Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	$ 20	$ 9	$ 38	$ 18
Equity earnings of equity method investees	32	0	24	4
Contract services	6	7	13	13
Investment income	3	4	9	9
Other	4	11	8	13
Total other income	65	31	92	57
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	19	8	37	17
Contract services	7	6	13	12
Investment income	2	3	7	6
Other	4	3	7	5
Total other income	$ 32	$ 20	$ 64	$ 40