Long-Term Financings (Long-term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Total	$ 25,306
Mortgage Bonds, Notes and Other
Debt Instrument [Line Items]
Long-term debt, gross	23,154	$ 20,515
Unamortized debt discount	(14)	(28)
Unamortized debt issuance costs	(127)	(114)
Long-term debt due within one year	(1,277)	(1,220)
Long-term debt (net of current portion)	$ 21,736	19,153
Unsecured
Debt Instrument [Line Items]
Interest rate	4.70%
Long-term debt, gross	$ 7,479	6,380
Securitization Bonds
Debt Instrument [Line Items]
Unamortized debt issuance costs	(6)	(7)
Long-term debt due within one year	(75)	(71)
Long-term debt (net of current portion)	$ 561	635
Junior Subordinated Debentures
Debt Instrument [Line Items]
Interest rate	5.40%
Long-term debt, gross	$ 1,510	910
Unamortized debt issuance costs	(36)	(26)
Total	1,474	884
DTE Electric
Debt Instrument [Line Items]
Long-term debt due within one year	(677)	(350)
Total	13,262
DTE Electric | Mortgage Bonds, Notes and Other
Debt Instrument [Line Items]
Unamortized debt discount	(11)	(22)
Unamortized debt issuance costs	(80)	(73)
Long-term debt (net of current portion)	$ 11,852	10,825
DTE Electric | Principally Secured
Debt Instrument [Line Items]
Interest rate	4.20%
Long-term debt, gross	$ 12,620	11,270
DTE Electric | Securitization Bonds
Debt Instrument [Line Items]
Interest rate	5.60%
Long-term debt, gross	$ 642	713
Unamortized debt issuance costs	(6)	(7)
Long-term debt due within one year	(75)	(71)
Long-term debt (net of current portion)	$ 561	635
DTE Gas | Principally Secured
Debt Instrument [Line Items]
Interest rate	4.40%
Long-term debt, gross	$ 3,055	$ 2,865