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		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	$ (78)	$ (190)	$ (195)	$ (154)
Pretax gains (losses) recognized as regulatory assets or liabilities	(11)	80	27	92
Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	(29)	61	(34)	61
Commodity Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	6	12	10	34
Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	3	(22)	10	(22)
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	(7)	(28)	(15)	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	(68)	(135)	(157)	(135)
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	(2)		(20)
Commodity Contracts [Member] | Other Income And Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities		(1)		(1)
Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	12	7	51	(3)
Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	(4)	(4)	(13)	(4)
Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(69)	(148)	(160)	(408)
Pretax gains (losses) recognized as regulatory assets or liabilities	(27)	62	(21)	(106)
Progress Energy [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	(31)	60	(34)	(108)
Progress Energy [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	3	(9)	10	(9)
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	(68)	(135)	(157)	(395)
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	2	13	2
Progress Energy [Member] | Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	(4)	(4)	(13)	(4)
Duke Energy Progress [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(24)	(47)	(52)	(112)
Pretax gains (losses) recognized as regulatory assets or liabilities	(8)	17	(8)	(32)
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	(11)	15	(18)	(34)
Duke Energy Progress [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	3	(9)	10	(9)
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	(24)	(35)	(53)	(100)
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	2	10	2
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)	(9)	(3)
Duke Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(46)	(101)	(108)	(296)
Pretax gains (losses) recognized as regulatory assets or liabilities	(18)	45	(13)	(74)
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	(19)	45	(16)	(74)
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	(45)	(100)	(105)	(295)
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		3
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)	(3)	(1)
Duke Energy Ohio [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	3	(42)	(29)	32
Pretax gains (losses) recognized as regulatory assets or liabilities			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	5	(42)	(8)	33
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	(2)		(20)
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			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)
Duke Energy Indiana [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings			1	2
Pretax gains (losses) recognized as regulatory assets or liabilities	14	15	44	28
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	11
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		6	10	33
Duke Energy Indiana [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities			1
Duke Energy Indiana [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				2
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	$ 6	$ 4	$ 34	$ (5)