Severance Expense Table (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012		Sep. 30, 2012
Severance expense	$ 146	[1]	$ 146	[1]
COBRA and Healthcare Expense Reimbursement	16		16
Accelerated Stock Compensation Expense	14		14
Duke Energy Carolinas [Member]
Severance expense	48		48
Duke Energy Ohio [Member]
Severance expense	15		15
Duke Energy Indiana [Member]
Severance expense	$ 13		$ 13

[1] Includes $16 million of COBRA and healthcare reimbursement expenses and $14 million of accelerated stock award expense.