Retirement Benefits and Trusteed Assets (Details Textuals) - USD ($)	1 Months Ended	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2019	Mar. 31, 2018
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Maximum contribution amount	$ 50,000,000	$ 50,000,000
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	$ 100,000,000	$ 23,000,000	$ 30,000,000