Derivatives and Hedging (Cash Flow Hedges - Location and Amount of PreTax Recognized in Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense	$ (413)	$ (381)	$ (819)	$ (748)
Designated As Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Pretax Gains (Losses) Recorded in AOCI	(11)	58	(9)	72
Total Pretax Gains (Losses) Reclassified from AOCI into Earnings	(4)		(5)	(1)
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax Gains (Losses) Recorded in AOCI	(11)	58	(9)	71
Interest expense	(4)		(5)	(1)
Designated As Hedging Instrument [Member] | Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax Gains (Losses) Recorded in AOCI				1
Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense	(167)	(160)	(336)	(358)
Duke Energy Progress [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense	(58)	(47)	(115)	(95)
Duke Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense	(50)	(43)	(99)	(92)
Duke Energy Ohio [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense	$ (29)	$ (18)	$ (51)	$ (36)