Income Taxes Income Taxes - MEC - Summary of Operating Loss Carryforwards (Details) - MidAmerican Energy Company [Member] $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($)
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Federal, state and foreign carryforwards	$ 23
Operating Loss Carryforwards	$ 488
Minimum [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss and Tax Credit Carry Forwards, Domestic Federal and State, ExpirationDate	2016
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss and Tax Credit Carry Forwards, Domestic Federal and State, ExpirationDate	2034

The expiration date of domestic federal and state operating loss and tax credit carryforwards.

No definition available.

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Namespace Prefix:	mec_
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Period Type:	duration

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible domestic federal and state operating loss and tax credit carryforwards.

+ References

No definition available.

+ Details

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Namespace Prefix:	mec_
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Period Type:	instant

- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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