Severance Expense Table (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Restructuring Cost and Reserve [Line Items]
Severance expense	$ 16	[1]
Accelerated Stock Compensation Expense	5
Duke Energy Carolinas [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	5
Progress Energy [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	7
Duke Energy Progress [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	5
Duke Energy Florida [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	2
Duke Energy Ohio [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	1
Duke Energy Indiana [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	$ 2

[1] Includes $5 million of accelerated stock award expense.