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Financial and Other Derivative Instruments (Cumulative Gross Volume of Derivative Contracts Outstanding) (Details) (CAD)
Dec. 31, 2014
MMBTU
Natural Gas Commodity Contract [Member]  
Derivative [Line Items]  
Derivative outstanding, energy 895,599,953dte_DerivativeNonmonetaryAmountEnergy
/ us-gaap_DerivativeInstrumentRiskAxis
= dte_NaturalGasCommodityContractMember
Electricity Commodity Contract [Member]  
Derivative [Line Items]  
Derivative outstanding, energy 11,296,153dte_DerivativeNonmonetaryAmountEnergy
/ us-gaap_DerivativeInstrumentRiskAxis
= dte_ElectricityCommodityContractMember
Foreign Currency Exchange Contract [Member]  
Derivative [Line Items]  
Foreign Currency Exchange (Canadian dollars) 63,022,462us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember