Significant Accounting Policies (Financing Receivables Classified by Internal Grade of Credit Risk) (Details) $ in Millions |
Jun. 30, 2026
USD ($)
|
|---|---|
| Notes receivable | |
| Year of Origination | |
| 2026 | $ 40 |
| 2025 | 261 |
| 2024 and Prior | 1,298 |
| Total | 1,599 |
| Notes receivable | Internal grade 1 | |
| Year of Origination | |
| 2026 | 38 |
| 2025 | 247 |
| 2024 and Prior | 30 |
| Total | 315 |
| Notes receivable | Internal grade 1 | DTE Electric | |
| Year of Origination | |
| 2026 | 14 |
| 2025 | 247 |
| 2024 and Prior | 27 |
| Total | 288 |
| Notes receivable | Internal grade 2 | |
| Year of Origination | |
| 2026 | 2 |
| 2025 | 14 |
| 2024 and Prior | 1,268 |
| Total | 1,284 |
| Net investment in leases | |
| Year of Origination | |
| 2026 | 0 |
| 2025 | 0 |
| 2024 and Prior | 35 |
| Total | 35 |
| Net investment in leases | Internal grade 1 | |
| Year of Origination | |
| 2026 | 0 |
| 2025 | 0 |
| 2024 and Prior | 34 |
| Total | 34 |
| Net investment in leases | Internal grade 2 | |
| Year of Origination | |
| 2026 | 0 |
| 2025 | 0 |
| 2024 and Prior | 1 |
| Total | $ 1 |