Property, Plant, and Equipment (Depreciation and Amortization) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	$ 912	$ 865	$ 783
Regulatory assets and liabilities	212	165	193
Depreciation and amortization	1,124	1,030	976
DTE Electric
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	657	620	582
Regulatory assets and liabilities	179	133	168
Depreciation and amortization	$ 836	$ 753	$ 750