Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	$ 18	$ 9
Contract services	7	6
Investment income	6	5
Equity earnings (losses) of equity method investees	(8)	4
Other	4	2
Total other income	27	26
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	18	9
Contract services	6	6
Investment income	5	3
Other	3	2
Total other income	$ 32	$ 20