v3.26.1
Retirement Benefits and Trusteed Assets (Net Periodic Benefit Costs (Credits)) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Pension Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost $ 12 $ 12 $ 25 $ 24
Interest cost 52 54 105 108
Expected return on plan assets (71) (72) (143) (145)
Net actuarial (gain) loss 25 22 49 44
Prior service credit (1) 0 (1) 0
Net periodic benefit cost (credit) 17 16 35 31
Pension Benefits | DTE Electric        
Defined Benefit Plan Disclosure [Line Items]        
Net periodic benefit cost (credit) 15 13 30 27
Other Postretirement Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 3 3 7 7
Interest cost 15 16 30 31
Expected return on plan assets (30) (30) (60) (59)
Net actuarial (gain) loss 1 1 1 1
Prior service credit 0 0 0 0
Net periodic benefit cost (credit) (11) (10) (22) (20)
Other Postretirement Benefits | DTE Electric        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 2 3 5 6
Interest cost 12 11 23 23
Expected return on plan assets (19) (19) (39) (38)
Net actuarial (gain) loss (1) 0 (2) (1)
Net periodic benefit cost (credit) $ (6) $ (5) $ (13) $ (10)