Fair Value (Fair Value and Unrealized Gains and Losses for the Nuclear Decommissioning Trust Funds) (Details) - DTE Electric - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 1,913	$ 1,825
Unrealized Gains	467	406
Unrealized Losses	(93)	(102)
Cash equivalents
Debt Securities, Available-for-sale [Line Items]
Fair Value	39	42
Unrealized Gains	0	0
Unrealized Losses	0	0
Private equity and other
Debt Securities, Available-for-sale [Line Items]
Fair Value	308	262
Unrealized Gains	76	63
Unrealized Losses	(7)	(5)
Hedge funds and similar investments
Debt Securities, Available-for-sale [Line Items]
Fair Value	172	119
Unrealized Gains	3	0
Unrealized Losses	(14)	(18)
Equity securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	852	839
Unrealized Gains	388	342
Unrealized Losses	(19)	(23)
Fixed income securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	542	563
Unrealized Gains	0	1
Unrealized Losses	$ (53)	$ (56)