Regulatory Matters - Retail Rate Matters (Details) (USD $)		6 Months Ended						3 Months Ended	6 Months Ended					32 Months Ended								6 Months Ended		12 Months Ended	6 Months Ended
	Jun. 30, 2012 PEC	Jun. 30, 2012 PEC Regulatory Costs Not Yet Approved North Carolina Rate	Jun. 30, 2012 PEC Regulatory Costs Approved South Carolina Rate	Jun. 30, 2012 PEC Fuel Cost Recovery Regulatory Costs Not Yet Approved North Carolina Rate	Jun. 30, 2012 PEC Fuel Cost Recovery Regulatory Costs Approved South Carolina Rate	Jun. 30, 2012 PEC Demand Side Management and Energy Efficiency Cost Recovery Regulatory Costs Not Yet Approved North Carolina Rate	Jun. 30, 2012 PEC Demand Side Management and Energy Efficiency Cost Recovery Regulatory Costs Approved South Carolina Rate	Jun. 30, 2011 PEF Base Rate Settlement Agreement Regulatory Costs Approved	Jun. 30, 2012 PEF Base Rate Settlement Agreement Regulatory Costs Approved	Jun. 30, 2011 PEF Base Rate Settlement Agreement Regulatory Costs Approved	Jun. 30, 2012 PEF Nuclear Cost Recovery Regulatory Costs Not Yet Approved	Jun. 30, 2012 PEF Nuclear Cost Recovery CR3 Outage weeks		Jun. 30, 2012 PEF Nuclear Cost Recovery CR3 Outage weeks		Jun. 30, 2012 PEF Nuclear Cost Recovery CR3 Outage Minimum	Jun. 30, 2012 PEF Nuclear Cost Recovery CR3 Outage Maximum	Jun. 30, 2012 PEF Nuclear Cost Recovery Levy Units 1 And 2	Jun. 30, 2012 PEF Nuclear Cost Recovery Levy Units 1 And 2 Minimum	Jun. 30, 2012 PEF Nuclear Cost Recovery Levy Units 1 And 2 Maximum	Jun. 30, 2012 PEF Environmental Cost Recovery Clause Regulatory Costs Not Yet Approved	Jun. 30, 2012 PEF 2012 Settlement Agreement Regulatory Costs Approved	Jun. 30, 2012 PEF 2012 Settlement Agreement Regulatory Costs Approved Base Rates Customer Refund And Other	Dec. 31, 2011 PEF 2012 Settlement Agreement Regulatory Costs Approved Base Rates Customer Refund And Other	Jun. 30, 2012 PEF 2012 Settlement Agreement Regulatory Costs Approved Crystal River Three	Jun. 30, 2012 PEF 2012 Settlement Agreement Regulatory Costs Approved Proposed Levy Member
Public utilities, disclosure of date of regulatory filing				June 4, 2012		June 4, 2012					April 30, 2012
Increase in rates total						$ 16,000,000	$ 5,000,000																$ 150,000,000
Decrease in rates total				40,000,000	23,000,000
Public utilities, disclosure of effective date				December 1, 2012	July 1, 2012	December 1, 2012	July 1, 2012				January 2013												January 2013			January 2013
Increase in rates per 1,000 kWH						0.70	1.37				2.23											4.93				3.45
Decrease in rates per 1,000 kWH				1.31	3.65
Percent increase in rates																						4.00%
Percent decrease in rates		0.60%	2.30%
Net carrying value of facilities intended to retire	212,000,000
Repair costs, range of possible costs																900,000,000	1,300,000,000
Replacement power insurance coverage weeks, primary												52		52
Replacement power insurance coverage amount per week, primary												4,500,000		4,500,000
Replacement power insurance coverage weeks, additional												71		71
Replacement power insurance coverage expiration												August 2012		August 2012
Replacement power insurance coverage amount per week, additional												3,600,000		3,600,000
Replacement power insurance coverage amount, total												490,000,000		490,000,000
NEIL coverage per company at each nuclear plant												2,250,000,000		2,250,000,000
Insurance deductible per claim												10,000,000		10,000,000
Replacement power costs incurred														534,000,000
NEIL insurance recoveries related to replacement power costs														(162,000,000)
Amount included in deferred fuel regulatory asset, replacement power costs												372,000,000	[1]	372,000,000	[1]
Amount of repair costs incurred												305,000,000		305,000,000
NEIL insurance recoveries related to repair costs														(143,000,000)
Repair costs to be recovered												162,000,000	[1]	162,000,000	[1]
Public utilities, cost of removal reserve, reduction taken subject to regulatory order								54,000,000	58,000,000	134,000,000
Public utilities, cost of removal reserve, amount subject to regulatory order									232,000,000
Public utilities, rate of returns, authorized																							11.50%
Public utilities, rate of returns below threshold, subject to regulatory order																							9.50%
Amount for recovery of prior year deferral in future periods											88,000,000
Allowance for funds used during construction rate current																							7.40%
Annual cost recovery											152,000,000
Public utilities, disclosure of end date																						December 2016
2015 pro rata replacement power refund																									40,000,000
2016 pro rata replacement power refund																									60,000,000
Repair overrun maximum																									400,000,000
Authorized ROE on retired plant																									70.00%
Public utilities, rate of returns below threshold, subject to regulatory order, escalated																							9.70%
Public utilities, rate of returns, authorized, escalated																							11.70%
2013 Customer refunds																							129,000,000
2014 Customer refunds																							129,000,000
2014 Residential and small commercial customer refunds																							10,000,000
2015 Residential and small commercial customer refunds																							10,000,000
2016 Residential and small commercial customer refunds																							10,000,000
Refund to customers recorded as a reduction to revenue																								288,000,000
Property, Plant and Equipment, Additions, Proposed																			19,000,000,000	24,000,000,000	79,000,000
Amount of Reduction to Carrying Amount of Regulatory Liabilities																							47,000,000
Plant in-service date, projected																		2024
Deferred costs recognized												18,000,000
NEIL reimbursements withheld												70,000,000		70,000,000
Allocated wholesale costs																									$ 130,000,000	$ 60,000,000

[1] See "2012 Settlement Agreement" below for discussion of PEF's ability to recover prudently incurred fuel and purchased power costs and CR3 repair costs.