Notes Receivable (Schedule Of Allowance For Loan Losses) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses, at beginning of period	$ 5	$ 5
Charge-offs	(5)	(5)
Recoveries	1	1
Provision for loan losses	4	4
Allowance for loan losses, at end of period	5	5
EnerBank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Delinquent loans	4	3
Loans modified as troubled debt restructurings	$ 1	$ 1