Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Schedule of Other Nonoperating Income, by Component [Line Items]
Contract services	$ 7	$ 7	$ 14	$ 15
Allowance for equity funds used during construction	6	6	14	13
Income from REF entities	0	21	0	45
Gains from rabbi trust securities	0	2	0	4
Equity earnings (losses) of equity method investees	(4)	13	(15)	14
Other	2	5	6	6
Total other income	11	54	19	97
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Contract services	7	7	14	15
Allowance for equity funds used during construction	5	6	12	12
Gains from rabbi trust securities	0	2	0	4
Other	3	4	5	7
Total other income	$ 15	$ 19	$ 31	$ 38