Commitments and Contingencies Commitments and Contingencies - PAC - Commitments (Details) - PacifiCorp [Member] $ in Millions	Sep. 30, 2018 USD ($)
Long-term Renewable Power Purchase Agreement [Member]
ContractualObligationFiscalYearMaturityScheduleTable [Line Items]
Purchase Obligation	$ 1,000
Capital Addition Purchase Commitments [Member]
ContractualObligationFiscalYearMaturityScheduleTable [Line Items]
Purchase Obligation	566
Public Utilities, Inventory, Fuel [Member]
ContractualObligationFiscalYearMaturityScheduleTable [Line Items]
Purchase Obligation	$ 273