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Basis of Presentation (Details) (USD $)
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]      
Parent, total parent ownership percentage 60.00%tgpl_LimitedLiabilityCompanyLlcOrLimitedPartnershipLpManagingMemberOrTotalOwnershipInterest    
Parent, limited partner ownership percentage 58.00%us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPMembersOrLimitedPartnersOwnershipInterest    
Parent, general partner ownership percentage 2.00%us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterest    
Schedule of Equity Method Investments [Line Items]      
Equity method investment, distributions $ 2,000,000us-gaap_EquityMethodInvestmentDividendsOrDistributions $ 2,300,000us-gaap_EquityMethodInvestmentDividendsOrDistributions  
Equity method investment, return of capital 553,000us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital 301,000us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital  
Property, plant and equipment additions, net of equity AFUDC [Member]      
Prior Period Reclassification Adjustment [Line Items]      
Prior period reclassification adjustment   (7,400,000)us-gaap_PriorPeriodReclassificationAdjustment
/ tgpl_ScheduleOfPriorPeriodReclassificationAdjustmentAxis
= tgpl_PropertyPlantandEquipmentAdditionsNetofEquityAFUDCMember
 
Contributions and advances for construction costs [Member]      
Prior Period Reclassification Adjustment [Line Items]      
Prior period reclassification adjustment   $ 7,400,000us-gaap_PriorPeriodReclassificationAdjustment
/ tgpl_ScheduleOfPriorPeriodReclassificationAdjustmentAxis
= tgpl_ContributionsandAdvancesforConstructionCostsMember
 
Cardinal Pipeline Company, LLC [Member]      
Schedule of Equity Method Investments [Line Items]      
Equity method investment, ownership percentage 45.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= tgpl_CardinalPipelineCompanyLlcMember
  45.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= tgpl_CardinalPipelineCompanyLlcMember
Pine Needle LNG Company, LLC [Member]      
Schedule of Equity Method Investments [Line Items]      
Equity method investment, ownership percentage 35.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= tgpl_PineNeedleLngCompanyLlcMember
  35.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= tgpl_PineNeedleLngCompanyLlcMember