Long-Term Debt (Debt Redemptions) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)
Debt Instrument [Line Items]
Debt redemption amount	$ 260
Securitization Bonds | DTE Electric | March 2015 Securitization Bonds 6.62% due 2015
Debt Instrument [Line Items]
Interest Rate	6.62%
Debt redemption amount	$ 105
Mortgages | DTE Electric | March 2015 7.904% Mortgage Bonds Due 2016
Debt Instrument [Line Items]
Interest Rate	7.904%
Debt redemption amount	$ 10
Senior Notes | DTE Gas | September 2015 5.94% Senior Notes Due 2015
Debt Instrument [Line Items]
Interest Rate	5.94%
Debt redemption amount	$ 140
Other Long Term Debt | Various Other Long Term Debt Due 2015
Debt Instrument [Line Items]
Debt redemption amount	$ 5