Long-Term Debt (Schedule of Issued Debt) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Jun. 30, 2023	May 31, 2023	Mar. 31, 2023
Debt Instrument [Line Items]
Amount	$ 2,300
Unsecured term loan | June 2022 Unsecured Term Loan
Debt Instrument [Line Items]
Amount				$ 200
Senior Notes | May 2023 4.875% Senior Notes
Debt Instrument [Line Items]
Interest rate			4.875%
Amount			$ 800
DTE Electric | Mortgage Bonds | March 2023 5.20% Mortgage Bonds
Debt Instrument [Line Items]
Interest rate				5.20%
Amount				$ 600
DTE Electric | Mortgage Bonds | March 2023 5.40% Mortgage Bonds
Debt Instrument [Line Items]
Interest rate				5.40%
Amount				$ 600
DTE Electric | Tax-Exempt Revenue Bonds | June 2023 3.875% Tax-Exempt Revenue Bonds
Debt Instrument [Line Items]
Interest rate		3.875%
Amount		$ 100