Property, Plant, and Equipment (Depreciation and Amortization) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	$ 1,120	$ 997	$ 878
Regulatory assets and liabilities	245	227	212
Intangible assets	71	33	27
Other	7	6	7
Depreciation and amortization	1,443	1,263	1,124
DTE Electric
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	831	748	652
Regulatory assets and liabilities	207	193	179
Other	5	5	5
Depreciation and amortization	$ 1,043	$ 946	$ 836