Employee Benefit Plans (Contributions to Defined Benefit Pension Plans) (Details) (Qualified Pension Plans [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 250	$ 304	$ 200
Anticipated contribution	143
Duke Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions			33
Anticipated contribution	42
Progress Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	250	346	334
Anticipated contribution	51
Duke Energy Progress [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	63	141	217
Anticipated contribution	21
Duke Energy Florida [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	133	128	112
Anticipated contribution	21
Duke Energy Ohio [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions			48
Anticipated contribution	4
Duke Energy Indiana [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions			52
Anticipated contribution	$ 9