Regulatory Matters (Narrative) (Details) (USD $)	1 Months Ended									16 Months Ended	1 Months Ended
	May 31, 2011	Mar. 31, 2011	Jul. 31, 2011 Maximum [Member]	Jul. 31, 2011 Minimum [Member]	Jun. 30, 2011 DTI [Member]	Jun. 30, 2011 Rider R [Member] Virginia Power [Member]	Jun. 30, 2011 Rider S [Member] Virginia Power [Member]	Jun. 30, 2011 Rider R and S [Member] Virginia Power [Member]	May 31, 2011 Rider T [Member] Virginia Power [Member]	Dec. 31, 2012 Rider T [Member] Virginia Power [Member]	Jun. 30, 2011 Rider B [Member] Virginia Power [Member]	May 31, 2011 Rider W [Member] Virginia Power [Member]	Jun. 30, 2011 Virginia Power [Member]	May 31, 2011 Virginia Power [Member]
Annual fuel factor increase rate, projected balance of prior year under-recovered fuel expenses														$ 434,000,000
Annual fuel factor increase													319,000,000
Proposed revenue requirement under Riders						81,000,000	249,000,000		481,000,000		7,000,000	39,000,000
Proposed return on equity utilized in Rider filings								12.50%			12.50%	12.50%
Increase in revenue under revenue requirements for Riders						3,000,000	50,000,000		144,000,000
Revenue requirement under Riders										466,000,000
Expected project cost excluding financing costs												1,100,000,000
Expected cost to convert power stations excluding financing costs											166,000,000
Approved project cost					634,000,000
Proposed annual cost of service	150,000,000
Requested accelerated PIR spending		200,000,000
Stipulation of increase in annual PIR capital investment from the current level			$ 160,000,000	$ 120,000,000