Income Taxes (Reconciliation of Income Tax Expense to the Statutory Federal Income Tax Rate) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Entity Information [Line Items]
Statutory rate		21.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income Before Income Taxes		$ 1,216	$ 1,287	$ 1,105
Income tax expense at statutory rate - 21% in 2018 - 35% in 2017 and 2016		255	450	387
Production tax credits		(223)	(189)	(145)
Investment tax credits		(4)	(4)	(5)
Depreciation		2	(4)	(4)
Noncontrolling interests		2	8	12
AFUDC equity		(14)	(18)	(10)
Employee Stock Ownership Plan dividends		(3)	(5)	(5)
Stock based compensation		(3)	(14)	0
Subsidiary stock loss		0	0	(10)
State and local income taxes, net of federal benefit		60	51	58
Enactment of the Tax Cuts and Jobs Act	$ (105)	21	(105)	0
Other, net		5	5	(7)
Income Tax Expense		$ 98	$ 175	$ 271
Effective income tax rate		8.10%	13.60%	24.50%
DTE Electric
Entity Information [Line Items]
Statutory rate		21.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income Before Income Taxes		$ 857	$ 928	$ 975
Income tax expense at statutory rate - 21% in 2018 - 35% in 2017 and 2016		180	325	341
Production tax credits		(35)	(36)	(30)
Investment tax credits		(3)	(4)	(4)
Depreciation		2	3	3
AFUDC equity		(3)	(5)	(6)
Employee Stock Ownership Plan dividends		(2)	(3)	(3)
State and local income taxes, net of federal benefit		49	48	56
Enactment of the Tax Cuts and Jobs Act		7	0	0
Other, net		(2)	(1)	(4)
Income Tax Expense		$ 193	$ 327	$ 353
Effective income tax rate		22.50%	35.20%	36.20%