v3.26.1
Derivatives and Hedging (Location and Fair Value Amounts of Derivatives Reflected in the Condensed Consolidated Balance Sheets) (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Derivatives, Fair Value [Line Items]    
Derivative assets $ 327 $ 382
Derivative liabilities 283 244
Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 106 116
Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 221 266
Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 172 131
Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 111 113
Commodity Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 39 56
Derivative liabilities 247 210
Interest Rate Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 181 170
Derivative liabilities 7 7
Foreign Currency Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 107 156
Derivative liabilities 29 27
Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 26  
Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 20  
Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   25
Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   20
Derivative liabilities 1  
Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 107  
Designated as Hedging Instruments | Foreign Currency Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 29 27
Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   156
Not Designated as Hedging Instruments | Commodity Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 18 28
Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 21 28
Not Designated as Hedging Instruments | Commodity Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 138 104
Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 109 106
Not Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 62 63
Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 73 62
Not Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 5 0
Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 1 7
Duke Energy Carolinas    
Derivatives, Fair Value [Line Items]    
Derivative assets 99 101
Derivative liabilities 102 88
Duke Energy Carolinas | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 38 43
Duke Energy Carolinas | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 61 58
Duke Energy Carolinas | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 71 56
Duke Energy Carolinas | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 31 32
Duke Energy Carolinas | Commodity Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 13 21
Derivative liabilities 99 85
Duke Energy Carolinas | Interest Rate Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 86 80
Derivative liabilities 3 3
Duke Energy Carolinas | Foreign Currency Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 0 0
Duke Energy Carolinas | Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Carolinas | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Carolinas | Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Duke Energy Carolinas | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Derivative liabilities 0  
Duke Energy Carolinas | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Carolinas | Designated as Hedging Instruments | Foreign Currency Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Carolinas | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Duke Energy Carolinas | Not Designated as Hedging Instruments | Commodity Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 4 9
Duke Energy Carolinas | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 9 12
Duke Energy Carolinas | Not Designated as Hedging Instruments | Commodity Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 68 53
Duke Energy Carolinas | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 31 32
Duke Energy Carolinas | Not Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 34 34
Duke Energy Carolinas | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 52 46
Duke Energy Carolinas | Not Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 3 3
Duke Energy Carolinas | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Progress Energy    
Derivatives, Fair Value [Line Items]    
Derivative assets 66 67
Derivative liabilities 73 48
Progress Energy | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 34 36
Progress Energy | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 32 31
Progress Energy | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 46 21
Progress Energy | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 27 27
Progress Energy | Commodity Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 19 23
Derivative liabilities 70 46
Progress Energy | Interest Rate Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 47 44
Derivative liabilities 3 2
Progress Energy | Foreign Currency Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 0 0
Progress Energy | Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Progress Energy | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Progress Energy | Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Progress Energy | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Derivative liabilities 0  
Progress Energy | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Progress Energy | Designated as Hedging Instruments | Foreign Currency Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Progress Energy | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Progress Energy | Not Designated as Hedging Instruments | Commodity Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 7 7
Progress Energy | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 12 16
Progress Energy | Not Designated as Hedging Instruments | Commodity Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 44 25
Progress Energy | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 26 21
Progress Energy | Not Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 27 29
Progress Energy | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 20 15
Progress Energy | Not Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 2 (4)
Progress Energy | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 1 6
Duke Energy Progress    
Derivatives, Fair Value [Line Items]    
Derivative assets 45 52
Derivative liabilities 70 47
Duke Energy Progress | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 33 36
Duke Energy Progress | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 12 16
Duke Energy Progress | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 44 20
Duke Energy Progress | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 26 27
Duke Energy Progress | Commodity Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 19 23
Derivative liabilities 69 46
Duke Energy Progress | Interest Rate Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 26 29
Derivative liabilities 1 1
Duke Energy Progress | Foreign Currency Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 0 0
Duke Energy Progress | Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Progress | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Progress | Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Duke Energy Progress | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Derivative liabilities 0  
Duke Energy Progress | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Progress | Designated as Hedging Instruments | Foreign Currency Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Progress | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Duke Energy Progress | Not Designated as Hedging Instruments | Commodity Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 7 7
Duke Energy Progress | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 12 16
Duke Energy Progress | Not Designated as Hedging Instruments | Commodity Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 43 25
Duke Energy Progress | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 26 21
Duke Energy Progress | Not Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 26 29
Duke Energy Progress | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Duke Energy Progress | Not Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 1 (5)
Duke Energy Progress | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 6
Duke Energy Florida    
Derivatives, Fair Value [Line Items]    
Derivative assets 21 15
Derivative liabilities 3 1
Duke Energy Florida | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 1 1
Duke Energy Florida | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 20 14
Duke Energy Florida | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 2 1
Duke Energy Florida | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 1 0
Duke Energy Florida | Commodity Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 2 0
Duke Energy Florida | Interest Rate Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 21 15
Derivative liabilities 1 1
Duke Energy Florida | Foreign Currency Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 0 0
Duke Energy Florida | Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Florida | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Florida | Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Duke Energy Florida | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Derivative liabilities 0  
Duke Energy Florida | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Florida | Designated as Hedging Instruments | Foreign Currency Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Florida | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Duke Energy Florida | Not Designated as Hedging Instruments | Commodity Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Duke Energy Florida | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Duke Energy Florida | Not Designated as Hedging Instruments | Commodity Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 2 0
Duke Energy Florida | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Florida | Not Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 1 1
Duke Energy Florida | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 20 14
Duke Energy Florida | Not Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 1
Duke Energy Florida | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 1 0
Duke Energy Ohio    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 0 1
Duke Energy Ohio | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Duke Energy Ohio | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Duke Energy Ohio | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Ohio | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 1
Duke Energy Ohio | Commodity Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 0 0
Duke Energy Ohio | Interest Rate Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 0 1
Duke Energy Ohio | Foreign Currency Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 0 0
Duke Energy Ohio | Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Ohio | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Ohio | Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Duke Energy Ohio | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Derivative liabilities 0  
Duke Energy Ohio | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Ohio | Designated as Hedging Instruments | Foreign Currency Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Ohio | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Duke Energy Ohio | Not Designated as Hedging Instruments | Commodity Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Duke Energy Ohio | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Duke Energy Ohio | Not Designated as Hedging Instruments | Commodity Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Ohio | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Ohio | Not Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Duke Energy Ohio | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Duke Energy Ohio | Not Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Ohio | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 1
Duke Energy Indiana    
Derivatives, Fair Value [Line Items]    
Derivative assets 9 12
Derivative liabilities 10 9
Duke Energy Indiana | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 7 11
Duke Energy Indiana | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 2 1
Duke Energy Indiana | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 10 9
Duke Energy Indiana | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Indiana | Commodity Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 7 11
Derivative liabilities 10 7
Duke Energy Indiana | Interest Rate Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 2 1
Derivative liabilities 0 2
Duke Energy Indiana | Foreign Currency Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 0 0
Duke Energy Indiana | Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Indiana | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Indiana | Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Duke Energy Indiana | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Derivative liabilities 0  
Duke Energy Indiana | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Duke Energy Indiana | Designated as Hedging Instruments | Foreign Currency Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Indiana | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Duke Energy Indiana | Not Designated as Hedging Instruments | Commodity Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 7 11
Duke Energy Indiana | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Duke Energy Indiana | Not Designated as Hedging Instruments | Commodity Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 10 7
Duke Energy Indiana | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Duke Energy Indiana | Not Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Duke Energy Indiana | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 2 1
Duke Energy Indiana | Not Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 2
Duke Energy Indiana | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Piedmont    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 68 72
Piedmont | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Piedmont | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Piedmont | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 16 19
Piedmont | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 52 53
Piedmont | Commodity Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 68 72
Piedmont | Interest Rate Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 0 0
Piedmont | Foreign Currency Contracts    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Derivative liabilities 0 0
Piedmont | Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Piedmont | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Piedmont | Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Piedmont | Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Derivative liabilities 0  
Piedmont | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0  
Piedmont | Designated as Hedging Instruments | Foreign Currency Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Piedmont | Designated as Hedging Instruments | Foreign Currency Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets   0
Piedmont | Not Designated as Hedging Instruments | Commodity Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Piedmont | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Piedmont | Not Designated as Hedging Instruments | Commodity Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 16 19
Piedmont | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 52 53
Piedmont | Not Designated as Hedging Instruments | Interest Rate Contracts | Current assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Piedmont | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets    
Derivatives, Fair Value [Line Items]    
Derivative assets 0 0
Piedmont | Not Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 0 0
Piedmont | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities $ 0 $ 0