Retirement Benefits and Trusteed Assets (Details Textuals) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Maximum contribution amount		$ 0		$ 0
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Maximum contribution amount		0		0
DTE Electric | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Pension cost	$ 175,000,000	$ 30,000,000	$ 33,000,000	$ 90,000,000	$ 102,000,000