Fair Value (Fair Value of Nuclear Decommissioning Trust Fund Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	$ 2,706	$ 2,552
DTE Electric
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	2,706	2,552
DTE Electric | Nuclear decommissioning trust fund
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	2,706	2,552
DTE Electric | Nuclear decommissioning trust fund | Fermi 2
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	2,673	2,523
DTE Electric | Nuclear decommissioning trust fund | Fermi 1
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	3	3
DTE Electric | Nuclear decommissioning trust fund | Low-level radioactive waste
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	$ 30	$ 26