Stock-Based Compensation Plans (Details 7) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pre-tax stock-based compensation expense	$ 69	$ 60	$ 89
Tax benefit associated with stock-based compensation expense	14	23	11
Stock-based compensation costs capitalized	23	20	29
Restricted Stock and Restricted Stock Units Awards
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pre-tax stock-based compensation expense	31	42	42
Stock Options
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pre-tax stock-based compensation expense	0	0	1
Performance Shares
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pre-tax stock-based compensation expense	5	(10)	5
401(k) Savings Plan
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pre-tax stock-based compensation expense	25	25	37
EDCP
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pre-tax stock-based compensation expense	3	(2)	0
DCPD
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pre-tax stock-based compensation expense	5	5	4
FES
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pre-tax stock-based compensation expense	9	9	13
Tax benefit associated with stock-based compensation expense	2	1	2
Stock-based compensation costs capitalized	1	1	1
FES \| Restricted Stock and Restricted Stock Units Awards
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pre-tax stock-based compensation expense	4	6	6
FES \| Performance Shares
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pre-tax stock-based compensation expense	1	(1)	1
FES \| 401(k) Savings Plan
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Pre-tax stock-based compensation expense	$ 4	$ 4	$ 6

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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