Schedule I - Condensed Financial Information Of Parent Company (Related Party Transactions) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Related Party Transaction [Line Items]
(Payable to) Receivable from Related Party, Total	$ (25)	[1]	$ (3)	[1]
Money Pool Balance with Pepco Holdings (included in cash and cash equivalents)	257		131
Potomac Capital Investment Corporation [Member]
Related Party Transaction [Line Items]
(Payable to) Receivable from Related Party, Total	(37)	[1]
Conectiv, LLC [Member]
Related Party Transaction [Line Items]
(Payable to) Receivable from Related Party, Total	29	[1]
Conectiv Communication, Inc. [Member]
Related Party Transaction [Line Items]
(Payable to) Receivable from Related Party, Total	(4)	[1]	(4)	[1]
Potomac Electric Power Co [Member]
Related Party Transaction [Line Items]
(Payable to) Receivable from Related Party, Total	(15)	[1]
PHI Service Company [Member]
Related Party Transaction [Line Items]
(Payable to) Receivable from Related Party, Total	2	[1]
Other [Member]
Related Party Transaction [Line Items]
(Payable to) Receivable from Related Party, Total			$ 1	[1]

[1] Included in accounts payable due to associated companies.