Risk Management and Hedging Activities (MEC) Balance Sheet Location (Details) - MidAmerican Energy Company [Member] - Commodity Contract [Member] - USD ($) $ in Millions		Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Total derivative assets (liabilities), net		$ (68)		$ (74)
Cash collateral, net receivable (payable), offset against derivatives		31		47
Total derivatives - net of collateral		(37)		(27)
Current Assets - Other [Member]
Derivatives, Fair Value [Line Items]
Total derivative assets (liabilities), net		10		14
Cash collateral, net receivable (payable), offset against derivatives		0		0
Total derivatives - net of collateral		10		14
Other Assets - Other [Member]
Derivatives, Fair Value [Line Items]
Total derivative assets (liabilities), net		3		3
Cash collateral, net receivable (payable), offset against derivatives		0		0
Total derivatives - net of collateral		3		3
Current Liabilities - Other [Member]
Derivatives, Fair Value [Line Items]
Total derivative assets (liabilities), net		(58)		(73)
Cash collateral, net receivable (payable), offset against derivatives		26		42
Total derivatives - net of collateral		(32)		(31)
Other Liabilities - Other [Member]
Derivatives, Fair Value [Line Items]
Total derivative assets (liabilities), net		(23)		(18)
Cash collateral, net receivable (payable), offset against derivatives		5		5
Total derivatives - net of collateral		(18)		(13)
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	[1]	29		37
Commodity liabilities	[1]	(57)		(73)
Total derivative assets (liabilities), net	[1]	(28)		(36)
Net regulatory asset		28	$ 18	38	$ 48	$ 32	$ 10
Not Designated as Hedging Instrument [Member] | Current Assets - Other [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	[1]	11		14
Commodity liabilities	[1]	(1)		0
Total derivative assets (liabilities), net	[1]	10		14
Not Designated as Hedging Instrument [Member] | Other Assets - Other [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	[1]	3		3
Commodity liabilities	[1]	0		0
Total derivative assets (liabilities), net	[1]	3		3
Not Designated as Hedging Instrument [Member] | Current Liabilities - Other [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	[1]	15		19
Commodity liabilities	[1]	(51)		(69)
Total derivative assets (liabilities), net	[1]	(36)		(50)
Not Designated as Hedging Instrument [Member] | Other Liabilities - Other [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	[1]	0		1
Commodity liabilities	[1]	(5)		(4)
Total derivative assets (liabilities), net	[1]	(5)		(3)
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Commodity assets		4		6
Commodity liabilities		(44)		(44)
Total derivative assets (liabilities), net		(40)		(38)
Designated as Hedging Instrument [Member] | Current Assets - Other [Member]
Derivatives, Fair Value [Line Items]
Commodity assets		0		0
Commodity liabilities		0		0
Total derivative assets (liabilities), net		0		0
Designated as Hedging Instrument [Member] | Other Assets - Other [Member]
Derivatives, Fair Value [Line Items]
Commodity assets		0		0
Commodity liabilities		0		0
Total derivative assets (liabilities), net		0		0
Designated as Hedging Instrument [Member] | Current Liabilities - Other [Member]
Derivatives, Fair Value [Line Items]
Commodity assets		2		4
Commodity liabilities		(24)		(27)
Total derivative assets (liabilities), net		(22)		(23)
Designated as Hedging Instrument [Member] | Other Liabilities - Other [Member]
Derivatives, Fair Value [Line Items]
Commodity assets		2		2
Commodity liabilities		(20)		(17)
Total derivative assets (liabilities), net		$ (18)		$ (15)

[1] MidAmerican Energy's commodity derivatives not designated as hedging contracts are generally included in regulated rates, and as of June 30, 2015 and December 31, 2014, a net regulatory asset of $28 million and $38 million, respectively, was recorded related to the net derivative liability of $28 million and $36 million, respectively.