Commitments And Contingencies (Rate Proceedings) (Details) (USD $)	1 Months Ended	12 Months Ended			0 Months Ended			1 Months Ended			6 Months Ended	0 Months Ended	1 Months Ended	0 Months Ended
	Oct. 31, 2010	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 08, 2011 Delmarva Power & Light Co/De [Member]	May 25, 2011 Delmarva Power & Light Co/De [Member]	May 25, 2011 Delmarva Power & Light Co/De [Member]	Feb. 28, 2011 Delmarva Power & Light Co/De [Member]	Dec. 31, 2010 Delmarva Power & Light Co/De [Member]	Aug. 31, 2010 Delmarva Power & Light Co/De [Member]	Jun. 30, 2011 Delmarva Power & Light Co/De [Member]	Jun. 22, 2011 DCPSC [Member]	Dec. 31, 2009 Maryland [Member]	Aug. 06, 2011 ACE [Member]
Effect of proposed change on gas cost rate	0.10%
Interest foregone associated with amortization	$ 342,000
Requested rate change							12,200,000		17,800,000		10,200,000			58,900,000
Return on equity, percentage						10.00%			10.75%		11.00%	10.00%	10.75%	10.75%
Rate increase implemented								7,700,000		2,500,000		5,800,000
Proposed rate increase					42,000,000									70,500,000
Base rate														17,000,000
Increase in sales-and-use taxes														4,900,000
Adjustments to regulatory asset recovery charge														500,000
Proposed reliability-related capital expenditures				103,000,000
Estimated recoverable capital expenditures		$ 81,000,000	$ 94,000,000	$ 69,000,000