Risk Management Activities and Derivatives Transactions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011		Dec. 31, 2011
Economic derivatives
Cash collateral posted	$ 124				$ 124				$ 147
Notional MMBtu of natural gas	394,600,000				394,600,000
Notional gallons of oil	8,100,000				8,100,000
Interest rate cash flow hedges
Open interest rate hedges mandatory termination dates					1.5
After-tax (gains) losses in accumulated other comprehensive income	142				142				141
Next 12 months amount of (gains) losses to reclass to interest expense					14
Notional amount of interest rate cash flow hedges	100				100				500
Contingent features
Aggregate fair value of instruments in liability position	371				371
Additional collateral to post	247				247
Derivatives Fair Value [Abstract]
Derivative asset fair value	8				8				5
Derivative liability fair value	629				629				802
Fair Value Of Derivative Instruments Parenthetical Information
CVO's in connection with the acquisition of Florida Progress during 2000	98.6				98.6
CVO's repurchased in connection with the negotiated settlement agreement and subsequent tender offer	83.4				83.4
PEC
Economic derivatives
Cash collateral posted	21				21				24
Notional MMBtu of natural gas	119,700,000				119,700,000
Interest rate cash flow hedges
Open interest rate hedges mandatory termination dates					1.5
After-tax (gains) losses in accumulated other comprehensive income	72				72				71
Next 12 months amount of (gains) losses to reclass to interest expense					7
Notional amount of interest rate cash flow hedges	50				50				250
Contingent features
Aggregate fair value of instruments in liability position	122				122
Additional collateral to post	101				101
Derivatives Fair Value [Abstract]
Derivative asset fair value	2				2				0
Derivative liability fair value	199				199				251
PEF
Economic derivatives
Cash collateral posted	103				103				123
Notional MMBtu of natural gas	274,900,000				274,900,000
Notional gallons of oil	8,100,000				8,100,000
Interest rate cash flow hedges
Open interest rate hedges mandatory termination dates					1.5
After-tax (gains) losses in accumulated other comprehensive income	25				25				25
Next 12 months amount of (gains) losses to reclass to interest expense					2
Notional amount of interest rate cash flow hedges	50				50				50
Contingent features
Aggregate fair value of instruments in liability position	249				249
Additional collateral to post	146				146
Derivatives Fair Value [Abstract]
Derivative asset fair value	6				6				5
Derivative liability fair value	427				427				499
Derivatives designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative liability fair value	25				25				96
Derivatives designated as hedging instruments | PEC
Derivatives Fair Value [Abstract]
Derivative liability fair value	11				11				47
Derivatives designated as hedging instruments | PEF
Derivatives Fair Value [Abstract]
Derivative liability fair value	14				14				11
Derivatives not designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative asset fair value	8				8				5
Derivative liability fair value	604				604				706
Derivatives Not Designated As Hedging Instruments
Amount of Gain or (Loss) Recognized in Income on Derivatives	3		5		11		5
Derivatives not designated as hedging instruments | PEC
Derivatives Fair Value [Abstract]
Derivative asset fair value	2				2				0
Derivative liability fair value	188				188				204
Derivatives Not Designated As Hedging Instruments
Amount of Gain or (Loss) Recognized in Income on Derivatives	3		1		3		1
Derivatives not designated as hedging instruments | PEF
Derivatives Fair Value [Abstract]
Derivative asset fair value	6				6				5
Derivative liability fair value	413				413				488
Fair value of derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative asset fair value	8				8				5
Derivative liability fair value	602				602				703
Fair value of derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | PEC
Derivatives Fair Value [Abstract]
Derivative asset fair value	2				2				0
Derivative liability fair value	186				186				201
Interest rate derivatives | Derivatives designated as hedging instruments
Derivatives Designated as Hedging Instruments
Amount of Gain or (Loss) Recognized in OCI, Net of Tax on Derivatives	(8)	[1],[2],[3]	(16)	[1],[2],[3]	(6)	[1],[2],[3]	(14)	[1],[2],[3]
Amount of Gain or (Loss), Net of Tax Reclassified from Accumulated OCI into Income	(3)	[1],[2],[3]	(2)	[1],[2],[3]	(6)	[1],[2],[3]	(3)	[1],[2],[3]
Amount of Pre-tax Gain or (Loss) Recognized in Income on Derivatives	0	[2],[3],[4]	0	[2],[3],[4]	0	[2],[3],[4]	(2)	[2],[3],[4]
Interest rate derivatives | Derivatives designated as hedging instruments | PEC
Derivatives Designated as Hedging Instruments
Amount of Gain or (Loss) Recognized in OCI, Net of Tax on Derivatives	(7)	[1],[2],[3]	(6)	[1],[2],[3]	(4)	[1],[2],[3]	(5)	[1],[2],[3]
Amount of Gain or (Loss), Net of Tax Reclassified from Accumulated OCI into Income	(1)	[1],[2],[3]	(1)	[1],[2],[3]	(3)	[1],[2],[3]	(2)	[1],[2],[3]
Amount of Pre-tax Gain or (Loss) Recognized in Income on Derivatives	0	[2],[3],[4]	0	[2],[3],[4]	0	[2],[3],[4]	0	[2],[3],[4]
Interest rate derivatives | Derivatives designated as hedging instruments | PEF
Derivatives Designated as Hedging Instruments
Amount of Gain or (Loss) Recognized in OCI, Net of Tax on Derivatives	(1)	[1],[2],[5]	(5)	[1],[2],[5]	(1)	[1],[2],[5]	(5)	[1],[2],[5]
Amount of Gain or (Loss), Net of Tax Reclassified from Accumulated OCI into Income	0	[1],[2],[5]	0	[1],[2],[5]	(1)	[1],[2],[5]	0	[1],[2],[5]
Amount of Pre-tax Gain or (Loss) Recognized in Income on Derivatives	0	[2],[4],[5]	0	[2],[4],[5]	0	[2],[4],[5]	0	[2],[4],[5]
Interest rate derivatives | Derivative liabilities, current | Derivatives designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative liability fair value	11				11				76
Interest rate derivatives | Derivative liabilities, current | Derivatives designated as hedging instruments | PEC
Derivatives Fair Value [Abstract]
Derivative liability fair value	0				0				38
Interest rate derivatives | Derivative liabilities, current | Derivatives designated as hedging instruments | PEF
Derivatives Fair Value [Abstract]
Derivative liability fair value	11				11				0
Interest rate derivatives | Derivative liabilities, long-term | Derivatives designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative liability fair value	11				11				17
Interest rate derivatives | Derivative liabilities, long-term | Derivatives designated as hedging instruments | PEF
Derivatives Fair Value [Abstract]
Derivative liability fair value	0				0				8
Interest rate derivatives | Other liabilities and deferred credits | Derivatives designated as hedging instruments | PEC
Derivatives Fair Value [Abstract]
Derivative liability fair value	11				11				9
Commodity derivatives | Derivatives not designated as hedging instruments
Derivatives Not Designated As Hedging Instruments
Realized Gain or (Loss)	(155)	[6]	(76)	[6]	(260)	[6]	(128)	[6]
Unrealized Gain or (Loss)	38	[7]	(68)	[7]	(168)	[7]	(44)	[7]
Amount of Gain or (Loss) Recognized in Income on Derivatives	2	[8]	1	[8]	2	[8]	1	[8]
Commodity derivatives | Derivatives not designated as hedging instruments | PEC
Derivatives Not Designated As Hedging Instruments
Realized Gain or (Loss)	(39)	[6]	(12)	[6]	(65)	[6]	(22)	[6]
Unrealized Gain or (Loss)	10	[7]	(19)	[7]	(49)	[7]	(13)	[7]
Amount of Gain or (Loss) Recognized in Income on Derivatives	2	[8]	1	[8]	2	[8]	1	[8]
Commodity derivatives | Derivatives not designated as hedging instruments | PEF
Derivatives Not Designated As Hedging Instruments
Realized Gain or (Loss)	(116)	[6]	(64)	[6]	(195)	[6]	(106)	[6]
Unrealized Gain or (Loss)	28	[9]	(49)	[9]	(119)	[9]	(31)	[9]
Commodity derivatives | Prepayments and other current assets | Derivatives not designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative asset fair value	3	[10]			3	[10]			5	[10]
Commodity derivatives | Prepayments and other current assets | Derivatives not designated as hedging instruments | PEC
Derivatives Fair Value [Abstract]
Derivative asset fair value	1	[10]			1	[10]			0	[10]
Commodity derivatives | Prepayments and other current assets | Derivatives not designated as hedging instruments | PEF
Derivatives Fair Value [Abstract]
Derivative asset fair value	2	[10]			2	[10]			5	[10]
Commodity derivatives | Other assets and deferred debits | Derivatives not designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative asset fair value	5	[10]			5	[10]			0	[10]
Commodity derivatives | Other assets and deferred debits | Derivatives not designated as hedging instruments | PEC
Derivatives Fair Value [Abstract]
Derivative asset fair value	1	[10]			1	[10]			0	[10]
Commodity derivatives | Other assets and deferred debits | Derivatives not designated as hedging instruments | PEF
Derivatives Fair Value [Abstract]
Derivative asset fair value	4	[10]			4	[10]			0	[10]
Commodity derivatives | Derivative liabilities, current | Derivatives designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative liability fair value	2				2				2
Commodity derivatives | Derivative liabilities, current | Derivatives designated as hedging instruments | PEF
Derivatives Fair Value [Abstract]
Derivative liability fair value	2				2				2
Commodity derivatives | Derivative liabilities, current | Derivatives not designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative liability fair value	312	[10]			312	[10]			357	[10]
Commodity derivatives | Derivative liabilities, current | Derivatives not designated as hedging instruments | PEC
Derivatives Fair Value [Abstract]
Derivative liability fair value	88	[10]			88	[10]			91	[10]
Commodity derivatives | Derivative liabilities, current | Derivatives not designated as hedging instruments | PEF
Derivatives Fair Value [Abstract]
Derivative liability fair value	224	[10]			224	[10]			266	[10]
Commodity derivatives | Derivative liabilities, long-term | Derivatives designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative liability fair value	1				1				1
Commodity derivatives | Derivative liabilities, long-term | Derivatives designated as hedging instruments | PEF
Derivatives Fair Value [Abstract]
Derivative liability fair value	1				1				1
Commodity derivatives | Derivative liabilities, long-term | Derivatives not designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative liability fair value	287	[10]			287	[10]			332	[10]
Commodity derivatives | Derivative liabilities, long-term | Derivatives not designated as hedging instruments | PEF
Derivatives Fair Value [Abstract]
Derivative liability fair value	189	[10]			189	[10]			222	[10]
Commodity derivatives | Other liabilities and deferred credits | Derivatives not designated as hedging instruments | PEC
Derivatives Fair Value [Abstract]
Derivative liability fair value	98	[10]			98	[10]			110	[10]
CVOs | Derivatives not designated as hedging instruments
Derivatives Not Designated As Hedging Instruments
Amount of Gain or (Loss) Recognized in Income on Derivatives	0	[8]	4	[8]	8	[8]	4	[8]
CVOs | Other liabilities, current | Derivatives not designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative liability fair value	0	[11]			0	[11]			14	[11]
CVOs | Other liabilities and deferred credits | Derivatives not designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative liability fair value	3	[11]			3	[11]			0	[11]
Fair value loss transition adjustment | Derivatives not designated as hedging instruments
Derivatives Not Designated As Hedging Instruments
Amount of Gain or (Loss) Recognized in Income on Derivatives	1	[8]	0	[8]	1	[8]	0	[8]
Fair value loss transition adjustment | Derivatives not designated as hedging instruments | PEC
Derivatives Not Designated As Hedging Instruments
Amount of Gain or (Loss) Recognized in Income on Derivatives	1	[8]	0	[8]	1	[8]	0	[8]
Fair value loss transition adjustment | Derivative liabilities, current | Derivatives not designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative liability fair value	1				1				1
Fair value loss transition adjustment | Derivative liabilities, current | Derivatives not designated as hedging instruments | PEC
Derivatives Fair Value [Abstract]
Derivative liability fair value	1				1				1
Fair value loss transition adjustment | Derivative liabilities, long-term | Derivatives not designated as hedging instruments
Derivatives Fair Value [Abstract]
Derivative liability fair value	1				1				2
Fair value loss transition adjustment | Other liabilities and deferred credits | Derivatives not designated as hedging instruments | PEC
Derivatives Fair Value [Abstract]
Derivative liability fair value	$ 1				$ 1				$ 2

[1] Effective portion.

[2] Amounts in accumulated OCI related to terminated hedges are reclassified to earnings as the interest expense is recorded. The effective portion of the hedges will be amortized to interest expense over the term of the related debt.

[3] Amounts recorded in the Consolidated Statements of Comprehensive Income are classified in interest charges.

[4] Related to ineffective portion and amount excluded from effectiveness testing.

[5] Amounts recorded in the Statements of Comprehensive Income are classified in interest charges.

[6] After settlement of the derivatives and the fuel is consumed, gains or losses are passed through the fuel cost-recovery clause.

[7] Amounts are recorded in regulatory liabilities and assets, respectively, on the Consolidated Balance Sheets until derivatives are settled.

[8] Amounts recorded in the Consolidated Statements of Comprehensive Income are classified in other, net.

[9] Amounts are recorded in regulatory liabilities and assets, respectively, on the Balance Sheets until derivatives are settled.

[10] Substantially all of these contracts receive regulatory treatment.

[11] As discussed in Note 16 in the 2011 Form 10-K, the Parent issued 98.6 million CVOs in connection with the acquisition of Florida Progress during 2000. Through a negotiated settlement agreement and subsequent tender offer between October 2011 and February 2012, we repurchased and continue to hold 83.4 million CVOs.