Risk Management, Derivative Instruments and Hedging Activities (Cash Flow Hedges - Location and Amount of PreTax Recognized in Comprehensive Income) (Details) (Designated As Hedging Instrument [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]
Amount of pretax gains (losses) recorded in AOCI	$ 58	$ (44)	$ 72	$ (26)
Total pretax gains and (losses) reclassified from AOCI into earnings		(1)	(1)	(2)
Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gains (losses) recorded in AOCI	58	(44)	71	(26)
Total pretax gains and (losses) reclassified from AOCI into earnings		(1)	(1)	(2)
Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gains (losses) recorded in AOCI			1
Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gains (losses) recorded in AOCI		(14)	1	(10)
Total pretax gains and (losses) reclassified from AOCI into earnings		(6)		(10)
Progress Energy [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gains (losses) recorded in AOCI		(14)		(10)
Total pretax gains and (losses) reclassified from AOCI into earnings		(6)		(10)
Progress Energy [Member] | Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on price risk cash flow derivatives, before tax			1
Duke Energy Progress [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gains (losses) recorded in AOCI		(12)		(7)
Total pretax gains and (losses) reclassified from AOCI into earnings		(2)		(5)
Duke Energy Progress [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gains (losses) recorded in AOCI		(12)		(7)
Total pretax gains and (losses) reclassified from AOCI into earnings		$ (2)		$ (5)