Business Segments (Narrative) (Details) $ in Millions	12 Months Ended
Dec. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Loss on sale	$ (10)	$ 4	$ 89
Operation, maintenance and other	5,788	6,066	6,463
Revenues	23,868	25,079	24,521
Duke Energy Progress
Segment Reporting Information [Line Items]
Loss on sale	(8)		(9)
Operation, maintenance and other	1,332	1,446	1,578
Revenues	$ 5,422	5,957	5,699
Number of reportable segments \| segment	1
Duke Energy Ohio
Segment Reporting Information [Line Items]
Loss on sale			106
Operation, maintenance and other	$ 463	520	480
Revenues	$ 1,858	$ 1,940	1,957
Number of reportable segments \| segment	2
Revenues \| Duke Energy Progress \| Customer Concentration \| One customer
Segment Reporting Information [Line Items]
Revenues	$ 553
Beckjord
Segment Reporting Information [Line Items]
Loss on sale			106
Operation, maintenance and other			$ 1

Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8672-108599

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