Consolidated Balance Sheets (Unaudited) (Parenthetical)	Dec. 31, 2015 $ / shares shares
Common stock, par value | $ / shares	$ 0
Common stock, shares authorized	2,000,000,000
Common Stock, Shares, Outstanding	919,924,742
Treasury Stock, Shares held	35,000,000
Commonwealth Edison Co [Member]
Common Stock, Shares, Outstanding	127,016,973
PECO Energy Co [Member]
Common Stock, Shares, Outstanding	170,478,507
Baltimore Gas and Electric Company [Member]
Common Stock, Shares, Outstanding	1,000
Pepco Holdings LLC [Member] | Predecessor [Member]
Common stock, shares authorized	400,000,000.00
Common Stock, Shares, Outstanding	254,289,261.00
Preferred Stock, Par or Stated Value Per Share | $ / shares	$ 0.01
Common Stock, Par or Stated Value Per Share | $ / shares	$ 0.01
Potomac Electric Power Company [Member]
Common Stock, Shares, Outstanding	100
Delmarva Power and Light Company [Member]
Common Stock, Shares, Outstanding	1,000
Atlantic City Electric Company [Member]
Common Stock, Shares, Outstanding	8,546,017