Regulatory Matters (Schedule of Net Carrying Value Of Facilities As Well As the Remaining Non-current Regulatory Assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 MW	Dec. 31, 2013
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	$ 70,046	$ 69,490
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Megawatt of potential plants to be retired, in megawatts	1,704
Net property, plant and equipment	239
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	24,672	23,012
Progress Energy [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	25,144	23,382
Progress Energy [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Megawatt of potential plants to be retired, in megawatts	873
Net property, plant and equipment	114
Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	15,186	13,650
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	9,955	9,611
Duke Energy Florida [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Megawatt of potential plants to be retired, in megawatts	873
Net property, plant and equipment	114
Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	4,937	8,235
Duke Energy Ohio [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Megawatt of potential plants to be retired, in megawatts	163
Net property, plant and equipment	9
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	8,815	8,576
Duke Energy Indiana [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Megawatt of potential plants to be retired, in megawatts	668
Net property, plant and equipment	$ 116