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Fair Value (Details Textuals) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Fair Value, Option, Quantitative Disclosures [Line Items]        
Trading securities realized gain (loss) $ 5,000,000 $ 5,000,000 $ 13,000,000 $ 10,000,000
DTE Electric        
Fair Value, Option, Quantitative Disclosures [Line Items]        
Trading securities realized gain (loss) 5,000,000 5,000,000 13,000,000 10,000,000
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