Preferred Securities (Details) (USD $) In Millions, except Share data, unless otherwise specified						12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended			12 Months Ended			12 Months Ended			12 Months Ended
	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2013 Preferred Stock [Member]	Dec. 31, 2012 Preferred Stock [Member]	Dec. 31, 2013 Series A Preferred Stock [Member]	Dec. 31, 2012 Series A Preferred Stock [Member]	Dec. 31, 2013 Series B Preferred Stock [Member]	Dec. 31, 2012 Series B Preferred Stock [Member]	Dec. 31, 2013 Series C Preferred Stock [Member]	Dec. 31, 2012 Series C Preferred Stock [Member]	Dec. 31, 2013 Series D Preferred Stock [Member]	Dec. 31, 2012 Series D Preferred Stock [Member]	Dec. 31, 2013 Series 6.97% Preferred Stock [Member]		Dec. 31, 2012 Series 6.97% Preferred Stock [Member]	Dec. 31, 2013 Series 6.7% Preferred Stock [Member]		Dec. 31, 2012 Series 6.7% Preferred Stock [Member]	Dec. 31, 2013 Series 6.99% Preferred Stock [Member]		Dec. 31, 2012 Series 6.99% Preferred Stock [Member]	Dec. 31, 2013 Series 7.125% Preferred Stock [Member]		Dec. 31, 2012 Series 7.125% Preferred Stock [Member]	Dec. 31, 2013 Commonwealth Edison Co [Member] Preferred Stock [Member]	Dec. 31, 2012 Commonwealth Edison Co [Member] Preferred Stock [Member]	Dec. 31, 2013 Commonwealth Edison Co [Member] Cumulative Preferred Stock [Member]	Dec. 31, 2012 Commonwealth Edison Co [Member] Cumulative Preferred Stock [Member]	Dec. 31, 2013 PECO Energy Co [Member]	Dec. 31, 2012 PECO Energy Co [Member]	Dec. 31, 2013 PECO Energy Co [Member] Cumulative Preferred Stock [Member]	Dec. 31, 2012 PECO Energy Co [Member] Cumulative Preferred Stock [Member]	Dec. 31, 2013 Baltimore Gas and Electric Company [Member] Preference Stock [Member]
Preferred Securities Additional Narrative Information [Line Items]
Shares authorized				100,000,000	100,000,000																					850,000	850,000	6,810,451	6,810,451			15,000,000	15,000,000	6,500,000
Preferred Stock, Par or Stated Value Per Share																																		$ 100.000
Class of Stock [Line Items]
Shares outstanding	1,900,000		1,900,000											500,000		500,000	400,000		400,000	600,000		600,000	400,000		400,000
Dollar amount	$ 190	$ 87	$ 190											$ 50		$ 50	$ 40		$ 40	$ 60		$ 60	$ 40		$ 40
Redemption price														$ 100.000	[1]		$ 100.340	[1]		$ 100.700	[1]		$ 100.000	[1]
Dividend Rate Percentage														6.97%			6.70%			6.99%			7.125%
Temporary Equity [Line Items]
Shares outstanding			874,720				300,000		150,000		274,720		150,000
Dollar amount			$ 87				$ 30		$ 15		$ 27		$ 15																	$ 0	$ 87
Redemption price						$ 106.000		$ 102.000		$ 112.500		$ 104.000
Dividend rate per dollar amount						$ 3.80		$ 4.30		$ 4.40		$ 4.68

[1] Redeemable, at the option of BGE, at the indicated dollar amounts per share, plus accrued and unpaid dividends.