Leases (Finance Leases Reported on Consolidated Statements of Financial Position) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Lessee, Lease, Description [Line Items]
Right-of-use assets, within Property, plant, and equipment, net	$ 18	$ 23
Current lease liabilities, within Current portion of long-term debt	4	5
Long-term lease liabilities	$ 14	$ 18
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Long-Term Debt and Lease Obligation, Current	Long-Term Debt and Lease Obligation, Current
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, Plant and Equipment, Net	Property, Plant and Equipment, Net
DTE Electric
Lessee, Lease, Description [Line Items]
Right-of-use assets, within Property, plant, and equipment, net	$ 9	$ 12
Current lease liabilities, within Current portion of long-term debt	3	4
Long-term lease liabilities	$ 6	$ 8
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Long-Term Debt and Lease Obligation, Current	Long-Term Debt and Lease Obligation, Current