v3.26.1
Investments in Debt and Equity Securities (Maturities) (Details)
$ in Millions
Mar. 31, 2026
USD ($)
Debt Securities, Available-for-sale [Line Items]  
Due in one year or less $ 122
Due after one through five years 1,506
Due after five through 10 years 1,162
Due after 10 years 2,628
Total 5,418
Duke Energy Carolinas  
Debt Securities, Available-for-sale [Line Items]  
Due in one year or less 24
Due after one through five years 814
Due after five through 10 years 633
Due after 10 years 1,468
Total 2,939
Progress Energy  
Debt Securities, Available-for-sale [Line Items]  
Due in one year or less 97
Due after one through five years 630
Due after five through 10 years 482
Due after 10 years 1,048
Total 2,257
Duke Energy Progress  
Debt Securities, Available-for-sale [Line Items]  
Due in one year or less 40
Due after one through five years 602
Due after five through 10 years 465
Due after 10 years 998
Total 2,105
Duke Energy Florida  
Debt Securities, Available-for-sale [Line Items]  
Due in one year or less 57
Due after one through five years 28
Due after five through 10 years 17
Due after 10 years 50
Total 152
Duke Energy Indiana  
Debt Securities, Available-for-sale [Line Items]  
Due in one year or less 1
Due after one through five years 6
Due after five through 10 years 8
Due after 10 years 14
Total $ 29