Employee Benefit Plans (Employee Savings Plans)(Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee Savings Plans [Abstract]
Pretax employer matching contributions	$ 134	$ 107	$ 86
Duke Energy Carolinas [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	45	37	37
Progress Energy [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	45	45	44
Duke Energy Progress [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	25	24	23
Duke Energy Florida [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	14	15	14
Duke Energy Ohio [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	3	4	4
Duke Energy Indiana [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	$ 7	$ 6	$ 8