Earnings Per Share and Equity - Narrative (Details) (USD $) In Millions, except Share data, unless otherwise specified			3 Months Ended	6 Months Ended	3 Months Ended		9 Months Ended	3 Months Ended	6 Months Ended	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Equity units issued [Member]	Sep. 30, 2014 Equity units issued [Member]	Sep. 30, 2014 Employee Stock Option [Member]	Sep. 30, 2013 Employee Stock Option [Member]	Sep. 30, 2014 Employee Stock Option [Member]	Sep. 30, 2014 Equity Forward Units [Member]	Sep. 30, 2014 Equity Forward Units [Member]	Sep. 30, 2014 PECO Energy Co [Member]
Statement Of Equity Line Item [Line Items]
Stock options not included in the calculation of diluted common shares outstanding			2,000,000	1,000,000	16,000,000	20,000,000	16,000,000	2,000,000	1,000,000
Treasury Stock, Shares held	35,000,000	35,000,000
Treasury Stock, Value	$ 2,327	$ 2,327
Preferred Stock Redemption Premium										6
PECO Cumulative Preferred Securities Redeemable										$ 87