Income Taxes (Reconciliation of Income Tax Expense to the Statutory Federal Income Tax Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income Before Income Taxes	$ 1,538	$ 1,324	$ 1,216
Income tax expense at 21% statutory rate	323	278	255
State and local income taxes, net of federal benefit	81	48	60
Production tax credits	(121)	(128)	(223)
TCJA regulatory liability amortization	(76)	(38)	0
Net operating loss carryback	(34)	0	0
AFUDC equity	(4)	(4)	(14)
Employee Stock Ownership Plan dividends	(4)	(3)	(3)
Investment tax credits	(4)	(4)	(4)
Stock based compensation	(3)	(7)	(3)
Enactment of the Tax Cuts and Jobs Act	0	0	21
Noncontrolling interests	1	0	2
Depreciation	2	2	2
Other, net	6	8	5
Income Tax Expense	$ 167	$ 152	$ 98
Effective income tax rate	10.90%	11.50%	8.10%
DTE Electric
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income Before Income Taxes	$ 887	$ 854	$ 857
Income tax expense at 21% statutory rate	186	179	180
State and local income taxes, net of federal benefit	50	49	49
Production tax credits	(55)	(45)	(35)
TCJA regulatory liability amortization	(62)	(35)	0
AFUDC equity	(4)	(4)	(3)
Employee Stock Ownership Plan dividends	(2)	(2)	(2)
Investment tax credits	(4)	(4)	(3)
Enactment of the Tax Cuts and Jobs Act	0	0	7
Depreciation	2	2	2
Other, net	(2)	(2)	(2)
Income Tax Expense	$ 109	$ 138	$ 193
Effective income tax rate	12.30%	16.20%	22.50%