Leases (Components of Lease Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 23	$ 26	$ 22
Finance lease cost:
Amortization of right-of-use assets	4	4	7
Interest of lease liabilities	1	1	0
Total finance lease cost	5	5	7
Variable lease cost	17	17	13
Short-term lease cost	19	18	12
Total lease cost	64	66	54
DTE Electric
Lessee, Lease, Description [Line Items]
Operating lease cost	17	22	17
Finance lease cost:
Amortization of right-of-use assets	3	3	6
Interest of lease liabilities	0	1	0
Total finance lease cost	3	4	6
Variable lease cost	1	0	0
Short-term lease cost	11	10	4
Total lease cost	$ 32	$ 36	$ 27