Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	$ 24	$ 18
Contract services	9	7
Equity earnings (losses) of equity method investees	7	(8)
Investment income	1	6
Other	3	4
Total other income	44	27
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	24	18
Contract services	9	6
Investment income	1	5
Other	2	3
Total other income	$ 36	$ 32