Fair Value Measurements (MEC) (Details) (MidAmerican Energy Company [Member], USD $) | Jun. 30, 2014 | Dec. 31, 2013 |
In Millions, unless otherwise specified |
Collateral and netting [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions | $38 | | $0 | |
Fair Value, Measurements, Recurring [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Commodity derivative assets | 24 | | 2 | |
Assets, Fair Value Disclosure | 556 | | 513 | |
Liabilities - commodity derivatives, fair value | -6 | | -29 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Commodity derivative assets | 3 | | 3 | |
Assets, Fair Value Disclosure | 467 | | 450 | |
Liabilities - commodity derivatives, fair value | -1 | | -1 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Commodity derivative assets | 53 | | 16 | |
Assets, Fair Value Disclosure | 96 | | 57 | |
Liabilities - commodity derivatives, fair value | -73 | | -42 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Commodity derivative assets | 16 | | 6 | |
Assets, Fair Value Disclosure | 41 | | 29 | |
Liabilities - commodity derivatives, fair value | -18 | | -9 | |
Fair Value, Measurements, Recurring [Member] | Collateral and netting [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Commodity derivative assets | -48 | [1] | -23 | [1] |
Assets, Fair Value Disclosure | -48 | [1] | -23 | [1] |
Liabilities - commodity derivatives, fair value | 86 | [1] | 23 | [1] |
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 98 | [2] | 95 | [2] |
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 98 | [2] | 95 | [2] |
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | [2] | 0 | [2] |
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | [2] | 0 | [2] |
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Collateral and netting [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | [1],[2] | 0 | [1],[2] |
United States government obligations [Member] | Fair Value, Measurements, Recurring [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 135 | | 134 | |
United States government obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 135 | | 134 | |
United States government obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
United States government obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
United States government obligations [Member] | Fair Value, Measurements, Recurring [Member] | Collateral and netting [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | [1] | 0 | [1] |
International government obligations [Member] | Fair Value, Measurements, Recurring [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 1 | | 1 | |
International government obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
International government obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 1 | | 1 | |
International government obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
International government obligations [Member] | Fair Value, Measurements, Recurring [Member] | Collateral and netting [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | [1] | 0 | [1] |
Corporate obligations [Member] | Fair Value, Measurements, Recurring [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 38 | | 36 | |
Corporate obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
Corporate obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 38 | | 36 | |
Corporate obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
Corporate obligations [Member] | Fair Value, Measurements, Recurring [Member] | Collateral and netting [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | [1] | 0 | [1] |
Municipal obligations [Member] | Fair Value, Measurements, Recurring [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 2 | | 2 | |
Municipal obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
Municipal obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 2 | | 2 | |
Municipal obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
Municipal obligations [Member] | Fair Value, Measurements, Recurring [Member] | Collateral and netting [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | [1] | 0 | [1] |
Agency, asset and mortgage-backed obligations [Member] | Fair Value, Measurements, Recurring [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 2 | | 2 | |
Agency, asset and mortgage-backed obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
Agency, asset and mortgage-backed obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 2 | | 2 | |
Agency, asset and mortgage-backed obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
Agency, asset and mortgage-backed obligations [Member] | Fair Value, Measurements, Recurring [Member] | Collateral and netting [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | [1] | 0 | [1] |
Auction rate securities [Member] | Fair Value, Measurements, Recurring [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 25 | | 23 | |
Auction rate securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
Auction rate securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
Auction rate securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 25 | | 23 | |
Auction rate securities [Member] | Fair Value, Measurements, Recurring [Member] | Collateral and netting [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | [1] | 0 | [1] |
United States equity securities [Member] | Fair Value, Measurements, Recurring [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 226 | | 214 | |
United States equity securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 226 | | 214 | |
United States equity securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
United States equity securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
United States equity securities [Member] | Fair Value, Measurements, Recurring [Member] | Collateral and netting [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | [1] | 0 | [1] |
International equity securities [Member] | Fair Value, Measurements, Recurring [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 5 | | 4 | |
International equity securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 5 | | 4 | |
International equity securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
International equity securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | 0 | | 0 | |
International equity securities [Member] | Fair Value, Measurements, Recurring [Member] | Collateral and netting [Member] | ' | | ' | |
Assets, Fair Value Disclosure [Abstract] | ' | | ' | |
Available-for-sale Securities, Fair Value Disclosure | $0 | [1] | $0 | [1] |
|
[1] | Represents netting under master netting arrangements and a net cash collateral receivable of $38B million and $-B million as of JuneB 30, 2014 and DecemberB 31, 2013, respectively. |
[2] | Amounts are included in cash and cash equivalents and investments and nonregulated property, net on the Balance Sheets. The fair value of these money market mutual funds approximates cost. |