Severance Expense Table (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]
Severance expense	$ 5	$ 146	$ 30	$ 146
Duke Energy Carolinas [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	0	48	7	48
Progress Energy [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	4	66	17	66
Duke Energy Progress [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	3	42	12	42
Duke Energy Florida [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	1	24	5	24
Duke Energy Ohio [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	0	15	2	15
Duke Energy Indiana [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	$ 0	$ 13	$ 2	$ 13