Regulatory Matters - Retail Rate Matters (Details) (USD $)	3 Months Ended		12 Months Ended		12 Months Ended										12 Months Ended									27 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 PEC	Dec. 31, 2010 PEC	Dec. 31, 2011 PEC Regulatory Costs Approved North Carolina Rate	Dec. 31, 2011 PEC Regulatory Costs Approved South Carolina Rate	Dec. 31, 2011 PEC Fuel Cost Recovery Regulatory Costs Approved North Carolina Rate	Dec. 31, 2011 PEC Fuel Cost Recovery Regulatory Costs Approved South Carolina Rate	Dec. 31, 2011 PEC Demand Side Management and Energy Efficiency Cost Recovery Regulatory Costs Approved North Carolina Rate	Dec. 31, 2011 PEC Demand Side Management and Energy Efficiency Cost Recovery Regulatory Costs Approved South Carolina Rate	Dec. 31, 2011 PEC Base Rates Regulatory Costs Approved	Dec. 31, 2011 PEC NC REPS Regulatory Costs Approved North Carolina Rate	Dec. 31, 2011 PEF	Dec. 31, 2010 PEF	Dec. 31, 2009 PEF Regulatory Costs Approved	Dec. 31, 2011 PEF Fuel Cost Recovery Regulatory Costs Approved	Dec. 31, 2011 PEF Fuel Cost Recovery Regulatory Costs Approved Capacity Cost Recovery Clause	Dec. 31, 2011 PEF Fuel Cost Recovery Regulatory Costs Approved Projected Recovery Of Fuel Costs	Dec. 31, 2011 PEF Base Rate Settlement Agreement Regulatory Costs Approved	Dec. 31, 2011 PEF Nuclear Cost Recovery Regulatory Costs Approved	Dec. 31, 2009 PEF Nuclear Cost Recovery Regulatory Costs Approved	Dec. 31, 2011 PEF Nuclear Cost Recovery Levy Units 1 and 2, Generating Facilities	Dec. 31, 2011 PEF Nuclear Cost Recovery Levy Units 1 And 2, Transmission Facilities	Dec. 31, 2011 PEF Nuclear Cost Recovery CR3 Outage weeks	Dec. 31, 2011 PEF Allowance For Funds Used During Construction Regulatory Costs Approved	Dec. 31, 2011 PEF Environmental Cost Recovery Clause Regulatory Costs Approved	Dec. 31, 2011 PEF Energy Conservation Cost Recovery Clause Regulatory Costs Approved	Dec. 31, 2011 PEF 2012 Settlement Agreement Regulatory Costs Approved	Dec. 31, 2011 PEF 2012 Settlement Agreement Regulatory Costs Approved Base Rates Customer Refund And Other	Dec. 31, 2011 PEF 2012 Settlement Agreement Regulatory Costs Approved Crystal River Three	Dec. 31, 2011 PEF 2012 Settlement Agreement Regulatory Costs Approved Proposed Levy Member
Increase in rates total							$ 85,000,000	$ 22,000,000	$ 24,000,000	$ 4,000,000		$ 9,000,000				$ 162,000,000					$ 446,000,000					$ 24,000,000			$ 150,000,000
Decrease in rates total																				78,000,000
Public utilities, disclosure of effective date							December 1, 2011	July 1, 2011	December 1, 2011	July 1, 2011		December 1, 2011				January 1, 2012			June 1, 2010	January 2012	January 2010				January 11, 2010	January 1, 2012	January 1, 2012		January 2013		January 2013
Increase in rates per 1,000 kWH							2.75	3.45	1.08	1.25		0.02				3.32		3.99								0.54		4.93			3.45
Decrease in rates per 1,000 kWH																	0.67			2.67							0.11
Percent increase in rates					3.70%	4.70%										2.78%										0.50%	0.10%	4.00%
Net carrying value of facilities intended to retire			163,000,000
Disallowed Costs							24,000,000
Repair costs, range of possible costs, minimum																								900,000,000
Repair costs, range of possible costs, maximum																								1,300,000,000
Property, return to service date																								2014
Nuclear operating license, expiration period			2030 and 2046										December 2016
Replacement power insurance coverage weeks, primary																								52
Replacement power insurance coverage amount per week, primary																								4,500,000
Replacement power insurance coverage weeks, additional																								71
Replacement power insurance coverage expiration																								August 2012
Replacement power insurance coverage amount per week, additional																								3,600,000
Replacement power insurance coverage amount, total																								490,000,000
NEIL coverage per company at each nuclear plant																								2,250,000,000
Insurance deductible per claim																								10,000,000
Replacement power costs incurred																								478,000,000
NEIL insurance recoveries related to replacement power costs																								(162,000,000)
Estimated insurance recoveries, replacement power																								(55,000,000)
Amount included in deferred fuel regulatory asset, replacement power costs																								261,000,000
Amount of repair costs incurred																								258,000,000
NEIL insurance recoveries related to repair costs																								(136,000,000)
Estimated insurance recoveries, repair costs																								(3,000,000)
Repair costs to be recovered																								119,000,000
Public utilities, cost of removal reserve, reduction for period subject to regulatory order 2010																			150,000,000
Public utilities, cost of removal reserve, reduction for period subject to regulatory order 2011																			250,000,000
Public utilities, cost of removal reserve, reduction taken subject to regulatory order																			250,000,000
Public utilities, cost of removal reserve, amount subject to regulatory order																			246,000,000
Public utilities, rate of returns, authorized											12.75%								11.50%										9.50%
Public utilities, rate of returns below threshold, subject to regulatory order																			9.50%										11.50%
Public utilities, minimum cost of removal reduction threshold, subject to regulatory order																			150,000,000
Public utilities, maximum residential recovery, storm costs, subject to refund per regulatory order																			4.00
Amount for recovery of prior year deferral in future periods																				60,000,000
Capacity revenue reclassified pursuant to state nuclear cost recovery rule																					198,000,000
Accelerated amortization of preconstruction costs reclassified pursuant to state nuclear cost recovery rule																					76,000,000
Regulatory asset related to deferred recovery pursuant to state nuclear cost recovery rule																					274,000,000
Construction project cost estimates																						14,000,000,000	3,000,000,000
Allowance for funds used during construction rate historic																									8.80%
Allowance for funds used during construction rate current																									7.40%				7.40%
Storm reserve, approved																			136,000,000
Pension expense deferral, requested															53,000,000
Pension expense deferral, recorded															34,000,000
Annual permitted pension deferral amortization															PEF will amortize the deferred pension regulatory asset to the extent that annual pension expense is less than the $27 million allowance provided for in the base rates established in the 2010 base rate proceeding
Pension expense deferral, base rate recovery period															no earlier than 2015
Total long-term regulatory assets	3,025,000,000	2,374,000,000	1,310,000,000	987,000,000					78,000,000	14,000,000			1,602,000,000	1,387,000,000						117,000,000
Total current regulatory liabilities	48,000,000	59,000,000						2,000,000												15,000,000						7,000,000	19,000,000
Total long-term regulatory liabilities	2,700,000,000	2,635,000,000	1,543,000,000	1,461,000,000									1,071,000,000	1,084,000,000					132,000,000										288,000,000
Regulatory assets	275,000,000	176,000,000					31,000,000						244,000,000	105,000,000		244,000,000
Net carrying value of facilities retired			15,000,000
Repair Costs Reclassified From Receivables To CWIP																								68,000,000
Replacement Power Costs Reclassified From Receivables To Deferred Fuel																								154,000,000
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																												$ 288,000,000