Consolidated Statement of Changes in Shareholders Equity (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income taxes	$ 102	$ 327	$ 285	$ 690
Exelon Generation Co L L C [Member]
Income taxes	(31)	181	120	407
Atlantic City Electric Company [Member]
Income taxes	2	4	(31)	9
PECO Energy Co [Member]
Income taxes	23	27	67	85
Commonwealth Edison Co [Member]
Income taxes	91	68	168	127
Baltimore Gas and Electric Company [Member]
Income taxes	6	32	73	105
Potomac Electric Power Company [Member]
Income taxes	$ 23	$ 18	$ (1)	$ 30