Commitments and Contingencies (Workforce Reduction Program) (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2010	Dec. 31, 2010
Loss Contingencies [Line Items]
Percent of workforce reduction	9.00%
Before tax severance costs	$ 338
After-tax severance costs	206
Workforce reduction expenditure		109
Virginia Electric and Power Company
Loss Contingencies [Line Items]
Percent of workforce reduction	11.00%
Before tax severance costs	202
After-tax severance costs	123
Workforce reduction expenditure		$ 104

The charge against earnings in the period for known and estimated costs of termination benefits provided to current employees that are involuntarily terminated under a benefit arrangement associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, excluding costs or losses pertaining to an entity newly acquired in a business combination or a discontinued operation as defined by generally accepted accounting principles and costs associated with one-time termination benefits.

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