Risk Management, Derivative Instruments and Hedging Activities (Cash Flow Hedges - Location and Amount of PreTax Recognized in Comprehensive Income) (Details) (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]
Total pretax gains and (losses) reclassified from AOCI into earnings	$ 379	$ 401	$ 1,127	$ 857
Designated As Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recorded in AOCI		(3)	72	(29)
Pretax gains and (losses) recognized in earnings on derivatives		2	(2)
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recorded in AOCI - interest rate contracts		(4)	71	(30)
Total pretax gains and (losses) reclassified from AOCI into earnings		2	(2)
Designated As Hedging Instrument [Member] | Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recorded in AOCI - commodity contracts		1	1	1
Duke Energy Carolinas [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recorded in AOCI - interest rate contracts				23
Total pretax gains and (losses) reclassified from AOCI into earnings	82	95	255	285
Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains and (losses) reclassified from AOCI into earnings	162	182	520	560
Progress Energy [Member] | Designated As Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recorded in AOCI		1	1	(10)
Pretax gains and (losses) recognized in earnings on derivatives	(5)	(2)	(5)	(12)
Progress Energy [Member] | Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recorded in AOCI - interest rate contracts				(11)
Total pretax gains and (losses) reclassified from AOCI into earnings	(5)	(2)	(5)	(12)
Progress Energy [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recorded in AOCI - commodity contracts		1	1	1
Duke Energy Progress [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains and (losses) reclassified from AOCI into earnings	52	52	147	156
Duke Energy Progress [Member] | Designated As Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recorded in AOCI				(7)
Pretax gains and (losses) recognized in earnings on derivatives				(5)
Duke Energy Progress [Member] | Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recorded in AOCI - interest rate contracts				(7)
Total pretax gains and (losses) reclassified from AOCI into earnings				(5)
Duke Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains and (losses) reclassified from AOCI into earnings	46	62	138	194
Duke Energy Ohio [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains and (losses) reclassified from AOCI into earnings	14	21	50	70
Duke Energy Indiana [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains and (losses) reclassified from AOCI into earnings	$ 43	$ 35	$ 127	$ 105