Risk Management and Hedging Activities (MEC) (Tables) (MidAmerican Energy Company and Subsidiaries [Member])

12 Months Ended

Dec. 31, 2012

MidAmerican Energy Company and Subsidiaries [Member]

Derivatives, Fair Value [Line Items]

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]

The following table, which reflects master netting arrangements and excludes contracts that have been designated as normal under the normal purchases or normal sales exception afforded by GAAP, summarizes the fair value of MidAmerican Energy's derivative contracts, on a gross basis, and reconciles those amounts to the amounts presented on a net basis on the Consolidated Balance Sheets (in millions):

	Current			Other			Current			Other
	Assets			Assets			Liabilities			Liabilities
	- Other			- Other			- Other			- Other			Total
As of As of December 31, 2012
Not designated as hedging contracts(1):
Commodity assets	$	18		$	1		$	7		$	2		$	28
Commodity liabilities	(12		)	—			(47		)	(14		)	(73		)
Total	6			1			(40		)	(12		)	(45		)
Designated as hedging contracts:
Commodity assets	—			—			1			1			2
Commodity liabilities	—			—			(22		)	(12		)	(34		)
Total	—			—			(21		)	(11		)	(32		)
Total derivatives	6			1			(61		)	(23		)	(77		)
Cash collateral receivable	—			—			6			1			7
Total derivatives - net basis	$	6		$	1		$	(55	)	$	(22	)	$	(70	)
As of As of December 31, 2011
Not designated as hedging contracts(1):
Commodity assets	$	60		$	6		$	6		$	1		$	73
Commodity liabilities	(29		)	(2		)	(73		)	(41		)	(145		)
Total	31			4			(67		)	(40		)	(72		)
Designated as hedging contracts:
Commodity assets	—			—			1			—			1
Commodity liabilities	(6		)	—			(21		)	(17		)	(44		)
Total	(6		)	—			(20		)	(17		)	(43		)
Total derivatives	25			4			(87		)	(57		)	(115		)
Cash collateral receivable	—			—			28			5			33
Total derivatives - net basis	$	25		$	4		$	(59	)	$	(52	)	$	(82	)

(1) MidAmerican Energy's commodity derivatives not designated as hedging contracts are generally included in regulated rates. Accordingly, as of December 31, 2012 and 2011, a net regulatory asset of $45 million and $73 million, respectively, was recorded related to the net derivative liability of $45 million and $72 million, respectively.

Schedule of Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Contracts [Table Text Block]

The following table reconciles the beginning and ending balances of MidAmerican Energy's net regulatory assets (liabilities) and summarizes the pre-tax gains and losses on commodity derivative contracts recognized in net regulatory assets (liabilities), as well as amounts reclassified to earnings for the years ended December 31 (in millions):

	2012			2011			2010
Beginning balance	$	73		$	27		$	(14	)
Changes in fair value recognized in net regulatory assets (liabilities)	14			76			23
Net gains reclassified to operating revenue	21			—			16
Net gains reclassified to cost of fuel, energy and capacity	2			8			18
Net losses reclassified to cost of gas sold	(65		)	(38		)	(16		)
Ending balance	$	45		$	73		$	27

Schedule Of Nonregulated Derivatives Not Designated As Hedging Instruments Gain (Loss) In Statement Of Financial Performance [Table Text Block]

The following table summarizes the pre-tax gains (losses) included on the Consolidated Statements of Operations associated with MidAmerican Energy's derivative contracts not designated as hedging contracts and not recorded as a net regulatory asset or liability for the years ended December 31 (in millions):

	2012			2011			2010
Nonregulated operating revenue	$	8		$	18		$	20
Regulated cost of gas sold	—			—			3
Nonregulated cost of sales	(4		)	(13		)	(15		)
Total	$	4		$	5		$	8

Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]

The following table reconciles the beginning and ending balances of MidAmerican Energy's accumulated other comprehensive loss (pre-tax) and summarizes pre-tax gains and losses on derivative contracts designated and qualifying as cash flow hedges recognized in OCI, as well as amounts reclassified to earnings, for the years ended December 31 (in millions):

	2012			2011			2010
Beginning balance	$	43		$	34		$	63
Net losses recognized in OCI	27			27			14
Net losses reclassified to nonregulated cost of sales	(38		)	(18		)	(43		)
Ending balance	$	32		$	43		$	34

Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]

The following table summarizes the net notional amounts of outstanding derivative contracts with fixed price terms that comprise the mark-to-market values as of December 31 (in millions):

	Unit of
	Measure	2012	2011
Electricity purchases	Megawatt hours	5	8
Natural gas purchases	Decatherms	36	62
Fuel purchases	Gallons	—	2