Variable Interest Entities (Schedule of Accounts Receivable Securitizations) (Details) |
Sep. 30, 2015
USD ($)
|
|---|---|
| Variable Interest Entities [Line Items] | |
| Debt Instrument, Face Amount | $ 1,700,000,000 |
| Duke Energy Carolinas [Member] | |
| Variable Interest Entities [Line Items] | |
| Debt Instrument, Face Amount | 500,000,000 |
| Duke Energy Progress [Member] | |
| Variable Interest Entities [Line Items] | |
| Debt Instrument, Face Amount | 1,200,000,000 |
| DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member] | |
| Variable Interest Entities [Line Items] | |
| Debt Instrument, Face Amount | 400,000,000 |
| DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member] | |
| Variable Interest Entities [Line Items] | |
| Debt Instrument, Face Amount | 300,000,000 |
| DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member] | |
| Variable Interest Entities [Line Items] | |
| Debt Instrument, Face Amount | $ 225,000,000 |