Long-Term Debt (Debt Redemptions) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Debt Instrument, Redemption [Line Items]
Amount	$ 821
Senior Notes | October 2019 1.50% Senior Notes Maturing 2019
Debt Instrument, Redemption [Line Items]
Interest Rate	1.50%
Amount	$ 400
Senior Notes | December 2019 2.40% Senior Notes Maturing 2019
Debt Instrument, Redemption [Line Items]
Interest Rate	2.40%
Amount	$ 300
Other long-term debt
Debt Instrument, Redemption [Line Items]
Amount	$ 1
DTE Gas | Senior Notes | October 2019 5.00% Senior Notes Maturing 2019
Debt Instrument, Redemption [Line Items]
Interest Rate	5.00%
Amount	$ 120