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Fair Value (Details Textuals) (USD $)
3 Months Ended 12 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2013
Dec. 31, 2014
Fair Value, Option, Quantitative Disclosures [Line Items]        
Assets Level 1 to Level 2 $ 0us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount $ 0us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount    
Assets Level 2 to Level 1 0us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount 0us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount    
Liabilities Level 1 to Level 2 0us-gaap_FairValueLiabilitiesLevel1ToLevel2TransfersAmount 0us-gaap_FairValueLiabilitiesLevel1ToLevel2TransfersAmount    
Liabilities Level 2 to Level 1 0us-gaap_FairValueLiabilitiesLevel2ToLevel1TransfersAmount 0us-gaap_FairValueLiabilitiesLevel2ToLevel1TransfersAmount    
Trading securities realized gain (loss) 1,000,000us-gaap_TradingSecuritiesRealizedGainLoss 2,000,000us-gaap_TradingSecuritiesRealizedGainLoss    
Accumulated Net Unrealized Investment Gain (Loss)        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Unrealized losses on available for sale securities 0us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
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0us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
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Nuclear decommissioning trust fund        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Average maturity of debt securities     7 years  
DTE Electric        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Transfers between Level 3 0us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationTransfersNet
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0us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationTransfersNet
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Trading securities realized gain (loss) 1,000,000us-gaap_TradingSecuritiesRealizedGainLoss
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2,000,000us-gaap_TradingSecuritiesRealizedGainLoss
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DTE Electric | Accumulated Net Unrealized Investment Gain (Loss)        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Unrealized losses on available for sale securities 0us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
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DTE Electric | Nuclear decommissioning trust fund        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Cash and cash equivalents 5,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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    11,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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Average maturity of debt securities 7 years      
Recurring        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Cash and cash equivalents 17,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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    112,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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Recurring | DTE Electric        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Cash and cash equivalents 8,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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    104,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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Restricted assets | Recurring        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Cash and cash equivalents 9,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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    105,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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Restricted assets | Recurring | DTE Electric        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Cash and cash equivalents       96,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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Other investments | Recurring        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Cash and cash equivalents 8,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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    7,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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Other investments | Recurring | DTE Electric        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Cash and cash equivalents       8,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
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Other investments | Recurring | Equity        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Other investments $ 151,000,000us-gaap_InvestmentsFairValueDisclosure
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    $ 150,000,000us-gaap_InvestmentsFairValueDisclosure
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