Regulatory Matters (Schedule of Net Carrying Value Of Facilities and Megawatt Capacity) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($) MW	Dec. 31, 2014 USD ($)
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	$ 73,776	$ 70,046
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,541
Remaining net book value (in millions)	$ 207
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	25,208	24,672
Duke Energy Carolinas [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	110
Progress Energy [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	$ 27,538	25,144
Progress Energy [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	873
Remaining net book value (in millions)	$ 121
Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	$ 17,172	15,186
Duke Energy Progress [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	376
Remaining net book value (in millions)	$ 460
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	$ 10,363	9,955
Duke Energy Florida [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	873
Remaining net book value (in millions)	$ 121
Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	5,175	4,937
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	$ 9,340	$ 8,815
Duke Energy Indiana [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	668
Remaining net book value (in millions)	$ 86