Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounts Receivable [Abstract]
Gross accounts receivable pledged as collateral	$ 0
Shareholders' equity
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares outstanding	857,290,484	854,781,389
Treasury Stock, Shares held	35,000,000	35,000,000
PECO Energy Co [Member]
Accounts Receivable [Abstract]
Gross accounts receivable pledged as collateral	$ 0	$ 289
Shareholders' equity
Common stock, shares authorized	500,000,000
Common stock, shares outstanding	170,478,507	170,478,507
Baltimore Gas and Electric Company [Member]
Shareholders' equity
Common stock, shares authorized	175,000,000
Common stock, shares outstanding	1,000	1,000