Derivatives and Hedging (Cash Flow Hedges - Location and Amount of PreTax Recognized in Comprehensive Income) (Details) (Designated As Hedging Instrument [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recorded in AOCI	$ (39)	$ 80	$ (22)
Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recorded in AOCI	(39)	79	(23)
Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recorded in AOCI		1	1
Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recorded in AOCI		1	(10)
Progress Energy [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recorded in AOCI			(11)
Progress Energy [Member] | Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recorded in AOCI		1	1
Duke Energy Progress [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recorded in AOCI			(7)
Duke Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recorded in AOCI		1	(1)
Duke Energy Florida [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recorded in AOCI			(2)
Duke Energy Florida [Member] | Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recorded in AOCI		1	1
Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(7)	(2)	2
Interest Rate Contracts [Member] | Duke Energy Carolinas [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(3)	(3)	(3)
Interest Rate Contracts [Member] | Progress Energy [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(13)		(14)
Interest Rate Contracts [Member] | Duke Energy Progress [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net			(5)
Interest Rate Contracts [Member] | Duke Energy Florida [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(2)		(2)
Interest Rate Contracts [Member] | Duke Energy Indiana [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net		3	3
Regulatory Asset [Member] | Interest Rate Contracts [Member] | Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities			(159)
Regulatory Asset [Member] | Interest Rate Contracts [Member] | Duke Energy Progress [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities			(117)
Regulatory Asset [Member] | Interest Rate Contracts [Member] | Duke Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities			$ (42)