Variable Interest Entities (Fair Value Assumptions)(Details) - Cinergy Receivables [Member] |
3 Months Ended | |
|---|---|---|
Mar. 31, 2017 |
Mar. 31, 2016 |
|
| Duke Energy Ohio [Member] | ||
| Variable Interest Entities [Line Items] | ||
| Anticipated credit loss ratio | 0.50% | 0.50% |
| Discount rate | 1.80% | 1.50% |
| Receivable turnover rate | 13.40% | 13.30% |
| Duke Energy Indiana [Member] | ||
| Variable Interest Entities [Line Items] | ||
| Anticipated credit loss ratio | 0.30% | 0.30% |
| Discount rate | 1.80% | 1.50% |
| Receivable turnover rate | 10.70% | 10.60% |