Income Taxes (MEC) Net Unrecognized Tax Benefits (Details) (MidAmerican Energy Company [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
MidAmerican Energy Company [Member]
Net Unrecognized Tax Benefits [Line Items]
Unrecognized tax benefits that would impact the effective tax rate	$ 26	$ 29
Reconciliation of Net Unrecognized Tax Benefits [Roll Forward]
Beginning balance	29	36
Additions based on tax positions related to current year	6	10
Additions for tax positions of prior years	38	3
Reductions based on tax positions related to the current year	(4)	(10)
Reductions for tax positions of prior years	(40)	(8)
Statute of limitations	(3)	(2)
Ending balance	$ 26	$ 29

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Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

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Amount of decrease in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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