Risk Management, Derivative Instruments and Hedging Activities (Undesignated Contracts - Location and Amount of PreTax Gains and (Losses) Recognized in Income or As Regulatory Assets or Liabilities) (Details) (Nondesignated [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	$ 22		$ (117)	$ 36
Pretax gains (losses) recognized as regulatory assets or liabilities	(75)	(14)	38	12
Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	(110)	1	(5)
Commodity Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	9	17	4	22
Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	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	74		(8)	36
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	(37)		(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	(11)		(18)
Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	26	(32)	39	(10)
Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	(5)		(9)
Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(41)	(152)	(91)	(249)
Pretax gains (losses) recognized as regulatory assets or liabilities	(104)	38	6	(168)
Progress Energy [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	(108)	38	(3)	(168)
Progress Energy [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	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	(37)	(155)	(89)	(260)
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	4		9
Progress Energy [Member] | Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	(5)		(9)
Progress Energy [Member] | CVOs [Member] | Other Income And Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings		3		11
Duke Energy Progress [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(14)	(36)	(28)	(62)
Pretax gains (losses) recognized as regulatory assets or liabilities	(39)	10		(49)
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	(43)	10	(7)	(49)
Duke Energy Progress [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	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	(12)	(39)	(29)	(65)
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	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)		(6)
Duke Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(26)	(116)	(62)	(195)
Pretax gains (losses) recognized as regulatory assets or liabilities	(65)	28	5	(119)
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	(66)	28	3	(119)
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	(25)	(116)	(60)	(195)
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		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)		(2)
Duke Energy Ohio [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	66	3	(32)	74
Pretax gains (losses) recognized as regulatory assets or liabilities	2	(1)	3	(1)
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				(2)
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				1
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	78	4	(13)	75
Duke Energy Ohio [Member] | 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	(11)		(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	(1)	3
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)
Duke Energy Indiana [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	18	(10)	30	15
Duke Energy Indiana [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	(2)	2	(2)	2
Duke Energy Indiana [Member] | Commodity Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities		18	4	22
Duke Energy Indiana [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	$ 20	$ (30)	$ 28	$ (9)