Derivatives and Hedging (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	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	$ (264)	$ (187)	$ (60)
Pretax gains (losses) recognized as regulatory assets or liabilities	80	44	(209)
Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	10	(2)	(1)
Commodity Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	15	36	17
Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	11	(23)
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	43	38	(59)
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	(200)	(194)
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	(100)	2	(1)
Commodity Contracts [Member] | Other Income And Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities		(2)
Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	55	10	(165)
Interest Rate Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities			(60)
Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	(18)	(8)
Duke Energy Carolinas [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(12)	(12)
Pretax gains (losses) recognized as regulatory assets or liabilities			(154)
Duke Energy Carolinas [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	(12)	(12)
Duke Energy Carolinas [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities			(94)
Duke Energy Carolinas [Member] | Interest Rate Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities			(60)
Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(206)	(466)	(355)
Pretax gains (losses) recognized as regulatory assets or liabilities	28	(165)	(502)
Progress Energy [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	10	(171)	(502)
Progress Energy [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	11	(11)	1
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	(200)	(454)	(297)
Progress Energy [Member] | Commodity Contracts [Member] | Other Income And Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities		7	(59)
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	18	6
Progress Energy [Member] | Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	(17)	(8)
Duke Energy Progress [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(73)	(132)	(59)
Pretax gains (losses) recognized as regulatory assets or liabilities	7	(49)	(140)
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	(6)	(55)	(140)
Duke Energy Progress [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - commodities	11	(11)	1
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	(71)	(115)	(60)
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	13	6
Duke Energy Progress [Member] | Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	(13)	(6)
Duke Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(134)	(341)	(237)
Pretax gains (losses) recognized as regulatory assets or liabilities	21	(116)	(362)
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	16	(116)	(362)
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	(129)	(339)	(237)
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	5
Duke Energy Florida [Member] | Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings - interest	(5)	(2)
Duke Energy Ohio [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	(57)	77	(28)
Pretax gains (losses) recognized as regulatory assets or liabilities	4	1	(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		2	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		(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	44	76	(26)
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	(100)	2	(1)
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	4		(4)
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)
Duke Energy Indiana [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized in earnings	1
Pretax gains (losses) recognized as regulatory assets or liabilities	50	41	(52)
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	0	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	16	35	17
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] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	$ 34	$ 4	$ (67)