v3.26.1
Financial and Other Derivative Instruments (Details Textuals) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Derivatives, Fair Value [Line Items]    
Total derivative assets, gross $ 1,001 $ 707
Letters of credit issued that could be used to offset net derivative liabilities 5 2
Letters of credit received that could be used to offset net derivative assets 19 17
Contractual obligation to post collateral in event of downgrade to below investment grade 358  
Derivative net liability position aggregate fair value 870  
Collateral already posted fair value 32  
Derivative net asset position, fair value 698  
Remaining amount of offsets to derivative net liability positions for hard and soft trigger provisions 140  
Derivatives not designated as hedging instruments    
Derivatives, Fair Value [Line Items]    
Total derivative assets, gross 987 704
Balance Sheet Location [Axis]: us-gaap:DerivativeAssetsCurrent    
Derivatives, Fair Value [Line Items]    
Total derivative assets, gross 767 482
Balance Sheet Location [Axis]: us-gaap:DerivativeAssetsNoncurrent    
Derivatives, Fair Value [Line Items]    
Total derivative assets, gross 234 225
Balance Sheet Location [Axis]: us-gaap:OtherAssetsCurrent | Derivative assets — FTRs | Derivatives not designated as hedging instruments | DTE Electric    
Derivatives, Fair Value [Line Items]    
Total derivative assets, gross $ 23 $ 11