Regulatory Matters - Retail Rate Matters (Details) (USD $)	9 Months Ended		9 Months Ended				9 Months Ended			3 Months Ended		9 Months Ended		36 Months Ended												9 Months Ended	12 Months Ended	9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 PEC [Member]	Dec. 31, 2011 PEC [Member]	Sep. 30, 2012 PEC [Member] HF Lee Energy Complex [Member]	Sep. 30, 2012 PEC [Member] LV Sutton Plant [Member]	Sep. 30, 2012 PEC [Member] North Carolina Rate Case [Member] North Carolina Rate [Member]	Sep. 30, 2012 PEC [Member] North Carolina Rate Case, net of Energy Efficiency and Demand Side Management [Member] North Carolina Rate [Member]	Sep. 30, 2012 PEF [Member]	Sep. 30, 2012 PEF [Member] Base Rate Settlement Agreement [Member] Regulatory Costs Approved [Member]	Sep. 30, 2011 PEF [Member] Base Rate Settlement Agreement [Member] Regulatory Costs Approved [Member]	Sep. 30, 2012 PEF [Member] Base Rate Settlement Agreement [Member] Regulatory Costs Approved [Member]	Sep. 30, 2011 PEF [Member] Base Rate Settlement Agreement [Member] Regulatory Costs Approved [Member]	Sep. 30, 2012 PEF [Member] Nuclear Cost Recovery [Member] CR3 Outage [Member]		Sep. 30, 2012 PEF [Member] Nuclear Cost Recovery [Member] CR3 Outage [Member] Planned Scenario [Member] M	Sep. 30, 2012 PEF [Member] Nuclear Cost Recovery [Member] CR3 Outage [Member] Previous Bid Scenario [Member] M	Sep. 30, 2012 PEF [Member] Nuclear Cost Recovery [Member] CR3 Outage [Member] Expanded Scope Of Work [Member] M	Sep. 30, 2012 PEF [Member] Nuclear Cost Recovery [Member] CR3 Outage [Member] Worst Case Scenario [Member] M	Sep. 30, 2012 PEF [Member] Nuclear Cost Recovery [Member] CR3 Outage [Member] Minimum [Member]	Sep. 30, 2012 PEF [Member] Nuclear Cost Recovery [Member] CR3 Outage [Member] Maximum [Member]	Sep. 30, 2012 PEF [Member] Nuclear Cost Recovery [Member] Levy Units 1 And 2 [Member]	Sep. 30, 2012 PEF [Member] Nuclear Cost Recovery [Member] Levy Units 1 And 2 [Member] Minimum [Member]	Sep. 30, 2012 PEF [Member] Nuclear Cost Recovery [Member] Levy Units 1 And 2 [Member] Maximum [Member]	Sep. 30, 2012 PEF [Member] Environmental Cost Recovery Clause [Member] Anclote Units 1 And 2 [Member]	Sep. 30, 2012 PEF [Member] 2012 Settlement Agreement [Member] Regulatory Costs Approved [Member] Base Rates Customer Refund And Other [Member]	Dec. 31, 2011 PEF [Member] 2012 Settlement Agreement [Member] Regulatory Costs Approved [Member] Base Rates Customer Refund And Other [Member]	Sep. 30, 2012 PEF [Member] 2012 Settlement Agreement [Member] Regulatory Costs Approved [Member] Crystal River Three [Member]	Sep. 30, 2012 PEF [Member] 2012 Settlement Agreement [Member] Regulatory Costs Approved [Member] Proposed Levy Plant [Member]
Public utilities, disclosure of date of regulatory filing							October 12, 2012
Requested Rate Increase Amount to State Commission							$ 387,000,000	$ 359,000,000
Percent increase in rates							12.00%	11.00%
Increase in rates total																										150,000,000
Return on equity							11.25%
Capital Structure, equity percentage							55.00%
Capital Structure, long-term debt percentage							45.00%
Estimated capital cost of new utility plant, including AFUDC					750,000,000	600,000,000																	19,000,000,000	24,000,000,000	79,000,000
Repair costs, range of possible costs																				900,000,000	1,300,000,000
Independent review repair costs																1,490,000,000	1,550,000,000	2,440,000,000	3,430,000,000
Independent review, estimated time to return to service																35	31	60	96
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														573,000,000
NEIL insurance recoveries related to replacement power costs														(162,000,000)
Amount included in deferred fuel regulatory asset, replacement power costs														411,000,000	[1]
Amount of repair costs incurred														324,000,000
NEIL insurance recoveries related to repair costs														(143,000,000)
Repair costs to be recovered														181,000,000	[1]
Public utilities, cost of removal reserve, reduction taken subject to regulatory order										60,000,000	71,000,000	118,000,000	205,000,000
Public utilities, cost of removal reserve, amount subject to regulatory order										169,000,000		169,000,000
Public utilities, rate of returns, authorized																										11.50%
Public utilities, rate of returns below threshold, subject to regulatory order																										9.50%
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
Replacement power refund																												100,000,000
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
Amount of Reduction to Carrying Amount of Regulatory Liabilities																										47,000,000
Plant in-service date, projected					December 2012	December 2013																2024
NEIL reimbursements withheld														70,000,000
Allocated wholesale costs																												130,000,000	60,000,000
Generation facilities to be retired, net	164,000,000	163,000,000	164,000,000	163,000,000
Net carrying value of retired generating facilities			57,000,000
Asset Retirement Obligation Revision Of Estimate	$ 813,000,000		$ 684,000,000						$ 129,000,000

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