Consolidated Statements of Equity (USD $) In Millions, except Share data	Total USD ($)	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, 2010	$ 4,198	$ 2	$ 3,275	$ 1,027	$ (106)	$ 1,428		$ 705	$ 723	$ 841		$ 347	$ 494	$ 703	$ 26	$ 516	$ 161
Common Stock, Shares, Outstanding, Beginning Balance at Dec. 31, 2010		225,082,252					100				1,000				8,546,017
Net (loss) income	257			257		99			99	71			71	39			39
Other comprehensive income	43				43
Capital contribution from Parent														60		60
Dividends on common stock	(244)			(244)		(25)			(25)	(60)			(60)
Original issue shares, net	17		17
Original issue shares, net, shares		854,124
Shareholder DRP original shares	30		30
Shareholder DRP original shares, shares	2,000,000	1,563,814
Net activity related to stock-based awards	3		3
Balance at Dec. 31, 2011	4,304	2	3,325	1,040	(63)	1,502			797	852			505	802	26	576	200
Common Stock, Shares, Outstanding, Ending Balance at Dec. 31, 2011		227,500,190					100				1,000				8,546,017
Net (loss) income	68					24				21				2
Balance at Mar. 31, 2012
Balance at Dec. 31, 2011	4,304	2	3,325	1,040	(63)	1,502		705	797	852		347	505	802	26		200
Common Stock, Shares, Outstanding, Beginning Balance at Dec. 31, 2011		227,500,190					100				1,000				8,546,017
Net (loss) income	285			285		126			126	73			73	35			35
Other comprehensive income	15				15
Capital contribution from Parent						50		50		60		60
Dividends on common stock	(248)			(248)		(35)			(35)					(35)			(35)
Original issue shares, net	19		19
Original issue shares, net, shares		854,060
Shareholder DRP original shares	32		32
Shareholder DRP original shares, shares	2,000,000	1,661,177
Net activity related to stock-based awards	7		7
Balance at Dec. 31, 2012	4,414	2	3,383	1,077	(48)	1,643		755	888	985		407	578	802	26		200
Common Stock, Shares, Outstanding, Ending Balance at Dec. 31, 2012	230,015,427	230,015,427				100	100			1,000	1,000			8,546,017	8,546,017
Balance at Sep. 30, 2012
Net (loss) income	43					25				17				20
Balance at Dec. 31, 2012	4,414					1,643				985				802	26
Common Stock, Shares, Outstanding, Ending Balance at Dec. 31, 2012	230,015,427					100	100			1,000	1,000			8,546,017	8,546,017
Net (loss) income	(430)					23				26				9
Balance at Mar. 31, 2013
Balance at Dec. 31, 2012	4,414	2	3,383	1,077	(48)	1,643		755	888	985			578	802	26	576	200
Common Stock, Shares, Outstanding, Beginning Balance at Dec. 31, 2012	230,015,427	230,015,427				100	100			1,000	1,000			8,546,017	8,546,017
Net (loss) income	(212)			(212)		150			150	89			89	50			50
Other comprehensive income	14				14
Capital contribution from Parent						175		175						75		75
Dividends on common stock	(270)			(270)		(46)			(46)	(30)			(30)	(60)			(60)
Original issue shares, net	332	1	331
Original issue shares, net, shares		18,734,128
Shareholder DRP original shares	30		30
Shareholder DRP original shares, shares	2,000,000	1,575,343
Net activity related to stock-based awards	7		7
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, Ending Balance at Dec. 31, 2013	250,324,898	250,324,898				100	100			1,000	1,000			8,546,017	8,546,017
Balance at Sep. 30, 2013
Net (loss) income	58					24				28				9
Balance at Dec. 31, 2013	$ 4,315					$ 1,922				$ 1,044		$ 407		$ 867	$ 26
Common Stock, Shares, Outstanding, Ending Balance at Dec. 31, 2013	250,324,898					100	100			1,000	1,000			8,546,017	8,546,017