Summary of Significant Accounting Policies (Noncontrolling Interest) (Details) - Noncontrolling Interests $ in Millions	1 Months Ended	3 Months Ended
	Jan. 31, 2021 USD ($)	Sep. 30, 2019 USD ($) asset	Jan. 31, 2023	Jun. 30, 2021
Duke Energy Indiana [Member] | Subsequent Event
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Value of sale of parent interest	$ 2,000
Percentage sold	19.90%
Holding company ownership of interest	100.00%
Ownership interest sold			19.90%	11.10%
Proceed of purchase price for exchange in interest			50.00%	50.00%
Renewables
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Value of sale of parent interest		$ 415
Ownership interest change		466
Tax benefit from sale of interest		$ 8
Wind and Solar Storage
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Percentage sold		49.00%
Number of assets sold | asset		37
Operating Solar Assets
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Percentage sold		33.00%
Number of assets sold | asset		11