Employee Benefit Plans (Sensitivity to Changes in Assumed Health Care Cost Trend Rates) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest costs - 1 Percentage Point Increase	$ 11
Effect on total service and interest costs - 1 Percentage Point Decrease	(9)
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	42
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	(36)
Duke Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest costs - 1 Percentage Point Increase	2
Effect on total service and interest costs - 1 Percentage Point Decrease	(1)
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	10
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	(9)
Progress Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest costs - 1 Percentage Point Increase	7
Effect on total service and interest costs - 1 Percentage Point Decrease	(6)
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	20
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	(16)
Duke Energy Progress [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest costs - 1 Percentage Point Increase	4
Effect on total service and interest costs - 1 Percentage Point Decrease	(3)
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	9
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	(7)
Duke Energy Florida [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest costs - 1 Percentage Point Increase	3
Effect on total service and interest costs - 1 Percentage Point Decrease	(2)
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	10
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	(8)
Duke Energy Ohio [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest costs - 1 Percentage Point Increase	1
Effect on total service and interest costs - 1 Percentage Point Decrease	0
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	2
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	(1)
Duke Energy Indiana [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest costs - 1 Percentage Point Increase	1
Effect on total service and interest costs - 1 Percentage Point Decrease	(1)
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	4
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	$ (4)