Consolidated Statement of Changes in Shareholders Equity (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income taxes	$ 340	$ 115	$ 625	$ 805
Exelon Generation Co L L C [Member]
Income taxes	173	(36)	293	371
Atlantic City Electric Company [Member]
Income taxes	23	14	(8)	23
PECO Energy Co [Member]
Income taxes	54	37	121	122
Commonwealth Edison Co [Member]
Income taxes	75	99	244	226
Baltimore Gas and Electric Company [Member]
Income taxes	36	35	109	141
Potomac Electric Power Company [Member]
Income taxes	$ 35	$ 32	$ 34	$ 62