Retirement Benefits and Trusteed Assets (OPEB - Postretirement Cost Inclusions) (Details) - Other postretirement benefit plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 18	$ 17	$ 27
Interest cost	62	65	48
Expected return on plan assets	(120)	(111)	(126)
Amortization of:
Net actuarial loss	6	10	4
Prior service credit	(10)	(19)	(19)
Net pension/other postretirement cost (credit)	(44)	(38)	(66)
DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Service cost	14	13	20
Interest cost	47	49	37
Expected return on plan assets	(79)	(73)	(85)
Amortization of:
Net actuarial loss	1	1	5
Prior service credit	(6)	(14)	(14)
Net pension/other postretirement cost (credit)	$ (23)	$ (24)	$ (37)