Property, Plant, and Equipment (Depreciation and Amortization) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	$ 865	$ 783	$ 740
Regulatory assets and liabilities	165	193	150
Securitized regulatory assets	0	0	(38)
Depreciation and amortization	1,030	976	852
DTE Electric
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	620	582	545
Regulatory assets and liabilities	133	168	126
Securitized regulatory assets	0	0	(38)
Depreciation and amortization	$ 753	$ 750	$ 633