Regulatory Matters - Retail Rate Matters (Details) (USD $)	3 Months Ended			30 Months Ended				3 Months Ended		12 Months Ended	3 Months Ended
	Mar. 31, 2012 PEC Demand Side Management and Energy Efficiency Cost Recovery Regulatory Costs Not Yet Approved South Carolina Rate	Mar. 31, 2012 PEF Base Rate Settlement Agreement Regulatory Costs Approved	Mar. 31, 2012 PEF Nuclear Cost Recovery Regulatory Costs Not Yet Approved	Mar. 31, 2012 PEF Nuclear Cost Recovery CR3 Outage weeks		Mar. 31, 2012 PEF Nuclear Cost Recovery Levy Units 1 And 2	Mar. 31, 2012 PEF Environmental Cost Recovery Clause Regulatory Costs Not Yet Approved	Mar. 31, 2012 PEF 2012 Settlement Agreement Regulatory Costs Approved	Mar. 31, 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	Mar. 31, 2012 PEF 2012 Settlement Agreement Regulatory Costs Approved Crystal River Three	Mar. 31, 2012 PEF 2012 Settlement Agreement Regulatory Costs Approved Proposed Levy Member
Public utilities, disclosure of date of regulatory filing	March 1, 2012		April 30, 2012
Increase in rates total	$ 5,000,000								$ 150,000,000
Public utilities, disclosure of effective date									January 2013			January 2013
Increase in rates per 1,000 kWH	1.37		2.23					4.93				3.45
Percent increase in rates								4.00%
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
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 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				506,000,000
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				289,000,000	[1]
Amount of repair costs incurred				279,000,000
NEIL insurance recoveries related to repair costs				(143,000,000)
Estimated insurance recoveries, repair costs				0
Repair costs to be recovered				136,000,000	[1]
Public utilities, cost of removal reserve, reduction taken subject to regulatory order		58,000,000
Public utilities, cost of removal reserve, amount subject to regulatory order		216,000,000
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							79,000,000
Amount of Reduction to Carrying Amount of Regulatory Liabilities									47,000,000
Construction project cost estimates range, high end						24,000,000,000
Construction project cost estimates range, low end						$ 19,000,000,000
Plant in-service date, projected						2024

[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.