Asset Retirement Obligation Asset Retirement Obligations (Details) - MidAmerican Energy Company [Member] $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligation, Revision of Estimate	$ 234
Fossil Fuel Plant [Member]
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligation, Revision of Estimate	$ 237

Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 35
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6392603&loc=d3e7123-110846

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(4)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration