Property, Plant, and Equipment (Schedule of Interest Costs Capitalized) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant, and Equipment [Line Items]
Allowance for debt funds used during construction and interest capitalized	$ 15	$ 13
Allowance for equity funds used during construction	28	23
Total	43	36
DTE Electric
Property, Plant, and Equipment [Line Items]
Allowance for debt funds used during construction and interest capitalized	9	8
Allowance for equity funds used during construction	19	18
Total	$ 28	$ 26