Retirement Benefits and Trusteed Assets (OPEB - Fair Value Measurements) (Details) - Other postretirement benefit plan - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 1,594	$ 1,614	$ 1,577
Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	276	308
Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	529	511
Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	789	795
Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	33	41
Short-term Investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	33	41
Short-term Investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Short-term Investments | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Equity Securities, Domestic
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	67	76
Equity Securities, Domestic | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Equity Securities, Domestic | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Equity Securities, Domestic | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	67	76
Equity Securities, International
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	40	50
Equity Securities, International | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	6	7
Equity Securities, International | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Equity Securities, International | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	34	43
Fixed Income Securities, Governmental
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	244	273
Fixed Income Securities, Governmental | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	210	242
Fixed Income Securities, Governmental | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	34	31
Fixed Income Securities, Governmental | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Fixed Income Securities, Corporate
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	700	671
Fixed Income Securities, Corporate | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Fixed Income Securities, Corporate | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	492	459
Fixed Income Securities, Corporate | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	208	212
Hedge Funds and Similar Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	133	125
Hedge Funds and Similar Investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	27	18
Hedge Funds and Similar Investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	3	21
Hedge Funds and Similar Investments | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	103	86
Private Equity and Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	377	378
Private Equity and Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Private Equity and Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Private Equity and Other | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	377	378
DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	1,052	1,070	$ 1,052
DTE Electric | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	180	203
DTE Electric | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	348	337
DTE Electric | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	524	530
DTE Electric | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	21	27
DTE Electric | Short-term Investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	21	27
DTE Electric | Short-term Investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Short-term Investments | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Equity Securities, Domestic
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	42	48
DTE Electric | Equity Securities, Domestic | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Equity Securities, Domestic | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Equity Securities, Domestic | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	42	48
DTE Electric | Equity Securities, International
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	26	31
DTE Electric | Equity Securities, International | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	4	4
DTE Electric | Equity Securities, International | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Equity Securities, International | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	22	27
DTE Electric | Fixed Income Securities, Governmental
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	160	182
DTE Electric | Fixed Income Securities, Governmental | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	138	161
DTE Electric | Fixed Income Securities, Governmental | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	22	21
DTE Electric | Fixed Income Securities, Governmental | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Fixed Income Securities, Corporate
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	465	447
DTE Electric | Fixed Income Securities, Corporate | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Fixed Income Securities, Corporate | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	324	302
DTE Electric | Fixed Income Securities, Corporate | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	141	145
DTE Electric | Hedge Funds and Similar Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	88	83
DTE Electric | Hedge Funds and Similar Investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	17	11
DTE Electric | Hedge Funds and Similar Investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	2	14
DTE Electric | Hedge Funds and Similar Investments | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	69	58
DTE Electric | Private Equity and Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	250	252
DTE Electric | Private Equity and Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Private Equity and Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Private Equity and Other | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 250	$ 252