Long-Term Debt (Schedule of Issued Debt) (Details)	Sep. 30, 2019 USD ($)
Debt Instrument [Line Items]
Debt issued	$ 1,450,000,000
DTE Energy | Senior Notes | June 2019 2.60% Senior Notes Maturing 2022
Debt Instrument [Line Items]
Interest rate	2.60%
Debt issued	$ 300,000,000
DTE Energy | Senior Notes | June 2019 3.40% Senior Notes Maturing 2029
Debt Instrument [Line Items]
Interest rate	3.40%
Debt issued	$ 500,000,000
DTE Electric | Mortgage Bonds | February 2019 3.95% Mortgage Bonds Maturing 2049
Debt Instrument [Line Items]
Interest rate	3.95%
Debt issued	$ 650,000,000