Commitments And Contingent Liabilities (Nuclear Insurance Coverages And Assessments) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011
Commitments And Contingent Liabilities [Abstract]
Nuclear insurance aggregate limit	$ 3,200,000,000
Limit of liability per Price Anderson Act	12,600,000,000
Ownership interest per reactor per incident	118,000,000
Ownership interest, payable per reactor, per incident, per year	18,000,000
Maximum aggregate assessment per incident	370,000,000
Maximum aggregate annual assessment	$ 55,000,000