Employee Benefit Plans (Information For Plans with Accumulated Benefit Obligation in Excess of Plan Assets) (Details) - Pension Plan - Qualified Plan - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation		$ 679
Accumulated benefit obligation		651
Fair value of plan assets		610
Progress Energy
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation		679
Accumulated benefit obligation		651
Fair value of plan assets		610
Duke Energy Florida
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation		679
Accumulated benefit obligation		651
Fair value of plan assets		610
Duke Energy Ohio
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	$ 155	123
Accumulated benefit obligation	146	115
Fair value of plan assets	79	69
Duke Energy Indiana
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	260	203
Accumulated benefit obligation	252	199
Fair value of plan assets	$ 177	$ 159