v3.26.1
Financial and Other Derivative Instruments (Effect of Derivatives Not Designated as Hedging Instruments) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Derivative Instruments, Gain (Loss) [Line Items]        
Total $ 63 $ 69 $ (72) $ 117
Natural gas | Income Statement Location [Axis]: us-gaap:UnregulatedOperatingRevenue        
Derivative Instruments, Gain (Loss) [Line Items]        
Total (4) (10) (116) 84
Natural gas | Income Statement Location [Axis]: dte:UnregulatedOperatingExpenseProductsAndServices        
Derivative Instruments, Gain (Loss) [Line Items]        
Total 30 (46) 55 (146)
Electricity | Income Statement Location [Axis]: us-gaap:UnregulatedOperatingRevenue        
Derivative Instruments, Gain (Loss) [Line Items]        
Total 44 111 (9) 156
Environmental & Other | Income Statement Location [Axis]: us-gaap:UnregulatedOperatingRevenue        
Derivative Instruments, Gain (Loss) [Line Items]        
Total (6) 14 (2) 23
Foreign currency exchange contracts | Income Statement Location [Axis]: us-gaap:UnregulatedOperatingRevenue        
Derivative Instruments, Gain (Loss) [Line Items]        
Total $ (1) $ 0 $ 0 $ 0