Income Taxes (Deferred Tax Assets (Liabilities)) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Components of Deferred Tax Assets and Liabilities [Abstract]
Property, plant, and equipment	$ (4,032,000,000)	$ (3,755,000,000)
Regulatory assets and liabilities	(108,000,000)	(47,000,000)
Tax credit carry-forwards	1,144,000,000	1,161,000,000
Pension and benefits	321,000,000	300,000,000
Federal net operating loss carry-forward	265,000,000	276,000,000
State and local net operating loss carry-forwards	155,000,000	117,000,000
Investments in equity method investees	(667,000,000)	(465,000,000)
Other	141,000,000	138,000,000
Deferred tax liabilities, gross	(2,781,000,000)	(2,275,000,000)
Less valuation allowance	(41,000,000)	(40,000,000)
Deferred income tax liabilities	(2,822,000,000)	(2,315,000,000)
Deferred income tax assets	2,241,000,000	2,264,000,000
Deferred income tax liabilities	(5,063,000,000)	(4,579,000,000)
DTE Electric
Components of Deferred Tax Assets and Liabilities [Abstract]
Property, plant, and equipment	(3,099,000,000)	(2,956,000,000)
Regulatory assets and liabilities	(53,000,000)
Regulatory assets and liabilities		4,000,000
Tax credit carry-forwards	278,000,000	252,000,000
Pension and benefits	264,000,000	258,000,000
Federal net operating loss carry-forward	0	0
State and local net operating loss carry-forwards	0	0
Investments in equity method investees	0	0
Other	85,000,000	87,000,000
Deferred tax liabilities, gross	(2,525,000,000)	(2,355,000,000)
Less valuation allowance	0	0
Deferred income tax liabilities	(2,525,000,000)	(2,355,000,000)
Deferred income tax assets	883,000,000	865,000,000
Deferred income tax liabilities	$ (3,408,000,000)	$ (3,220,000,000)