Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	$ 105	$ 86	$ 42
Equity earnings of equity method investees	47	15	3
Contract services	43	34	26
Investment income	17	17	17
Other	18	15	14
Other income	230	167	102
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	103	84	40
Contract services	43	33	25
Investment income	14	13	11
Other	11	14	11
Other income	$ 171	$ 144	$ 87