Commitments and Contingencies Commitments and Contingencies - MEC- Commitments (Details) - MidAmerican Energy Company [Member] $ in Millions	Sep. 30, 2020 USD ($)
Capital Addition Purchase Commitments [Member]
ContractualObligationFiscalYearMaturityScheduleTable [Line Items]
Purchase Obligation	$ 274
Maintenance, service and other contracts [Member]
ContractualObligationFiscalYearMaturityScheduleTable [Line Items]
Purchase Obligation	75
Easements [Member]
ContractualObligationFiscalYearMaturityScheduleTable [Line Items]
Purchase Obligation	$ 102