Joint Ownership of Generating and Transmission Facilities (Schedule Joint Ownership of Generating and Transmission Facilities) (Details) $ in Millions	Dec. 31, 2019 USD ($)
Duke Energy Carolinas \| Catawba (units 1 and 2)
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	19.25%
Property, plant, and equipment	$ 1,011
Accumulated depreciation	510
Construction work in progress	$ 21
Duke Energy Carolinas \| W.S. Lee CC
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	87.27%
Property, plant, and equipment	$ 609
Accumulated depreciation	32
Construction work in progress	$ 1
Duke Energy Indiana \| Gibson (unit 5)
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	50.05%
Property, plant, and equipment	$ 410
Accumulated depreciation	183
Construction work in progress	$ 3
Duke Energy Indiana \| Vermillion
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	62.50%
Property, plant, and equipment	$ 172
Accumulated depreciation	119
Duke Energy Indiana \| Transmission and local facilities
Jointly Owned Utility Plant Interests [Line Items]
Property, plant, and equipment	5,421
Accumulated depreciation	1,436
Construction work in progress	$ 172

The period end amount owned by the reporting utility of a jointly owned utility plant in service.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 10.C)
-URI http://asc.fasb.org/extlink&oid=115995737&loc=d3e659983-123033

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

The period end amount of construction work in progress at a jointly owned electricity generation plant.

+ References

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- Definition

The period end amount of accumulated depreciation in a jointly owned electricity generation plant.

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- Definition

The proportionate share of interest (percent) in a jointly owned utility plant.

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