Income Taxes (Components of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current income tax expense (benefit)
Federal	$ (17)	$ (22)	$ (1)
State and other income tax	1	1	7
Total current income taxes	(16)	(21)	6
Deferred income tax expense
Federal	38	118	184
State and other income tax	76	78	81
Total deferred income taxes	114	196	265
Total	98	175	271
DTE Electric
Current income tax expense (benefit)
Federal	0	(17)	0
State and other income tax	4	(1)	11
Total current income taxes	4	(18)	11
Deferred income tax expense
Federal	131	270	268
State and other income tax	58	75	74
Total deferred income taxes	189	345	342
Total	$ 193	$ 327	$ 353