Property, Plant, and Equipment (Schedule of Interest Costs Capitalized) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property, Plant, and Equipment [Line Items]
Allowance for debt funds used during construction and interest capitalized	$ 13	$ 10
Allowance for equity funds used during construction	23	21
Total	36	31
DTE Electric
Property, Plant, and Equipment [Line Items]
Allowance for debt funds used during construction and interest capitalized	8	8
Allowance for equity funds used during construction	18	18
Total	$ 26	$ 26