Summary of Significant Accounting Policies (Inventory) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Public Utilities, Inventory [Line Items]
Materials and supplies	$ 3,086	$ 2,604
Coal	842	620
Natural gas, oil and other	364	360
Total inventory	4,292	3,584
Duke Energy Carolinas
Public Utilities, Inventory [Line Items]
Materials and supplies	1,075	876
Coal	364	253
Natural gas, oil and other	45	35
Total inventory	1,484	1,164
Progress Energy
Public Utilities, Inventory [Line Items]
Materials and supplies	1,465	1,232
Coal	231	190
Natural gas, oil and other	205	157
Total inventory	1,901	1,579
Duke Energy Progress
Public Utilities, Inventory [Line Items]
Materials and supplies	963	819
Coal	154	99
Natural gas, oil and other	110	88
Total inventory	1,227	1,006
Duke Energy Florida
Public Utilities, Inventory [Line Items]
Materials and supplies	502	413
Coal	77	91
Natural gas, oil and other	95	69
Total inventory	674	573
Duke Energy Ohio
Public Utilities, Inventory [Line Items]
Materials and supplies	139	105
Coal	28	34
Natural gas, oil and other	12	5
Total inventory	179	144
Duke Energy Indiana
Public Utilities, Inventory [Line Items]
Materials and supplies	361	342
Coal	219	144
Natural gas, oil and other	2	3
Total inventory	582	489
Piedmont
Public Utilities, Inventory [Line Items]
Materials and supplies	12	12
Natural gas, oil and other	100	160
Total inventory	$ 112	$ 172