Regulatory Matters (Duke Energy Ohio - Exit Obligation Rollforward) (Details) $ in Millions	12 Months Ended
Dec. 31, 2020 USD ($)
Public Utilities, General Disclosures [Line Items]
Balance, beginning of period	$ 41
Cash reductions	(31)
Balance, end of period	11
Duke Energy Ohio
Public Utilities, General Disclosures [Line Items]
Balance, beginning of period	1
RTO Realignment \| Duke Energy Ohio
Public Utilities, General Disclosures [Line Items]
Balance, beginning of period	54
Provisions/Adjustments	(1)
Cash reductions	(3)
Balance, end of period	$ 50

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

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