Severance Expense Table (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2010
Restructuring Cost and Reserve [Line Items]
Severance expense	$ 201	[1]	$ 172
COBRA and Healthcare Expense Reimbursement	19
Accelerated Stock Compensation Expense	14
Duke Energy Carolinas [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	63		99
Progress Energy [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	82
Progress Energy Carolinas [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	55
Progress Energy Florida [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	27
Duke Energy Ohio [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	21		24
Duke Energy Indiana [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	$ 18		$ 33

[1] Includes $14 million of accelerated stock award expense and $19 million of COBRA and healthcare reimbursement expenses for 2012.