Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	$ 8	$ 6	$ 26	$ 20
Contract services	5	7	18	21
Investment income	0	0	9	0
Equity earnings (losses) of equity method investees	3	0	7	(15)
Other	(3)	3	10	9
Total other income	13	16	70	35
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	8	6	25	18
Contract services	6	7	18	21
Investment income	0	0	6	0
Other	2	2	7	7
Total other income	$ 16	$ 15	$ 56	$ 46