Fair Value (Carrying Amount of Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Carrying amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	$ 1,616	$ 1,453
Short-term borrowings	737	882
Notes payable	16	28
Long-term debt	27,777	25,123
Carrying amount | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	273	274
Short-term borrowings	737	652
Notes payable	13	24
Long-term debt	14,523	13,165
Carrying amount | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	726	0
Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	0	0
Notes payable	0	0
Long-term debt	1,085	1,285
Fair Value | Level 1 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	0	0
Notes payable	0	0
Long-term debt	0	0
Fair Value | Level 1 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	737	882
Notes payable	0	0
Long-term debt	22,626	21,204
Fair Value | Level 2 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	737	652
Notes payable	0	0
Long-term debt	12,522	12,048
Fair Value | Level 2 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	1,563	1,482
Short-term borrowings	0	0
Notes payable	16	28
Long-term debt	1,086	1,351
Fair Value | Level 3 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	294	289
Short-term borrowings	0	0
Notes payable	13	24
Long-term debt	0	131
Fair Value | Level 3 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	$ 726	$ 0