Regulatory Matters (Schedule of Net Carrying Value Of Facilities) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) MW	Dec. 31, 2015 USD ($)
Public Utilities, General Disclosures [Line Items]
Regulatory assets	$ 13,901	$ 12,250
Net property, plant and equipment	82,520	73,779
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	3,397	3,071
Net property, plant and equipment	26,762	25,877
Progress Energy [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	6,123	5,797
Net property, plant and equipment	30,181	28,347
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	2,693	2,823
Net property, plant and equipment	11,790	10,623
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	1,222	818
Net property, plant and equipment	9,924	9,523
Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	3,431	2,974
Net property, plant and equipment	$ 18,387	$ 17,720
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,738
Net property, plant and equipment	$ 424
Generation Facilities To Be Retired [Member] | Duke Energy Carolinas [Member] | Allen Steam Station Units 1-3 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	585
Net property, plant and equipment	$ 168
Generation Facilities To Be Retired [Member] | Progress Energy [Member] | Crystal River Units 1 and 2 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	873
Net property, plant and equipment	$ 120
Generation Facilities To Be Retired [Member] | Duke Energy Florida [Member] | Crystal River Units 1 and 2 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	873
Net property, plant and equipment	$ 120
Generation Facilities To Be Retired [Member] | Duke Energy Indiana [Member] | Gallagher Units 2 and 4 [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	280
Net property, plant and equipment	$ 136