XML 81 R65.htm IDEA: XBRL DOCUMENT v3.23.1
Fair Value (Fair Value and Unrealized Gains and Losses for the Nuclear Decommissioning Trust Funds) (Details) - DTE Electric - USD ($)
$ in Millions
Mar. 31, 2023
Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]    
Fair Value $ 1,896 $ 1,825
Unrealized Gains 447 406
Unrealized Losses (77) (102)
Cash equivalents    
Debt Securities, Available-for-sale [Line Items]    
Fair Value 53 42
Unrealized Gains 0 0
Unrealized Losses 0 0
Private equity and other    
Debt Securities, Available-for-sale [Line Items]    
Fair Value 269 262
Unrealized Gains 62 63
Unrealized Losses (6) (5)
Hedge funds and similar investments    
Debt Securities, Available-for-sale [Line Items]    
Fair Value 122 119
Unrealized Gains 0 0
Unrealized Losses (15) (18)
Equity securities    
Debt Securities, Available-for-sale [Line Items]    
Fair Value 879 839
Unrealized Gains 382 342
Unrealized Losses (17) (23)
Fixed income securities    
Debt Securities, Available-for-sale [Line Items]    
Fair Value 573 563
Unrealized Gains 3 1
Unrealized Losses $ (39) $ (56)