Long-Term Debt (Debt Issuances) (Details) $ in Millions	Sep. 30, 2025 USD ($)
Debt Instrument [Line Items]
Amount	$ 4,060
Senior Notes | February 2025 5.20% Senior Notes Maturing In 2030
Debt Instrument [Line Items]
Interest Rate	5.20%
Amount	$ 1,100
Senior Notes | September 2025 4.88% Senior Notes Maturing In 2028
Debt Instrument [Line Items]
Interest Rate	4.88%
Amount	$ 250
Senior Notes | September 2025 5.05% Senior Notes Maturing In 2035
Debt Instrument [Line Items]
Interest Rate	5.05%
Amount	$ 550
Mortgage Bonds | May 2025 5.25% Mortgage Bonds Maturing In 2035 | DTE Electric
Debt Instrument [Line Items]
Interest Rate	5.25%
Amount	$ 500
Mortgage Bonds | May 2025 5.85% Mortgage Bonds Maturing In 2055 | DTE Electric
Debt Instrument [Line Items]
Interest Rate	5.85%
Amount	$ 500
Mortgage Bonds | May 2025 4.25% Mortgage Bonds Maturing In 2027 | DTE Electric
Debt Instrument [Line Items]
Interest Rate	4.25%
Amount	$ 300
Mortgage Bonds | September 2025 4.71% Mortgage Bonds Maturing In 2031 | DTE Gas
Debt Instrument [Line Items]
Interest Rate	4.71%
Amount	$ 50
Mortgage Bonds | September 2025 5.36% Mortgage Bonds Maturing In 2037 | DTE Gas
Debt Instrument [Line Items]
Interest Rate	5.36%
Amount	$ 75
Mortgage Bonds | September 2025 5.96% Mortgage Bonds Maturing In 2055 | DTE Gas
Debt Instrument [Line Items]
Interest Rate	5.96%
Amount	$ 135
Junior Subordinated Debentures | September 2025 6.25% Junior Subordinated Debentures Maturing In 2085
Debt Instrument [Line Items]
Interest Rate	6.25%
Amount	$ 600