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Fair Value (Fair Value and Unrealized Gains and Losses for the Nuclear Decommissioning Trust Funds) (Details) - DTE Electric - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]    
Fair Value $ 2,256 $ 2,041
Unrealized Gains 687 545
Unrealized Losses (58) (58)
Cash equivalents    
Debt Securities, Available-for-sale [Line Items]    
Fair Value 26 34
Private Equity and Other    
Debt Securities, Available-for-sale [Line Items]    
Fair Value 349 312
Unrealized Gains 106 74
Unrealized Losses (8) (8)
Hedge Funds and Similar Investments    
Debt Securities, Available-for-sale [Line Items]    
Fair Value 228 184
Unrealized Gains 7 4
Unrealized Losses (5) (9)
Equity securities    
Debt Securities, Available-for-sale [Line Items]    
Fair Value 1,003 921
Unrealized Gains 558 459
Unrealized Losses (16) (11)
Fixed Income Securities    
Debt Securities, Available-for-sale [Line Items]    
Fair Value 650 590
Unrealized Gains 16 8
Unrealized Losses $ (29) $ (30)