Risk Management, Derivative Instruments And Hedging Activities (Location And Fair Value Amounts Of Derivatives Reflected In The Condensed Consolidated Balance Sheets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	$ 264	$ 283
Location and fair value amounts of derivatives (Liability)	917	473
Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Location and fair value amounts of derivatives (Liability)	12
Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	11	5
Location and fair value amounts of derivatives (Liability)	440	799
Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Location and fair value amounts of derivatives (Liability)	166	248
Progress Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	9	5
Location and fair value amounts of derivatives (Liability)	270	499
Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	220	271
Location and fair value amounts of derivatives (Liability)	199	245
Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	10	4
Location and fair value amounts of derivatives (Liability)	63	68
Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	9	6
Location and fair value amounts of derivatives (Liability)	119	87
Designated As Hedging Instrument [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Designated As Hedging Instrument [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	3	96
Designated As Hedging Instrument [Member] | Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	2	47
Designated As Hedging Instrument [Member] | Progress Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	11
Designated As Hedging Instrument [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	5
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Current Assets Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	4
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Current Assets Other [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Current Assets Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	3
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Investments And Other Assets Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	2
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Investments And Other Assets Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Current Liabilities Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	81	11
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Current Liabilities Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		76
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Current Liabilities Other [Member] | Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		38
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Deferred Credits And Other Liabilities Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	35	76
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		17
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		9
Designated As Hedging Instrument [Member] | Interest Rate Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Progress Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		8
Designated As Hedging Instrument [Member] | Commodity Contract [Member] | Current Liabilities Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	2
Designated As Hedging Instrument [Member] | Commodity Contract [Member] | Current Liabilities Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	2	2
Designated As Hedging Instrument [Member] | Commodity Contract [Member] | Current Liabilities Other [Member] | Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1
Designated As Hedging Instrument [Member] | Commodity Contract [Member] | Current Liabilities Other [Member] | Progress Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	2
Designated As Hedging Instrument [Member] | Commodity Contract [Member] | Deferred Credits And Other Liabilities Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1
Designated As Hedging Instrument [Member] | Commodity Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Designated As Hedging Instrument [Member] | Commodity Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1
Designated As Hedging Instrument [Member] | Commodity Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Progress Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		1
Nondesignated [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	255	277
Location and fair value amounts of derivatives (Liability)	798	386
Nondesignated [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	12
Nondesignated [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	11	5
Location and fair value amounts of derivatives (Liability)	437	703
Nondesignated [Member] | Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Location and fair value amounts of derivatives (Liability)	164	201
Nondesignated [Member] | Progress Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	9	5
Location and fair value amounts of derivatives (Liability)	269	488
Nondesignated [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	218	266
Location and fair value amounts of derivatives (Liability)	199	245
Nondesignated [Member] | Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	10	4
Location and fair value amounts of derivatives (Liability)	63	68
Nondesignated [Member] | Interest Rate Contract [Member] | Current Liabilities Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	76	2
Nondesignated [Member] | Interest Rate Contract [Member] | Current Liabilities Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	11
Nondesignated [Member] | Interest Rate Contract [Member] | Current Liabilities Other [Member] | Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	11
Nondesignated [Member] | Interest Rate Contract [Member] | Current Liabilities Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Nondesignated [Member] | Interest Rate Contract [Member] | Current Liabilities Other [Member] | Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	63
Nondesignated [Member] | Interest Rate Contract [Member] | Deferred Credits And Other Liabilities Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	8	75
Nondesignated [Member] | Interest Rate Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	7	8
Nondesignated [Member] | Interest Rate Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		66
Nondesignated [Member] | Commodity Contract [Member] | Current Assets Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	41	81
Location and fair value amounts of derivatives (Liability)	2	31
Nondesignated [Member] | Commodity Contract [Member] | Current Assets Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3
Nondesignated [Member] | Commodity Contract [Member] | Current Assets Other [Member] | Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1
Nondesignated [Member] | Commodity Contract [Member] | Current Assets Other [Member] | Progress Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Nondesignated [Member] | Commodity Contract [Member] | Current Assets Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	31	79
Location and fair value amounts of derivatives (Liability)	4	39
Nondesignated [Member] | Commodity Contract [Member] | Current Assets Other [Member] | Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	10	4
Nondesignated [Member] | Commodity Contract [Member] | Investments And Other Assets Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	106	35
Location and fair value amounts of derivatives (Liability)	50	17
Nondesignated [Member] | Commodity Contract [Member] | Investments And Other Assets Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	8
Nondesignated [Member] | Commodity Contract [Member] | Investments And Other Assets Other [Member] | Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1
Nondesignated [Member] | Commodity Contract [Member] | Investments And Other Assets Other [Member] | Progress Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7
Nondesignated [Member] | Commodity Contract [Member] | Investments And Other Assets Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	81	29
Location and fair value amounts of derivatives (Liability)	51	18
Nondesignated [Member] | Commodity Contract [Member] | Current Liabilities Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	106	136
Location and fair value amounts of derivatives (Liability)	407	168
Nondesignated [Member] | Commodity Contract [Member] | Current Liabilities Other [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	6
Nondesignated [Member] | Commodity Contract [Member] | Current Liabilities Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		5
Location and fair value amounts of derivatives (Liability)	231	371
Nondesignated [Member] | Commodity Contract [Member] | Current Liabilities Other [Member] | Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	85	91
Nondesignated [Member] | Commodity Contract [Member] | Current Liabilities Other [Member] | Progress Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		5
Location and fair value amounts of derivatives (Liability)	146	266
Nondesignated [Member] | Commodity Contract [Member] | Current Liabilities Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	106	136
Location and fair value amounts of derivatives (Liability)	132	146
Nondesignated [Member] | Commodity Contract [Member] | Current Liabilities Other [Member] | Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		2
Nondesignated [Member] | Commodity Contract [Member] | Deferred Credits And Other Liabilities Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	25
Location and fair value amounts of derivatives (Liability)	255	93
Nondesignated [Member] | Commodity Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	6
Nondesignated [Member] | Commodity Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	195	332
Nondesignated [Member] | Commodity Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Progress Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	68	110
Nondesignated [Member] | Commodity Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Progress Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	123	222
Nondesignated [Member] | Commodity Contract [Member] | Deferred Credits And Other Liabilities Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		22
Location and fair value amounts of derivatives (Liability)	$ 4	$ 33