Regulatory Matters (Regulatory Matters Narrative - Duke Energy Indiana) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended		12 Months Ended
	Apr. 04, 2024	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2026	Dec. 31, 2025	Sep. 20, 2023	Jun. 15, 2022
Public Utilities, General Disclosures [Line Items]
Impairment of assets and other charges		$ 43	$ 0	$ 44	$ 8
Operating Revenues		7,172	6,578	14,843	13,854
Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Operating Revenues		$ 747	$ 780	$ 1,506	$ 1,755
Indiana Coal Ash Recovery | IURC | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Interest rate on refunds (as a percent)								4.71%
TDSIG 2.0 | IURC | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Future investment in infrastructure									$ 2,000
2024 Indiana Rate Case | IURC | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Future investment in infrastructure	$ 1,600
Requested rate increase (decrease), amount	$ 492
Requested rate increase, percentage, net of tax	16.20%
Requested return on equity (as a percent)	10.50%
Equity ratio (as a percent)	53.00%
2024 Indiana Rate Case | IURC | Duke Energy Indiana | Forecast
Public Utilities, General Disclosures [Line Items]
Requested rate increase, percentage, net of tax						4.50%	11.70%