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Fair Value (Details Textuals) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Fair Value, Option, Quantitative Disclosures [Line Items]        
Trading securities realized gain (loss) $ 6,000,000 $ 5,000,000 $ 19,000,000 $ 15,000,000
DTE Electric        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Trading securities realized gain (loss) 6,000,000 5,000,000 19,000,000 15,000,000
Accumulated net unrealized investment gain (loss)        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Unrealized losses on available for sale securities 0 0 0 0
Accumulated net unrealized investment gain (loss) | DTE Electric        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Unrealized losses on available for sale securities $ 0 $ 0 $ 0 $ 0