Derivatives and Hedging (Undesignated Contracts - Location and Amount of PreTax Gains and (Losses) Recognized in Income or As Regulatory Assets or Liabilities) (Details) (Not Designated as Hedging Instrument [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	$ (269)	$ 22	$ (529)	$ (117)
Pretax gains (losses) recognized as regulatory assets or liabilities	13	(75)	42	38
Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	1	(110)	(1)	(5)
Commodity Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	(28)	9	(1)	4
Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	3	1	(1)	7
Commodity Contracts [Member] | Revenue Non Regulated Electric Natural Gas And Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	(221)	74	(618)	(8)
Commodity Contracts [Member] | Fuel Used In Electric Generation And Purchased Power Regulated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	(21)	(37)	(14)	(89)
Commodity Contracts [Member] | Fuel Used In Electric Generation And Purchased Power Non Regulated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	(25)	(11)	113	(18)
Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	12	26	16	39
Interest Rate Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	28		28
Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	(5)	(5)	(9)	(9)
Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(15)	(41)	(15)	(91)
Pretax gains (losses) recognized as regulatory assets or liabilities	14	(104)	16	6
Progress Energy [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	2	(108)		(3)
Progress Energy [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	2	1	(1)	7
Progress Energy [Member] | Commodity Contracts [Member] | Fuel Used In Electric Generation And Purchased Power Regulated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	(21)	(37)	(14)	(89)
Progress Energy [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	12	4	16	9
Progress Energy [Member] | Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	4	(5)		(9)
Duke Energy Progress [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(11)	(14)	(10)	(28)
Pretax gains (losses) recognized as regulatory assets or liabilities	20	(39)	40
Duke Energy Progress [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	23	(43)	40	(7)
Duke Energy Progress [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	2	1	(1)	7
Duke Energy Progress [Member] | Commodity Contracts [Member] | Fuel Used In Electric Generation And Purchased Power Regulated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	(16)	(12)	(9)	(29)
Duke Energy Progress [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	(3)	4		7
Duke Energy Progress [Member] | Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	3	(3)		(6)
Duke Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(5)	(26)	(6)	(62)
Pretax gains (losses) recognized as regulatory assets or liabilities	(6)	(65)	(24)	5
Duke Energy Florida [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	(5)	(66)	(24)	3
Duke Energy Florida [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities
Duke Energy Florida [Member] | Commodity Contracts [Member] | Fuel Used In Electric Generation And Purchased Power Regulated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	(6)	(25)	(6)	(60)
Duke Energy Florida [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	(1)	1		2
Duke Energy Florida [Member] | Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	1	(1)		(2)
Duke Energy Ohio [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(274)	66	(585)	(32)
Pretax gains (losses) recognized as regulatory assets or liabilities	3	2	5	3
Duke Energy Ohio [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities			(1)
Duke Energy Ohio [Member] | Commodity Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	(3)
Duke Energy Ohio [Member] | Commodity Contracts [Member] | Revenue Non Regulated Electric Natural Gas And Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	(248)	78	(697)	(13)
Duke Energy Ohio [Member] | Commodity Contracts [Member] | Fuel Used In Electric Generation And Purchased Power Regulated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	(25)	(11)	113	(18)
Duke Energy Ohio [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities		2		3
Duke Energy Ohio [Member] | Interest Rate Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	6		6
Duke Energy Ohio [Member] | Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	$ (1)	$ (1)	$ (1)	$ (1)