Retirement Benefits and Trusteed Assets (Net Periodic Benefit Costs (Credits)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 13	$ 12	$ 38	$ 36
Interest cost	53	54	158	162
Expected return on plan assets	(72)	(73)	(215)	(218)
Net actuarial (gain) loss	24	22	73	66
Prior service credit	0	(1)	(1)	(1)
Net periodic benefit cost (credit)	18	14	53	45
Pension Benefits | DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost (credit)	15	12	45	39
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	4	11	11
Interest cost	15	15	45	46
Expected return on plan assets	(29)	(29)	(89)	(88)
Net actuarial (gain) loss	0	0	1	1
Prior service credit	0	0	0	0
Net periodic benefit cost (credit)	(10)	(10)	(32)	(30)
Other Postretirement Benefits | DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	2	8	8
Interest cost	11	11	34	34
Expected return on plan assets	(19)	(20)	(58)	(58)
Net actuarial (gain) loss	(1)	(1)	(3)	(2)
Net periodic benefit cost (credit)	$ (6)	$ (8)	$ (19)	$ (18)