Income Taxes (Schedule Of Unrecognized Tax Benefits) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Income Tax Contingency [Line Items]
Amount that if recognized, would affect the effective tax rate or regulatory liability	$ 131
Amount that if recognized, would be recorded as a component of discontinued operations	11
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	65
Duke Energy Carolinas [Member]
Income Tax Contingency [Line Items]
Amount that if recognized, would affect the effective tax rate or regulatory liability	113
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	65
Progress Energy [Member]
Income Tax Contingency [Line Items]
Amount that if recognized, would affect the effective tax rate or regulatory liability	8
Amount that if recognized, would be recorded as a component of discontinued operations	3
Progress Energy Carolinas [Member]
Income Tax Contingency [Line Items]
Amount that if recognized, would affect the effective tax rate or regulatory liability	1
Progress Energy Florida [Member]
Income Tax Contingency [Line Items]
Amount that if recognized, would affect the effective tax rate or regulatory liability	1
Duke Energy Indiana [Member]
Income Tax Contingency [Line Items]
Amount that if recognized, would affect the effective tax rate or regulatory liability	$ 1