Employee Benefit Plans (Information For Plans with Accumulated Benefit Obligation in Excess of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Qualified Pension Plans [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	$ 1,299	$ 1,216
Accumulated benefit obligation	1,239	1,158
Fair value of plan assets	(1,182)	(1,151)
Qualified Pension Plans [Member] | Progress Energy [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	665	611
Accumulated benefit obligation	633	575
Fair value of plan assets	(604)	(574)
Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	665	611
Accumulated benefit obligation	633	575
Fair value of plan assets	(604)	(574)
Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	311	307
Accumulated benefit obligation	299	298
Fair value of plan assets	(286)	(289)
Non-Qualified Pension Plans [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	332	341
Accumulated benefit obligation	332	336
Non-Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	14	16
Accumulated benefit obligation	14	16
Non-Qualified Pension Plans [Member] | Progress Energy [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	114	112
Accumulated benefit obligation	114	112
Non-Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	33	33
Accumulated benefit obligation	33	33
Non-Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	46	46
Accumulated benefit obligation	46	46
Non-Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	4	4
Accumulated benefit obligation	4	4
Non-Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	3	5
Accumulated benefit obligation	$ 3	$ 5