Significant Accounting Policies (Financing Receivables Classified by Internal Grade of Credit Risk) (Details) $ in Millions	Dec. 31, 2025 USD ($)
Notes receivable
Year of Origination
2025	$ 251
2024	927
2023 and prior	277
Total	1,455
Notes receivable | DTE Electric
Year of Origination
Total	274
Notes receivable | Internal grade 1
Year of Origination
2025	247
2024	4
2023 and prior	27
Total	278
Notes receivable | Internal grade 1 | DTE Electric
Year of Origination
Total	274
Notes receivable | Internal grade 1 | DTE Electric | Affiliates
Year of Origination
Total	247
Notes receivable | Internal grade 2
Year of Origination
2025	4
2024	923
2023 and prior	250
Total	1,177
Notes receivable | Internal grade 2 | DTE Electric
Year of Origination
Total	0
Net investment in leases
Year of Origination
2025	0
2024	2
2023 and prior	34
Total	36
Net investment in leases | DTE Electric
Year of Origination
Total	0
Net investment in leases | Internal grade 1
Year of Origination
2025	0
2024	0
2023 and prior	34
Total	34
Net investment in leases | Internal grade 1 | DTE Electric
Year of Origination
Total	0
Net investment in leases | Internal grade 2
Year of Origination
2025	0
2024	2
2023 and prior	0
Total	2
Net investment in leases | Internal grade 2 | DTE Electric
Year of Origination
Total	$ 0