Subsidiary Debt - SPPC (Details) $ in Billions	Dec. 31, 2020 USD ($)
Sierra Pacific Power Company [Member]
Debt Instrument [Line Items]
Eligible Property Subject To Lien Of Mortgages	$ 4.3

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.

No definition available.

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