Fair Value (Realized Gains and Losses and Proceeds from Sale of Securities by Nuclear Decommissioning Trust Funds) (Details) - DTE Electric - Nuclear decommissioning trust fund - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Debt Securities, Available-for-sale [Line Items]
Realized gains	$ 22	$ 8
Realized losses	(8)	(8)
Proceeds from sale of securities	$ 213	$ 139