Regulatory Matters (Schedule of Net Carrying Value Of Facilities and Megawatt Capacity) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) MW	Dec. 31, 2015 USD ($)
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	$ 76,432	$ 75,709
Generation Facilities To Be Retired Net	$ 644	548
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,471
Remaining net book value (in millions)	$ 300
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	26,064	25,877
Progress Energy [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	28,689	28,347
Generation Facilities To Be Retired Net	$ 531	548
Progress Energy [Member] | Generation Facilities To Be Retired [Member] | Crystal River Units 1 and 2 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	873
Remaining net book value (in millions)	$ 128
Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	17,768	17,720
Generation Facilities To Be Retired Net	531	548
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	$ 10,918	10,623
Duke Energy Florida [Member] | Generation Facilities To Be Retired [Member] | Crystal River Units 1 and 2 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	873
Remaining net book value (in millions)	$ 128
Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	5,288	5,243
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Remaining net book value (in millions)	9,505	$ 9,523
Generation Facilities To Be Retired Net	113
Duke Energy Indiana [Member] | Wabash River Unit 6 [Member]
Public Utilities, General Disclosures [Line Items]
Generation Facilities To Be Retired Net	$ 113
Duke Energy Indiana [Member] | Generation Facilities To Be Retired [Member] | Wabash River Unit 6 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	318
Remaining net book value (in millions)	$ 35
Duke Energy Indiana [Member] | Generation Facilities To Be Retired [Member] | Gallagher Units 2 and 4 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	280
Remaining net book value (in millions)	$ 137