGasFixedSwaps / us-gaap_DerivativeByNatureAxis = sm_IfNgplTxokMember
IF NNG Ventura [Member] |
Derivative Financial Instruments |
Index percent of natural gas fixed swaps | 3.00%sm_IndexPercentOfNaturalGasFixedSwaps / us-gaap_DerivativeByNatureAxis = sm_IfNngVenturaMember
Index percent of natural gas collars | 8.00%sm_IndexPercentOfNaturalGasCollars / us-gaap_DerivativeByNatureAxis = sm_IfNngVenturaMember
IF Enable East [Member] |
Derivative Financial Instruments |
Index percent of natural gas fixed swaps | 11.00%sm_IndexPercentOfNaturalGasFixedSwaps / us-gaap_DerivativeByNatureAxis = sm_IFEnableEastMember
Index percent of natural gas collars | 8.00%sm_IndexPercentOfNaturalGasCollars / us-gaap_DerivativeByNatureAxis = sm_IFEnableEastMember
OPIS Natural Gasoline Mt Belv Non TET [Member] |
Derivative Financial Instruments |
Index percent of NGL fixed swaps | 28.00%sm_IndexPercentOfNglFixedSwaps / us-gaap_DerivativeByNatureAxis = sm_OPISNaturalGasolineMtBelvNonTETMember
OPIS Propane Mt Belv TET [Member] |
Derivative Financial Instruments |
Index percent of NGL fixed swaps | 72.00%sm_IndexPercentOfNglFixedSwaps / us-gaap_DerivativeByNatureAxis = sm_OPISPropaneMtBelvTETMember
Swap [Member] | Crude Oil [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 11,311,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Swap [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 217,763,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Swap [Member] | Natural Gas Liquids [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 781,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasLiquidsReservesMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Collar [Member] | Crude Oil [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 3,366,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Collar [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 13,002,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
First Quarter of 2015 [Member] | Swap [Member] | Crude Oil [Member] |
Derivative Financial Instruments |
Weighted- Average Contract Price | 91.96 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Portion of Future Oil and Gas Production Being Hedged | 1,711,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
First Quarter of 2015 [Member] | Swap [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 23,548,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Weighted- Average Contract Price | 4.22 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
First Quarter of 2015 [Member] | Swap [Member] | Natural Gas Liquids [Member] |
Derivative Financial Instruments |
Weighted- Average Contract Price | 55.42 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasLiquidsReservesMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Portion of Future Oil and Gas Production Being Hedged | 781,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasLiquidsReservesMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
First Quarter of 2015 [Member] | Collar [Member] | Crude Oil [Member] |
Derivative Financial Instruments |
Weighted- Average Floor Price | 85.00 us-gaap_DerivativeAverageFloorPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Ceiling Price | 99.53 us-gaap_DerivativeAverageCapPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Portion of Future Oil and Gas Production Being Hedged | 882,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
First Quarter of 2015 [Member] | Collar [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 2,524,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Floor Price | 4.00 us-gaap_DerivativeAverageFloorPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Ceiling Price | 4.30 us-gaap_DerivativeAverageCapPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_FirstQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Second Quarter of 2015 [Member] | Swap [Member] | Crude Oil [Member] |
Derivative Financial Instruments |
Weighted- Average Contract Price | 91.26 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_SecondQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Portion of Future Oil and Gas Production Being Hedged | 1,639,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_SecondQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Second Quarter of 2015 [Member] | Swap [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 15,985,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_SecondQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Weighted- Average Contract Price | 3.90 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_SecondQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Second Quarter of 2015 [Member] | Collar [Member] | Crude Oil [Member] |
Derivative Financial Instruments |
Weighted- Average Floor Price | 85.00 us-gaap_DerivativeAverageFloorPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_SecondQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Ceiling Price | 94.06 us-gaap_DerivativeAverageCapPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_SecondQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Portion of Future Oil and Gas Production Being Hedged | 709,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_SecondQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Second Quarter of 2015 [Member] | Collar [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 2,297,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_SecondQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Floor Price | 4.00 us-gaap_DerivativeAverageFloorPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_SecondQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Ceiling Price | 4.30 us-gaap_DerivativeAverageCapPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_SecondQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Third Quarter of 2015 [Member] | Swap [Member] | Crude Oil [Member] |
Derivative Financial Instruments |
Weighted- Average Contract Price | 90.78 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_ThirdQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Portion of Future Oil and Gas Production Being Hedged | 1,254,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_ThirdQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Third Quarter of 2015 [Member] | Swap [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 14,950,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_ThirdQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Weighted- Average Contract Price | 4.03 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_ThirdQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Third Quarter of 2015 [Member] | Collar [Member] | Crude Oil [Member] |
Derivative Financial Instruments |
Weighted- Average Floor Price | 85.00 us-gaap_DerivativeAverageFloorPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_ThirdQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Ceiling Price | 91.25 us-gaap_DerivativeAverageCapPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_ThirdQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Portion of Future Oil and Gas Production Being Hedged | 906,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_ThirdQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Third Quarter of 2015 [Member] | Collar [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 2,005,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_ThirdQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Floor Price | 4.00 us-gaap_DerivativeAverageFloorPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_ThirdQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Ceiling Price | 4.30 us-gaap_DerivativeAverageCapPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_ThirdQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Fourth Quarter of 2015 Member] | Swap [Member] | Crude Oil [Member] |
Derivative Financial Instruments |
Weighted- Average Contract Price | 90.15 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_FourthQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Portion of Future Oil and Gas Production Being Hedged | 1,137,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_FourthQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Fourth Quarter of 2015 Member] | Swap [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 13,570,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_FourthQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Weighted- Average Contract Price | 4.02 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_FourthQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Fourth Quarter of 2015 Member] | Collar [Member] | Crude Oil [Member] |
Derivative Financial Instruments |
Weighted- Average Floor Price | 85.00 us-gaap_DerivativeAverageFloorPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_FourthQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Ceiling Price | 92.19 us-gaap_DerivativeAverageCapPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_FourthQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Portion of Future Oil and Gas Production Being Hedged | 869,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_FourthQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Fourth Quarter of 2015 Member] | Collar [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 6,176,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_FourthQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Floor Price | 3.97 us-gaap_DerivativeAverageFloorPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_FourthQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
Weighted- Average Ceiling Price | 4.30 us-gaap_DerivativeAverageCapPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_FourthQuarterofSubsequentYearMember / us-gaap_DerivativeInstrumentRiskAxis = sm_CollarMember
2016 [Member] | Swap [Member] | Crude Oil [Member] |
Derivative Financial Instruments |
Weighted- Average Contract Price | 88.01 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_A2016Member / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Portion of Future Oil and Gas Production Being Hedged | 5,570,000 us-gaap_PortionOfFutureOilAndGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_CrudeOilMember / sm_DerivativeContractPeriodAxis = sm_A2016Member / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
2016 [Member] | Swap [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 48,896,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_A2016Member / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Weighted- Average Contract Price | 4.12 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_A2016Member / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
2017 [Member] | Swap [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 37,414,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_A2017Member / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Weighted- Average Contract Price | 4.16 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_A2017Member / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
2018 [Member] | Swap [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 35,241,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_A2018Member / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Weighted- Average Contract Price | 4.21 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_A2018Member / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
2019 [Member] | Swap [Member] | Natural Gas [Member] |
Derivative Financial Instruments |
Portion of Future Oil and Gas Production Being Hedged | 28,159,000 sm_PortionOfGasProductionBeingHedged / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_A2019Member / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember
Weighted- Average Contract Price | 4.28 us-gaap_DerivativeSwapTypeAverageFixedPrice / us-gaap_DerivativeByNatureAxis = us-gaap_NaturalGasReservesMember / sm_DerivativeContractPeriodAxis = sm_A2019Member / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_SwapMember

X
- Definition Index percent of natural gas collars + References No definition available. + Details
Name: | sm_IndexPercentOfNaturalGasCollars
Namespace Prefix: | sm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Index percent of natural gas fixed swaps + References No definition available. + Details
Name: | sm_IndexPercentOfNaturalGasFixedSwaps
Namespace Prefix: | sm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Index percent of NGL fixed swaps + References No definition available. + Details
Name: | sm_IndexPercentOfNglFixedSwaps
Namespace Prefix: | sm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Portion of Gas Production Being Hedged + References No definition available. + Details
Name: | sm_PortionOfGasProductionBeingHedged
Namespace Prefix: | sm_
Data Type: | num:energyItemType
Balance Type: | na
Period Type: | instant

X
- Definition The average cap rate on a group of price risk derivatives such as caps or collars. 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_DerivativeAverageCapPrice
Namespace Prefix: | us-gaap_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition The average floor rate on a group of price risk derivatives such as floors or collars. 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_DerivativeAverageFloorPrice
Namespace Prefix: | us-gaap_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
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: | us-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition The quantity of future oil and gas production being hedged. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 360 -Section S99 -Paragraph 2 -Subparagraph (SAB TOPIC 12.D.3(b)) -URI http://asc.fasb.org/extlink&oid=27015634&loc=d3e516453-122869 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 12 -Section D -Paragraph b -Subsection 3 + Details
Name: | us-gaap_PortionOfFutureOilAndGasProductionBeingHedged
Namespace Prefix: | us-gaap_
Data Type: | num:volumeItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | sm_DerivativeContractPeriodAxis=sm_A2016Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeContractPeriodAxis=sm_A2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeContractPeriodAxis=sm_A2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeContractPeriodAxis=sm_A2019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeContractPeriodAxis=sm_FirstQuarterofSubsequentYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeContractPeriodAxis=sm_FourthQuarterofSubsequentYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeContractPeriodAxis=sm_SecondQuarterofSubsequentYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sm_DerivativeContractPeriodAxis=sm_ThirdQuarterofSubsequentYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=sm_IfElPasoPermianMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=sm_IFEnableEastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=sm_IfHscMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=sm_IfNgplTxokMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=sm_IfNngVenturaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=sm_OPISNaturalGasolineMtBelvNonTETMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=sm_OPISPropaneMtBelvTETMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=us-gaap_CrudeOilMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=us-gaap_NaturalGasLiquidsReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=us-gaap_NaturalGasReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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