Income Taxes (Components of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current income tax expense (benefit)
Federal	$ (247)	$ (184)	$ (17)
State and other income tax	7	7	1
Total current income taxes	(240)	(177)	(16)
Deferred income tax expense
Federal	310	275	38
State and other income tax	97	54	76
Total deferred income taxes	407	329	114
Total income tax expense	167	152	98
DTE Electric
Current income tax expense (benefit)
Federal	15	25	0
State and other income tax	5	16	4
Total current income taxes	20	41	4
Deferred income tax expense
Federal	30	51	131
State and other income tax	59	46	58
Total deferred income taxes	89	97	189
Total income tax expense	$ 109	$ 138	$ 193