v2.4.0.8

Business Segments (Narrative) (Details) (USD $) In Millions, unless otherwise specified | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013
Segment Reporting Information [Line Items] |  |  |  |
Interest Expense | $ 405 | $ 378 | $ 1,212 | $ 1,125
Progress Energy [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Interest Expense | 166 | 162 | 502 | 520
Duke Energy Ohio [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Interest Expense | 20 | 14 | 60 | 47
Other [Member] | Progress Energy [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Interest Expense | $ 58 | $ 64 | $ 181 | $ 235
National Methanol Company [Member] | International Energy [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Equity Method Investment, Ownership Percentage | 25.00% |  | 25.00% |

X
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