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Employee Benefit Plans (Sensitivity to Changes in Assumed Health Care Cost Trend Rates) (Details) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 USD ($)
Defined Benefit Plan Disclosure [Line Items] |
Effect on total service and interest costs - 1 Percentage Point Increase | $ 1
Effect on post-retirement benefit obligation - 1 Percentage Point Increase | 22
Effect on total service and interest costs - 1 Percentage Point Decrease | (1)
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease | (20)
Duke Energy Carolinas |
Defined Benefit Plan Disclosure [Line Items] |
Effect on total service and interest costs - 1 Percentage Point Increase | 0
Effect on post-retirement benefit obligation - 1 Percentage Point Increase | 5
Effect on total service and interest costs - 1 Percentage Point Decrease | 0
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease | (5)
Progress Energy |
Defined Benefit Plan Disclosure [Line Items] |
Effect on total service and interest costs - 1 Percentage Point Increase | 1
Effect on post-retirement benefit obligation - 1 Percentage Point Increase | 9
Effect on total service and interest costs - 1 Percentage Point Decrease | (1)
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease | (8)
Duke Energy Progress |
Defined Benefit Plan Disclosure [Line Items] |
Effect on total service and interest costs - 1 Percentage Point Increase | 1
Effect on post-retirement benefit obligation - 1 Percentage Point Increase | 5
Effect on total service and interest costs - 1 Percentage Point Decrease | (1)
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease | (4)
Duke Energy Florida |
Defined Benefit Plan Disclosure [Line Items] |
Effect on total service and interest costs - 1 Percentage Point Increase | 0
Effect on post-retirement benefit obligation - 1 Percentage Point Increase | 4
Effect on total service and interest costs - 1 Percentage Point Decrease | 0
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease | (4)
Duke Energy Ohio |
Defined Benefit Plan Disclosure [Line Items] |
Effect on total service and interest costs - 1 Percentage Point Increase | 0
Effect on post-retirement benefit obligation - 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 Decrease | (1)
Duke Energy Indiana |
Defined Benefit Plan Disclosure [Line Items] |
Effect on total service and interest costs - 1 Percentage Point Increase | 0
Effect on post-retirement benefit obligation - 1 Percentage Point Increase | 2
Effect on total service and interest costs - 1 Percentage Point Decrease | 0
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease | (2)
Piedmont |
Defined Benefit Plan Disclosure [Line Items] |
Effect on total service and interest costs - 1 Percentage Point Increase | 0
Effect on post-retirement benefit obligation - 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 Decrease | $ (1)

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