Retirement Benefits and Trusteed Assets (Details Textuals) (USD $) In Millions, unless otherwise specified	3 Months Ended	1 Months Ended
	Mar. 31, 2015	Apr. 24, 2015
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Estimated Future Employer Contributions in Current Fiscal Year	$ 150
Pension Benefits | Subsequent Event
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Contributions by Employer		25
Pension Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Estimated Future Employer Contributions in Current Fiscal Year	120
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Estimated Future Employer Contributions in Current Fiscal Year	80
Other Postretirement Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Estimated Future Employer Contributions in Current Fiscal Year	$ 60