 | srt:FuelMember | parent-child | http://fasb.org/srt/role/statement/CommonDomainMembers |
 | srt:CrudeOilMember | parent-child | http://fasb.org/srt/role/statement/CommonDomainMembers |
 | srt:HeatingOilMember | parent-child | http://fasb.org/srt/role/statement/CommonDomainMembers |
 | srt:CrudeOilAndNGLPerBarrelMember | parent-child | http://fasb.org/srt/role/statement/CommonDomainMembers |
 | srt:NaturalGasPerThousandCubicFeetMember | parent-child | http://fasb.org/srt/role/statement/CommonDomainMembers |
 | srt:FuelMember | domain-member | http://fasb.org/srt/role/statement/CommonDomainMembersCommonTable |
 | srt:CrudeOilMember | domain-member | http://fasb.org/srt/role/statement/CommonDomainMembersCommonTable |
 | srt:HeatingOilMember | domain-member | http://fasb.org/srt/role/statement/CommonDomainMembersCommonTable |
 | srt:CrudeOilAndNGLPerBarrelMember | domain-member | http://fasb.org/srt/role/statement/CommonDomainMembersCommonTable |
 | srt:NaturalGasPerThousandCubicFeetMember | domain-member | http://fasb.org/srt/role/statement/CommonDomainMembersCommonTable |
 | srt:FuelMember | parent-child | http://fasb.org/srt/role/disclosure/ExtractiveIndustries |
 | srt:CrudeOilMember | parent-child | http://fasb.org/srt/role/disclosure/ExtractiveIndustries |
 | srt:HeatingOilMember | parent-child | http://fasb.org/srt/role/disclosure/ExtractiveIndustries |
 | srt:CrudeOilAndNGLPerBarrelMember | parent-child | http://fasb.org/srt/role/disclosure/ExtractiveIndustries |
 | srt:NaturalGasPerThousandCubicFeetMember | parent-child | http://fasb.org/srt/role/disclosure/ExtractiveIndustries |
 | srt:FuelMember | domain-member | http://fasb.org/srt/role/disclosure/ExtractiveIndustriesAverageSalesPriceAndProductionCostsPerUnitOfProductionTable |
 | srt:CrudeOilMember | domain-member | http://fasb.org/srt/role/disclosure/ExtractiveIndustriesAverageSalesPriceAndProductionCostsPerUnitOfProductionTable |
 | srt:HeatingOilMember | domain-member | http://fasb.org/srt/role/disclosure/ExtractiveIndustriesAverageSalesPriceAndProductionCostsPerUnitOfProductionTable |
 | srt:CrudeOilAndNGLPerBarrelMember | domain-member | http://fasb.org/srt/role/disclosure/ExtractiveIndustriesAverageSalesPriceAndProductionCostsPerUnitOfProductionTable |
 | srt:NaturalGasPerThousandCubicFeetMember | domain-member | http://fasb.org/srt/role/disclosure/ExtractiveIndustriesAverageSalesPriceAndProductionCostsPerUnitOfProductionTable |