Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	$ 9	$ 8
Contract services	6	7
Equity earnings (losses) of equity method investees	4	(11)
Other	7	4
Total other income	26	8
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Allowance for equity funds used during construction	9	7
Contract services	6	7
Other	5	2
Total other income	$ 20	$ 16