Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	$ 35	$ 24
Contract services	17	9
Equity earnings of equity method investees	3	7
Investment income	1	1
Other	3	3
Total other income	59	44
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	34	24
Contract services	16	9
Investment income	1	1
Other	3	2
Total other income	$ 54	$ 36