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Fair Value (Fair Value of Nuclear Decommissioning Trust Fund Assets) (Details) - USD ($)
$ in Millions
Sep. 30, 2017
Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]    
Nuclear decommissioning trust funds $ 1,439 $ 1,320
DTE Electric    
Schedule of Available-for-sale Securities [Line Items]    
Nuclear decommissioning trust funds 1,439 1,320
DTE Electric | Nuclear decommissioning trust fund    
Schedule of Available-for-sale Securities [Line Items]    
Nuclear decommissioning trust funds 1,439 1,320
DTE Electric | Nuclear decommissioning trust fund | Fermi 2    
Schedule of Available-for-sale Securities [Line Items]    
Nuclear decommissioning trust funds 1,423 1,291
DTE Electric | Nuclear decommissioning trust fund | Fermi 1    
Schedule of Available-for-sale Securities [Line Items]    
Nuclear decommissioning trust funds 3 3
DTE Electric | Nuclear decommissioning trust fund | Low-level radioactive waste    
Schedule of Available-for-sale Securities [Line Items]    
Nuclear decommissioning trust funds $ 13 $ 26