Debt And Credit Facilities (Schedule Of Money Pool Balances) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Duke Energy Carolinas [Member]
Money Pool Receivables	$ 811	$ 923
Money Pool Long Term Debt	300	300
Duke Energy Ohio [Member]
Money Pool Receivables	84	311
Money Pool Notes Payable	2
Duke Energy Indiana [Member]
Money Pool Notes Payable	55	300
Money Pool Long Term Debt	$ 150	$ 150