Variable Interest Entities (Fair Value Assumptions)(Details) - Cinergy Receivables [Member] |
9 Months Ended | |
|---|---|---|
Sep. 30, 2015 |
Sep. 30, 2014 |
|
| Duke Energy Ohio [Member] | ||
| Variable Interest Entities [Line Items] | ||
| Anticipated credit loss ratio | 0.60% | 0.60% |
| Discount rate | 1.20% | 1.20% |
| Receivable turnover rate | 12.90% | 12.80% |
| Duke Energy Indiana [Member] | ||
| Variable Interest Entities [Line Items] | ||
| Anticipated credit loss ratio | 0.30% | 0.30% |
| Discount rate | 1.20% | 1.20% |
| Receivable turnover rate | 10.60% | 10.50% |