Consolidated Statements of Equity (USD $) In Millions, except Share data, unless otherwise specified	Total USD ($)	Common Stock [Member] USD ($)	Premium on Stock [Member] USD ($)	Retained Earnings [Member] USD ($)	Accumulated Other Comprehensive (Loss) Income [Member] USD ($)	Potomac Electric Power Co [Member] USD ($)	Potomac Electric Power Co [Member] Common Stock [Member]	Potomac Electric Power Co [Member] Premium on Stock [Member] USD ($)	Potomac Electric Power Co [Member] Retained Earnings [Member] USD ($)	Delmarva Power & Light Co/De [Member] USD ($)	Delmarva Power & Light Co/De [Member] Common Stock [Member]	Delmarva Power & Light Co/De [Member] Premium on Stock [Member] USD ($)	Delmarva Power & Light Co/De [Member] Retained Earnings [Member] USD ($)	Atlantic City Electric Co [Member] USD ($)	Atlantic City Electric Co [Member] Common Stock [Member] USD ($)	Atlantic City Electric Co [Member] Premium on Stock [Member] USD ($)	Atlantic City Electric Co [Member] Retained Earnings [Member] USD ($)
BALANCE at Dec. 31, 2013	$ 4,315	$ 3	$ 3,751	$ 595	$ (34)	$ 1,922		$ 930	$ 992	$ 1,044		$ 407	$ 637	$ 867	$ 26	$ 651	$ 190
Common Stock, Shares, Outstanding, Beginning Balance at Dec. 31, 2013	250,324,898	250,324,898				100	100			1,000	1,000			8,546,017	8,546,017
Net Income	75			75		32			32	37			37	10			10
Other comprehensive income	1				1
Capital contribution from Parent						80		80
Dividends on common stock	(68)			(68)						(20)			(20)	(26)			(26)
Issuance of common stock:
Original issue shares, net	3		3
Original issue shares, net, shares		284,022
Shareholder DRP original issue shares	8		8
Shareholder DRP original issue shares, shares		374,003
Net activity related to stock-based awards	2		2
BALANCE at Mar. 31, 2014	$ 4,336	$ 3	$ 3,764	$ 602	$ (33)	$ 2,034		$ 1,010	$ 1,024	$ 1,061		$ 407	$ 654	$ 851	$ 26	$ 651	$ 174
Common Stock, Shares, Outstanding, Ending Balance at Mar. 31, 2014	250,982,923	250,982,923				100	100			1,000	1,000			8,546,017	8,546,017