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Long-Term Debt (Long Term Debt Outstanding and Weighted Average Interest Rates) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Debt Instrument [Line Items]    
Other Long-Term Debt, Including Non-Recourse Debt $ 9,300  
DTE Energy Total Long-Term Debt 8,805 $ 8,021
Less amount due within one year for DTE Energy (465) (161)
Long-term Debt, Excluding Current Maturities 8,340 7,860
Less amount due within one year 0 (105)
Securitization bonds, Excluding Current Maturities 0 0
DTE Energy Junior Subordinated Debentures $ 480 480
6.5% Junior Subordinated Debentures Due 2061 | Junior Subordinated Debentures    
Debt Instrument [Line Items]    
Interest rate 6.50%  
Maturity date Dec. 01, 2061  
DTE Energy Junior Subordinated Debentures $ 280 280
5.25% Junior Subordinated Debentures Due 2062 | Junior Subordinated Debentures    
Debt Instrument [Line Items]    
Interest rate 5.30%  
Maturity date Dec. 01, 2062  
DTE Energy Junior Subordinated Debentures $ 200 200
DTE Energy | DTE Energy Debt, Unsecured | Unsecured Debt    
Debt Instrument [Line Items]    
Interest rate 4.40%  
Maturity start Jun. 01, 2016  
Maturity end Apr. 15, 2033  
Other Long-Term Debt, Including Non-Recourse Debt $ 1,947 1,647
DTE Electric    
Debt Instrument [Line Items]    
Other Long-Term Debt, Including Non-Recourse Debt 5,635  
DTE Energy Total Long-Term Debt 5,624 5,154
Less amount due within one year for DTE Energy (151) (10)
Long-term Debt, Excluding Current Maturities 5,473 5,144
Less amount due within one year 0 (105)
Securitization bonds, Excluding Current Maturities $ 0 0
DTE Electric | DTE Electric Taxable Debt, Principally Secured | Secured Debt    
Debt Instrument [Line Items]    
Interest rate 4.40%  
Maturity start Mar. 31, 2016  
Maturity end Mar. 15, 2045  
Other Long-Term Debt, Including Non-Recourse Debt $ 5,314 4,824
DTE Electric | DTE Electric Tax-Exempt Revenue Bonds (b) | Tax-Exempt Revenue Bonds    
Debt Instrument [Line Items]    
Interest rate 5.20%  
Maturity start Jul. 01, 2020  
Maturity end Dec. 01, 2030  
Other Long-Term Debt, Including Non-Recourse Debt $ 310 330
DTE Electric | DTE Electric Securitization Bonds    
Debt Instrument [Line Items]    
Interest rate 6.60%  
Maturity date Mar. 15, 2015  
DTE Electric Securitization Bonds $ 0 105
DTE Gas | Other Long-Term Debt    
Debt Instrument [Line Items]    
Other Long-Term Debt, Including Non-Recourse Debt $ 110 121
DTE Gas | DTE Gas Taxable Debt, Principally Secured | Secured Debt    
Debt Instrument [Line Items]    
Interest rate 4.90%  
Maturity start Apr. 15, 2018  
Maturity end Sep. 01, 2045  
Other Long-Term Debt, Including Non-Recourse Debt $ 1,124 $ 1,099