Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	$ 24	$ 8	$ 62	$ 26
Equity earnings of equity method investees	12	3	36	7
Contract services	8	5	21	18
Investment income	7	0	16	9
Other	3	(3)	11	10
Total other income	54	13	146	70
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	23	8	60	25
Contract services	8	6	21	18
Investment income	6	0	13	6
Other	4	2	11	7
Total other income	$ 41	$ 16	$ 105	$ 56