Utility Plant and Nonutility Property (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Utility Plant And Non Utility Property [Line Items]
Amounts due from Santee Cooper for share of direct expenses	$ 97	$ 141
Summer [Member]
Utility Plant And Non Utility Property [Line Items]
Amounts due from Santee Cooper for share of direct expenses	$ 50	$ 21

Amount, after allowance, receivable from customers, clients, or other third-parties, and receivables classified as other due within one year or the normal operating cycle, if longer.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant