Fair Value Disclosures - (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Additional Fair Value Elements [Abstract]
Carrying amount of long term debt including current maturities	$ 13,937,000,000		$ 13,937,000,000		$ 12,941,000,000
Schedule Of Available For Sale Securities [Abstract]
Fair Value	1,757,000,000		1,757,000,000		1,630,000,000
Unrealized Losses	31,000,000		31,000,000		31,000,000
Unrealized Gains	510,000,000		510,000,000		444,000,000
Aggregate fair value of investments related to unrealized losses
Aggregate fair value of investments related to unrealized losses	151,000,000		151,000,000		136,000,000
Fair value of available for sale debt securities by contractual maturity
Due in one year or less	54,000,000		54,000,000
Due after one through five years	213,000,000		213,000,000
Due after five through 10 years	156,000,000		156,000,000
Due after 10 years	107,000,000		107,000,000
Total	530,000,000		530,000,000
Sales of available for sale securities
Proceeds	215,000,000	1,448,000,000	519,000,000	3,192,000,000
Realized gains	8,000,000	6,000,000	15,000,000	14,000,000
Realized losses	1,000,000	6,000,000	0	10,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	1,757,000,000		1,757,000,000		1,647,000,000
Other marketable securities
Total assets	1,781,000,000		1,781,000,000		1,672,000,000
Derivatives
Total liabilities	627,000,000		627,000,000		799,000,000
PEC
Additional Fair Value Elements [Abstract]
Carrying amount of long term debt including current maturities	5,190,000,000		5,190,000,000		4,193,000,000
Schedule Of Available For Sale Securities [Abstract]
Fair Value	1,167,000,000		1,167,000,000		1,101,000,000
Unrealized Losses	19,000,000		19,000,000		20,000,000
Unrealized Gains	328,000,000		328,000,000		287,000,000
Aggregate fair value of investments related to unrealized losses
Aggregate fair value of investments related to unrealized losses	109,000,000		109,000,000		98,000,000
Fair value of available for sale debt securities by contractual maturity
Due in one year or less	10,000,000		10,000,000
Due after one through five years	203,000,000		203,000,000
Due after five through 10 years	91,000,000		91,000,000
Due after 10 years	71,000,000		71,000,000
Total	375,000,000		375,000,000
Sales of available for sale securities
Proceeds	120,000,000	119,000,000	250,000,000	250,000,000
Realized gains	5,000,000	3,000,000	10,000,000	6,000,000
Realized losses	1,000,000	4,000,000	3,000,000	5,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	1,164,000,000		1,164,000,000		1,088,000,000
Other marketable securities
Other marketable securities	2,000,000		2,000,000		6,000,000
Total assets	1,168,000,000		1,168,000,000		1,094,000,000
Derivatives
Total liabilities	197,000,000		197,000,000		248,000,000
PEF
Additional Fair Value Elements [Abstract]
Carrying amount of long term debt including current maturities	4,482,000,000		4,482,000,000		4,482,000,000
Schedule Of Available For Sale Securities [Abstract]
Fair Value	590,000,000		590,000,000		529,000,000
Unrealized Losses	12,000,000		12,000,000		11,000,000
Unrealized Gains	182,000,000		182,000,000		157,000,000
Aggregate fair value of investments related to unrealized losses
Aggregate fair value of investments related to unrealized losses	42,000,000		42,000,000		38,000,000
Fair value of available for sale debt securities by contractual maturity
Due in one year or less	44,000,000		44,000,000
Due after one through five years	10,000,000		10,000,000
Due after five through 10 years	65,000,000		65,000,000
Due after 10 years	36,000,000		36,000,000
Total	155,000,000		155,000,000
Sales of available for sale securities
Proceeds	95,000,000	1,329,000,000	269,000,000	2,935,000,000
Realized gains	3,000,000	3,000,000	5,000,000	8,000,000
Realized losses	2,000,000	2,000,000	3,000,000	5,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	593,000,000		593,000,000		559,000,000
Other marketable securities
Other marketable securities	1,000,000		1,000,000		1,000,000
Total assets	600,000,000		600,000,000		565,000,000
Derivatives
Total liabilities	427,000,000		427,000,000		499,000,000
Common stock equity
Schedule Of Available For Sale Securities [Abstract]
Fair Value	1,109,000,000		1,109,000,000		1,033,000,000
Unrealized Losses	29,000,000		29,000,000		29,000,000
Unrealized Gains	462,000,000		462,000,000		401,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	1,109,000,000		1,109,000,000		1,033,000,000
Common stock equity | PEC
Schedule Of Available For Sale Securities [Abstract]
Fair Value	727,000,000		727,000,000		673,000,000
Unrealized Losses	19,000,000		19,000,000		20,000,000
Unrealized Gains	293,000,000		293,000,000		255,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	727,000,000		727,000,000		673,000,000
Common stock equity | PEF
Schedule Of Available For Sale Securities [Abstract]
Fair Value	382,000,000		382,000,000		360,000,000
Unrealized Losses	10,000,000		10,000,000		9,000,000
Unrealized Gains	169,000,000		169,000,000		146,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	382,000,000		382,000,000		360,000,000
Preferred stock and other equity
Schedule Of Available For Sale Securities [Abstract]
Fair Value	47,000,000		47,000,000		29,000,000
Unrealized Losses	0		0		0
Unrealized Gains	14,000,000		14,000,000		11,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	47,000,000		47,000,000		29,000,000
Preferred stock and other equity | PEC
Schedule Of Available For Sale Securities [Abstract]
Fair Value	22,000,000		22,000,000		17,000,000
Unrealized Gains	9,000,000		9,000,000		7,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	22,000,000		22,000,000		17,000,000
Preferred stock and other equity | PEF
Schedule Of Available For Sale Securities [Abstract]
Fair Value	25,000,000		25,000,000		12,000,000
Unrealized Gains	5,000,000		5,000,000		4,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	25,000,000		25,000,000		12,000,000
Corporate debt
Schedule Of Available For Sale Securities [Abstract]
Fair Value	88,000,000		88,000,000		86,000,000
Unrealized Losses	0		0		0
Unrealized Gains	7,000,000		7,000,000		6,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	88,000,000		88,000,000		86,000,000
Corporate debt | PEC
Schedule Of Available For Sale Securities [Abstract]
Fair Value	73,000,000		73,000,000		69,000,000
Unrealized Gains	6,000,000		6,000,000		5,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	73,000,000		73,000,000		69,000,000
Corporate debt | PEF
Schedule Of Available For Sale Securities [Abstract]
Fair Value	15,000,000		15,000,000		17,000,000
Unrealized Gains	1,000,000		1,000,000		1,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	15,000,000		15,000,000		17,000,000
U.S. state and municipal debt
Schedule Of Available For Sale Securities [Abstract]
Fair Value	135,000,000		135,000,000		128,000,000
Unrealized Losses	2,000,000		2,000,000		2,000,000
Unrealized Gains	9,000,000		9,000,000		7,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	135,000,000		135,000,000		128,000,000
U.S. state and municipal debt | PEC
Schedule Of Available For Sale Securities [Abstract]
Fair Value	62,000,000		62,000,000		56,000,000
Unrealized Gains	4,000,000		4,000,000		3,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	62,000,000		62,000,000		56,000,000
U.S. state and municipal debt | PEF
Schedule Of Available For Sale Securities [Abstract]
Fair Value	73,000,000		73,000,000		72,000,000
Unrealized Losses	2,000,000		2,000,000		2,000,000
Unrealized Gains	5,000,000		5,000,000		4,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	73,000,000		73,000,000		72,000,000
U.S. and foreign government debt
Schedule Of Available For Sale Securities [Abstract]
Fair Value	293,000,000		293,000,000		284,000,000
Unrealized Losses	0		0		0
Unrealized Gains	17,000,000		17,000,000		18,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	293,000,000		293,000,000		284,000,000
U.S. and foreign government debt | PEC
Schedule Of Available For Sale Securities [Abstract]
Fair Value	229,000,000		229,000,000		226,000,000
Unrealized Gains	15,000,000		15,000,000		16,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	229,000,000		229,000,000		226,000,000
U.S. and foreign government debt | PEF
Schedule Of Available For Sale Securities [Abstract]
Fair Value	64,000,000		64,000,000		58,000,000
Unrealized Gains	2,000,000		2,000,000		2,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	64,000,000		64,000,000		58,000,000
Money market funds and other
Schedule Of Available For Sale Securities [Abstract]
Fair Value	85,000,000		85,000,000		70,000,000
Unrealized Losses	0		0		0
Unrealized Gains	1,000,000		1,000,000		1,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	85,000,000		85,000,000		87,000,000
Other marketable securities
Other marketable securities	16,000,000		16,000,000		20,000,000
Money market funds and other | PEC
Schedule Of Available For Sale Securities [Abstract]
Fair Value	54,000,000		54,000,000		60,000,000
Unrealized Gains	1,000,000		1,000,000		1,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	51,000,000		51,000,000		47,000,000
Money market funds and other | PEF
Schedule Of Available For Sale Securities [Abstract]
Fair Value	31,000,000		31,000,000		10,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	34,000,000		34,000,000		40,000,000
Commodity derivatives
Derivatives
Derivative assets	8,000,000		8,000,000		5,000,000
Derivatives
Derivative financial instruments	602,000,000		602,000,000		692,000,000
Commodity derivatives | PEC
Derivatives
Derivative assets	2,000,000		2,000,000
Derivatives
Derivative financial instruments	186,000,000		186,000,000		201,000,000
Commodity derivatives | PEF
Derivatives
Derivative assets	6,000,000		6,000,000		5,000,000
Derivatives
Derivative financial instruments	416,000,000		416,000,000		491,000,000
Interest rate derivatives
Derivatives
Derivative financial instruments	22,000,000		22,000,000		93,000,000
Interest rate derivatives | PEC
Derivatives
Derivative financial instruments	11,000,000		11,000,000		47,000,000
Interest rate derivatives | PEF
Derivatives
Derivative financial instruments	11,000,000		11,000,000		8,000,000
CVOs
Derivatives
Derivative financial instruments	3,000,000		3,000,000		14,000,000
Level 1
Nuclear decommissioning trust funds
Decommissioning fund investments	1,274,000,000		1,274,000,000		1,148,000,000
Other marketable securities
Total assets	1,290,000,000		1,290,000,000		1,168,000,000
Level 1 | PEC
Nuclear decommissioning trust funds
Decommissioning fund investments	855,000,000		855,000,000		771,000,000
Other marketable securities
Other marketable securities	2,000,000		2,000,000		6,000,000
Total assets	857,000,000		857,000,000		777,000,000
Level 1 | PEF
Nuclear decommissioning trust funds
Decommissioning fund investments	419,000,000		419,000,000		377,000,000
Other marketable securities
Other marketable securities	1,000,000		1,000,000		1,000,000
Total assets	420,000,000		420,000,000		378,000,000
Level 1 | Common stock equity
Nuclear decommissioning trust funds
Decommissioning fund investments	1,109,000,000		1,109,000,000		1,033,000,000
Level 1 | Common stock equity | PEC
Nuclear decommissioning trust funds
Decommissioning fund investments	727,000,000		727,000,000		673,000,000
Level 1 | Common stock equity | PEF
Nuclear decommissioning trust funds
Decommissioning fund investments	382,000,000		382,000,000		360,000,000
Level 1 | Preferred stock and other equity
Nuclear decommissioning trust funds
Decommissioning fund investments	36,000,000		36,000,000		28,000,000
Level 1 | Preferred stock and other equity | PEC
Nuclear decommissioning trust funds
Decommissioning fund investments	22,000,000		22,000,000		17,000,000
Level 1 | Preferred stock and other equity | PEF
Nuclear decommissioning trust funds
Decommissioning fund investments	14,000,000		14,000,000		11,000,000
Level 1 | U.S. and foreign government debt
Nuclear decommissioning trust funds
Decommissioning fund investments	128,000,000		128,000,000		87,000,000
Level 1 | U.S. and foreign government debt | PEC
Nuclear decommissioning trust funds
Decommissioning fund investments	105,000,000		105,000,000		81,000,000
Level 1 | U.S. and foreign government debt | PEF
Nuclear decommissioning trust funds
Decommissioning fund investments	23,000,000		23,000,000		6,000,000
Level 1 | Money market funds and other
Nuclear decommissioning trust funds
Decommissioning fund investments	1,000,000		1,000,000
Other marketable securities
Other marketable securities	16,000,000		16,000,000		20,000,000
Level 1 | Money market funds and other | PEC
Nuclear decommissioning trust funds
Decommissioning fund investments	1,000,000		1,000,000
Level 2
Additional Fair Value Elements [Abstract]
Long-term Debt, Fair Value	16,400,000,000		16,400,000,000		15,300,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	483,000,000		483,000,000		499,000,000
Other marketable securities
Total assets	491,000,000		491,000,000		504,000,000
Derivatives
Total liabilities	597,000,000		597,000,000		775,000,000
Level 2 | PEC
Additional Fair Value Elements [Abstract]
Long-term Debt, Fair Value	5,800,000,000		5,800,000,000		4,700,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	309,000,000		309,000,000		317,000,000
Other marketable securities
Total assets	311,000,000		311,000,000		317,000,000
Derivatives
Total liabilities	169,000,000		169,000,000		224,000,000
Level 2 | PEF
Additional Fair Value Elements [Abstract]
Long-term Debt, Fair Value	5,500,000,000		5,500,000,000		5,400,000,000
Nuclear decommissioning trust funds
Decommissioning fund investments	174,000,000		174,000,000		182,000,000
Other marketable securities
Total assets	180,000,000		180,000,000		187,000,000
Derivatives
Total liabilities	425,000,000		425,000,000		499,000,000
Level 2 | Preferred stock and other equity
Nuclear decommissioning trust funds
Decommissioning fund investments	11,000,000		11,000,000		1,000,000
Level 2 | Preferred stock and other equity | PEF
Nuclear decommissioning trust funds
Decommissioning fund investments	11,000,000		11,000,000		1,000,000
Level 2 | Corporate debt
Nuclear decommissioning trust funds
Decommissioning fund investments	88,000,000		88,000,000		86,000,000
Level 2 | Corporate debt | PEC
Nuclear decommissioning trust funds
Decommissioning fund investments	73,000,000		73,000,000		69,000,000
Level 2 | Corporate debt | PEF
Nuclear decommissioning trust funds
Decommissioning fund investments	15,000,000		15,000,000		17,000,000
Level 2 | U.S. state and municipal debt
Nuclear decommissioning trust funds
Decommissioning fund investments	135,000,000		135,000,000		128,000,000
Level 2 | U.S. state and municipal debt | PEC
Nuclear decommissioning trust funds
Decommissioning fund investments	62,000,000		62,000,000		56,000,000
Level 2 | U.S. state and municipal debt | PEF
Nuclear decommissioning trust funds
Decommissioning fund investments	73,000,000		73,000,000		72,000,000
Level 2 | U.S. and foreign government debt
Nuclear decommissioning trust funds
Decommissioning fund investments	165,000,000		165,000,000		197,000,000
Level 2 | U.S. and foreign government debt | PEC
Nuclear decommissioning trust funds
Decommissioning fund investments	124,000,000		124,000,000		145,000,000
Level 2 | U.S. and foreign government debt | PEF
Nuclear decommissioning trust funds
Decommissioning fund investments	41,000,000		41,000,000		52,000,000
Level 2 | Money market funds and other
Nuclear decommissioning trust funds
Decommissioning fund investments	84,000,000		84,000,000		87,000,000
Level 2 | Money market funds and other | PEC
Nuclear decommissioning trust funds
Decommissioning fund investments	50,000,000		50,000,000		47,000,000
Level 2 | Money market funds and other | PEF
Nuclear decommissioning trust funds
Decommissioning fund investments	34,000,000		34,000,000		40,000,000
Level 2 | Commodity derivatives
Derivatives
Derivative assets	8,000,000		8,000,000		5,000,000
Derivatives
Derivative financial instruments	572,000,000		572,000,000		668,000,000
Level 2 | Commodity derivatives | PEC
Derivatives
Derivative assets	2,000,000		2,000,000
Derivatives
Derivative financial instruments	158,000,000		158,000,000		177,000,000
Level 2 | Commodity derivatives | PEF
Derivatives
Derivative assets	6,000,000		6,000,000		5,000,000
Derivatives
Derivative financial instruments	414,000,000		414,000,000		491,000,000
Level 2 | Interest rate derivatives
Derivatives
Derivative financial instruments	22,000,000		22,000,000		93,000,000
Level 2 | Interest rate derivatives | PEC
Derivatives
Derivative financial instruments	11,000,000		11,000,000		47,000,000
Level 2 | Interest rate derivatives | PEF
Derivatives
Derivative financial instruments	11,000,000		11,000,000		8,000,000
Level 2 | CVOs
Derivatives
Derivative financial instruments	3,000,000		3,000,000		14,000,000
Level 3
Derivatives
Total liabilities	30,000,000		30,000,000		24,000,000
Fair value hierarchy
Derivatives, net at beginning of period	27,000,000	32,000,000	24,000,000	36,000,000
Deferred as regulatory assets and liabilities, net	3,000,000	5,000,000	6,000,000	1,000,000
Derivatives, net at end of period	30,000,000	37,000,000	30,000,000	37,000,000
Level 3 | PEC
Derivatives
Total liabilities	28,000,000		28,000,000		24,000,000
Fair value hierarchy
Derivatives, net at beginning of period	27,000,000	32,000,000	24,000,000	36,000,000
Deferred as regulatory assets and liabilities, net	1,000,000	5,000,000	4,000,000	1,000,000
Derivatives, net at end of period	28,000,000	37,000,000	28,000,000	37,000,000
Level 3 | PEF
Derivatives
Total liabilities	2,000,000		2,000,000
Level 3 | Commodity derivatives
Derivatives
Derivative financial instruments	30,000,000		30,000,000		24,000,000
Level 3 | Commodity derivatives | PEC
Derivatives
Derivative financial instruments	28,000,000		28,000,000		24,000,000
Level 3 | Commodity derivatives | PEF
Derivatives
Derivative financial instruments	$ 2,000,000		$ 2,000,000
Level 3 | Commodity derivatives | Maximum
Fair Value Inputs Liabilities Quantitative Information [Abstract]
Fair value inputs, price per MMBtu			4.374
Level 3 | Commodity derivatives | Maximum | PEC
Fair Value Inputs Liabilities Quantitative Information [Abstract]
Fair value inputs, price per MMBtu			4.374
Level 3 | Commodity derivatives | Minimum
Fair Value Inputs Liabilities Quantitative Information [Abstract]
Fair value inputs, price per MMBtu			3.956
Level 3 | Commodity derivatives | Minimum | PEC
Fair Value Inputs Liabilities Quantitative Information [Abstract]
Fair value inputs, price per MMBtu			3.956