Derivatives and Hedging (Location and Fair Value Amounts of Derivatives Reflected in the Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	$ 26	$ 351
Location and fair value amounts of derivatives (Liability)	419	909
Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	45	19
Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	11	2
Location and fair value amounts of derivatives (Liability)	322	371
Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Location and fair value amounts of derivatives (Liability)	98	132
Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	2
Location and fair value amounts of derivatives (Liability)	216	239
Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	341
Location and fair value amounts of derivatives (Liability)	7	473
Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	14
Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	18	210
Current Assets, Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	2
Current Assets, Other [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Current Assets, Other [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	2
Current Assets, Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	204
Current Assets, Other [Member] | Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	14
Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	8	136
Investments And Other Assets, Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4
Investments And Other Assets, Other [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4
Investments And Other Assets, Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		137
Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	271	573
Current Liabilities, Other [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	32	14
Current Liabilities, Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	225	289
Current Liabilities, Other [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	77	109
Current Liabilities, Other [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	145	180
Current Liabilities, Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	257
Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	148	319
Deferred Credits And Other Liabilities, Other [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	13	5
Deferred Credits And Other Liabilities, Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	97	82
Deferred Credits And Other Liabilities, Other [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	21	23
Deferred Credits And Other Liabilities, Other [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	71	59
Deferred Credits And Other Liabilities, Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	6	216
Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	16	339
Location and fair value amounts of derivatives (Liability)	356	859
Commodity Contract [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	40	19
Commodity Contract [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)	314	369
Commodity Contract [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	93	132
Commodity Contract [Member] | Duke 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)	216	237
Commodity Contract [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	341
Location and fair value amounts of derivatives (Liability)		467
Commodity Contract [Member] | Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	14
Commodity Contract [Member] | Designated as Hedging Instrument [Member] | Current Liabilities, Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		1
Commodity Contract [Member] | Designated as Hedging Instrument [Member] | Current Liabilities, Other [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		1
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	12
Location and fair value amounts of derivatives (Liability)	256
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	32
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1
Location and fair value amounts of derivatives (Liability)	222
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	77
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1
Location and fair value amounts of derivatives (Liability)	145
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member] | Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4
Location and fair value amounts of derivatives (Liability)	100
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Noncurrent [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	8
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Noncurrent [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4
Location and fair value amounts of derivatives (Liability)	92
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Noncurrent [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	16
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Noncurrent [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4
Location and fair value amounts of derivatives (Liability)	71
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		18
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Assets, Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Assets, Other [Member] | Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		14
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Assets, Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		15
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Assets, Assets Held For Sale [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		28
Location and fair value amounts of derivatives (Liability)		4
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		3
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Investments And Other Assets, Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		15
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Investments And Other Assets, Assets Held For Sale [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		26
Location and fair value amounts of derivatives (Liability)		4
Commodity Contract [Member] | Not Designated as Hedging Instrument [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)		307
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities, Other [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		14
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities, Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		288
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities, Other [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		108
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities, Other [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		180
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities, Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		174
Location and fair value amounts of derivatives (Liability)		253
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities, Assets Held For Sale [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		175
Location and fair value amounts of derivatives (Liability)		252
Commodity Contract [Member] | Not Designated as Hedging Instrument [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)		91
Commodity Contract [Member] | Not Designated as Hedging Instrument [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)		5
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Deferred Credits And Other Liabilities, Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		80
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Deferred Credits And Other Liabilities, Other [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		23
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Deferred Credits And Other Liabilities, Other [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		57
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Deferred Credits and Other Liabilities, Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		111
Location and fair value amounts of derivatives (Liability)		208
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Deferred Credits and Other Liabilities, Assets Held For Sale [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		111
Location and fair value amounts of derivatives (Liability)		207
Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	10	12
Location and fair value amounts of derivatives (Liability)	63	50
Interest Rate Contract [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5
Interest Rate Contract [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	6	2
Location and fair value amounts of derivatives (Liability)	8	2
Interest Rate Contract [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Location and fair value amounts of derivatives (Liability)	5
Interest Rate Contract [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	2
Location and fair value amounts of derivatives (Liability)		2
Interest Rate Contract [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	7	6
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	11
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4
Location and fair value amounts of derivatives (Liability)	33
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		10
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		13
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		29
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	6
Location and fair value amounts of derivatives (Liability)	4
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	6
Location and fair value amounts of derivatives (Liability)	3
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Current [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Noncurrent [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	15
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Noncurrent [Member] | Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Noncurrent [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Noncurrent [Member] | Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Noncurrent [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	$ 6
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Assets, Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Assets, Other [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		1
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities, Other [Member] | Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		1
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		7
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Deferred Credits And Other Liabilities, Other [Member] | Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		2
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Deferred Credits And Other Liabilities, Other [Member] | Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		2
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [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)		$ 5