Retirement Benefits and Trusteed Assets (Net Periodic Benefit Costs (Credits)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 12	$ 14	$ 36	$ 43
Interest cost	54	52	162	156
Expected return on plan assets	(73)	(86)	(218)	(256)
Net actuarial (gain) loss	22	15	66	44
Prior service credit	(1)	0	(1)	(1)
Net periodic benefit cost (credit)	14	(5)	45	(14)
Pension Benefits | DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost (credit)	(12)	(1)	(39)	(4)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	4	11	13
Interest cost	15	16	46	47
Expected return on plan assets	(29)	(30)	(88)	(90)
Net actuarial (gain) loss	0	2	1	5
Prior service credit	0	(3)	0	(8)
Net periodic benefit cost (credit)	(10)	(11)	(30)	(33)
Other Postretirement Benefits | DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	3	8	10
Interest cost	11	11	34	35
Expected return on plan assets	(20)	(20)	(58)	(59)
Net actuarial (gain) loss	(1)	1	(2)	1
Prior service credit	0	(1)	0	(5)
Net periodic benefit cost (credit)	$ (8)	$ (6)	$ (18)	$ (18)