Schedule I - Condensed Financial Information of Parent Company - Related Party Transactions (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
(Payable to) Receivable from Related Party, Total	$ (1)	$ (2)
Money Pool Balance with Pepco Holdings (included in cash and cash equivalents)		262
Conectiv Communication, Inc. [Member]
(Payable to) Receivable from Related Party, Total	(4)	(4)
PHI Service Company [Member]
(Payable to) Receivable from Related Party, Total	3	1
Other [Member]
(Payable to) Receivable from Related Party, Total		1
Potomac Capital Investment Corporation (PCI) [Member]
Potomac Capital Investment Corporation	$ (491)