Derivatives and Hedging (Location and Fair Value Amounts of Derivatives Reflected in the Condensed Consolidated Balance Sheets) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	$ 803	$ 461
Location and fair value amounts of derivatives (Liability)	1,012	636
Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	454	214
Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	338	233
Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	606	322
Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	399	299
Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	21	27
Location and fair value amounts of derivatives (Liability)	32	23
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	21	27
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	16	18
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	15	4
Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Nondesignated [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	782	434
Location and fair value amounts of derivatives (Liability)	980	613
Nondesignated [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Nondesignated [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	4
Nondesignated [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	27	201
Location and fair value amounts of derivatives (Liability)	7	158
Nondesignated [Member] | Commodity Contracts [Member] | Current Assets, Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	9
Location and fair value amounts of derivatives (Liability)	1
Nondesignated [Member] | Commodity Contracts [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	215
Location and fair value amounts of derivatives (Liability)		131
Nondesignated [Member] | Commodity Contracts [Member] | Investments And Other Assets, Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	312
Location and fair value amounts of derivatives (Liability)	257
Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	22	13
Location and fair value amounts of derivatives (Liability)	116	153
Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities, Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	398
Location and fair value amounts of derivatives (Liability)	463
Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4	5
Location and fair value amounts of derivatives (Liability)	92	166
Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits and Other Liabilities Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3
Location and fair value amounts of derivatives (Liability)	39
Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	36	20
Location and fair value amounts of derivatives (Liability)	190	204
Progress Energy [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	32	15
Progress Energy [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4	5
Progress Energy [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	108	107
Progress Energy [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	82	93
Progress Energy [Member] | Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	5
Progress Energy [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Progress Energy [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		4
Progress Energy [Member] | Nondesignated [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	36	20
Location and fair value amounts of derivatives (Liability)	189	199
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	10	3
Location and fair value amounts of derivatives (Liability)	6	2
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	2
Location and fair value amounts of derivatives (Liability)		1
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	22	11
Location and fair value amounts of derivatives (Liability)	102	105
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	4
Location and fair value amounts of derivatives (Liability)	81	91
Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	15	6
Location and fair value amounts of derivatives (Liability)	72	71
Duke Energy Progress [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	13	3
Duke Energy Progress [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	3
Duke Energy Progress [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	48	41
Duke Energy Progress [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	24	30
Duke Energy Progress [Member] | Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Progress [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Progress [Member] | Nondesignated [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	15	6
Location and fair value amounts of derivatives (Liability)	71	70
Duke Energy Progress [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	6
Location and fair value amounts of derivatives (Liability)	5
Duke Energy Progress [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	2
Location and fair value amounts of derivatives (Liability)		1
Duke Energy Progress [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	2
Location and fair value amounts of derivatives (Liability)	43	40
Duke Energy Progress [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	2
Location and fair value amounts of derivatives (Liability)	23	29
Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	21	14
Location and fair value amounts of derivatives (Liability)	117	129
Duke Energy Florida [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	19	12
Duke Energy Florida [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	2
Duke Energy Florida [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	59	66
Duke Energy Florida [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	58	63
Duke Energy Florida [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4	3
Location and fair value amounts of derivatives (Liability)	1	2
Duke Energy Florida [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	15	9
Location and fair value amounts of derivatives (Liability)	58	64
Duke Energy Florida [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	2
Location and fair value amounts of derivatives (Liability)	58	63
Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	732	391
Location and fair value amounts of derivatives (Liability)	778	390
Duke Energy Ohio [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	413	186
Duke Energy Ohio [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	319	205
Duke Energy Ohio [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	482	199
Duke Energy Ohio [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	296	186
Duke Energy Ohio [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Ohio [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	4
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		186
Location and fair value amounts of derivatives (Liability)		163
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Assets, Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7
Location and fair value amounts of derivatives (Liability)	1
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		202
Location and fair value amounts of derivatives (Liability)		130
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Investments And Other Assets, Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	315
Location and fair value amounts of derivatives (Liability)	256
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Location and fair value amounts of derivatives (Liability)		36
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Current Liabilities, Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	407
Location and fair value amounts of derivatives (Liability)	479
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Location and fair value amounts of derivatives (Liability)		56
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Deferred Credits and Other Liabilities Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3
Location and fair value amounts of derivatives (Liability)	$ 37