Fair Value (Fair Value and Unrealized Gains and Losses for Nuclear Decommissioning Trust Funds) (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Cash equivalents
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 30	$ 35
Private equity and other
Debt Securities, Available-for-sale [Line Items]
Fair Value	368	358
Hedge funds and similar investments
Debt Securities, Available-for-sale [Line Items]
Fair Value	245	245
Equity securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	1,195	1,188
Fixed income securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	761	726
DTE Electric
Debt Securities, Available-for-sale [Line Items]
Fair Value	2,599	2,552
Unrealized Gains	930	900
Unrealized Losses	(50)	(40)
DTE Electric | Cash equivalents
Debt Securities, Available-for-sale [Line Items]
Fair Value	30	35
Unrealized Gains	0	0
Unrealized Losses	0	0
DTE Electric | Private equity and other
Debt Securities, Available-for-sale [Line Items]
Fair Value	368	358
Unrealized Gains	131	125
Unrealized Losses	(8)	(7)
DTE Electric | Hedge funds and similar investments
Debt Securities, Available-for-sale [Line Items]
Fair Value	245	245
Unrealized Gains	7	8
Unrealized Losses	(10)	(6)
DTE Electric | Equity securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	1,195	1,188
Unrealized Gains	767	742
Unrealized Losses	(13)	(10)
DTE Electric | Fixed income securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	761	726
Unrealized Gains	25	25
Unrealized Losses	$ (19)	$ (17)