Long-Term Debt (Debt Issuances) (Details)	12 Months Ended
	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Amount	$ 1,420,000,000
Debt redeemed	$ 385,000,000
Junior subordinated debentures | 5.25% junior subordinated debentures due 2077
Debt Instrument [Line Items]
Interest Rate	5.25%
DTE Electric | Senior Notes | 5.60% Senior Notes Due 2018
Debt Instrument [Line Items]
Interest Rate	5.60%
Debt redeemed	$ 300,000,000
DTE Electric | Mortgage Bonds | August 2017 3.75% General and Refunding Mortgage Bonds maturing in 2047
Debt Instrument [Line Items]
Interest Rate	3.75%
Amount	$ 440,000,000
DTE Gas | Mortgage Bonds | September 2017 3.08% First Mortgage Bonds maturing 2029
Debt Instrument [Line Items]
Interest Rate	3.08%
Amount	$ 40,000,000
DTE Gas | Mortgage Bonds | September 2017 3.75% First Mortgage Bonds maturing 2047
Debt Instrument [Line Items]
Interest Rate	3.75%
Amount	$ 40,000,000
DTE Energy | Senior Notes | March 2017 3.80% Senior Notes due 2027
Debt Instrument [Line Items]
Interest Rate	3.80%
Amount	$ 500,000,000
DTE Energy | Junior subordinated debentures | 5.25% junior subordinated debentures due 2077
Debt Instrument [Line Items]
Interest Rate	5.25%
Amount	$ 400,000,000