Risk Management, Derivative Instruments And Hedging Activities (Cash Flow Hedges - Location And Amount Of Pre-Tax Recognized In Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gains (losses) recorded in AOCI	$ (22)	$ (88)	$ 2
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	2	(5)	(3)
Duke Energy Carolinas [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	(3)	(5)	(6)
Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gains (losses) recorded in AOCI	(10)	(144)	(57)
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	(14)	(13)	(11)
Losses Reclassified from AOCI to Regulatory Assets or Liabilities	(159)
Progress Energy Carolinas [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gains (losses) recorded in AOCI	(7)	(70)	(16)
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	(5)	(7)	(7)
Losses Reclassified from AOCI to Regulatory Assets or Liabilities	(117)
Progress Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gains (losses) recorded in AOCI	(1)	(38)	(11)
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	(2)	(1)
Losses Reclassified from AOCI to Regulatory Assets or Liabilities	(42)
Duke Energy Indiana [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	3	2	3
Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gains (losses) recorded in AOCI	(23)	(88)	2
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	2	(5)	(5)
Interest Rate Contract [Member] | Duke Energy Carolinas [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	(3)	(5)	(6)
Interest Rate Contract [Member] | Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gains (losses) recorded in AOCI	(11)	(141)	(57)
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	(14)	(13)	(11)
Losses Reclassified from AOCI to Regulatory Assets or Liabilities	(159)
Interest Rate Contract [Member] | Progress Energy Carolinas [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gains (losses) recorded in AOCI	(7)	(70)	(16)
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	(5)	(7)	(7)
Losses Reclassified from AOCI to Regulatory Assets or Liabilities	(117)
Interest Rate Contract [Member] | Progress Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gains (losses) recorded in AOCI	(2)	(35)	(11)
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	(2)	(1)
Losses Reclassified from AOCI to Regulatory Assets or Liabilities	(42)
Interest Rate Contract [Member] | Duke Energy Indiana [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	3	2	3
Commodity Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gains (losses) recorded in AOCI	1
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings			2
Commodity Contract [Member] | Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gains (losses) recorded in AOCI	1	(3)
Commodity Contract [Member] | Progress Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gains (losses) recorded in AOCI	$ 1	$ (3)