Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Schedule of Other Nonoperating Income, by Component [Line Items]
Contract services	$ 7	$ 6	$ 21	$ 21
Allowance for equity funds used during construction	6	7	20	20
Income from REF entities	0	57	0	102
Gains from rabbi trust securities	0	0	0	4
Equity earnings (losses) of equity method investees	0	17	(15)	31
Other	3	3	9	9
Total other income	16	90	35	187
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Contract services	7	6	21	21
Allowance for equity funds used during construction	6	6	18	18
Gains from rabbi trust securities	0	0	0	4
Other	2	2	7	9
Total other income	$ 15	$ 14	$ 46	$ 52