Risk Management and Hedging Activities - MEC - Balance Sheet Location (Details) - USD ($) $ in Millions		Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		$ (171)		$ (237)
Cash collateral, net receivable, offset against derivative positions		81		103
Derivative assets (liabilities), at fair value, net		(90)		(134)
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		35		28
Cash collateral, net receivable, offset against derivative positions		0		0
Derivative assets (liabilities), at fair value, net		35		28
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		74		75
Cash collateral, net receivable, offset against derivative positions		0		0
Derivative assets (liabilities), at fair value, net		74		75
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(92)		(145)
Cash collateral, net receivable, offset against derivative positions		23		40
Derivative assets (liabilities), at fair value, net		(69)		(105)
Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(188)		(195)
Cash collateral, net receivable, offset against derivative positions		58		63
Derivative assets (liabilities), at fair value, net		(130)		(132)
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(131)		(188)
Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		34		28
Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		74		72
Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(69)		(109)
Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(170)		(179)
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(40)		(49)
Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		1		0
Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		0		3
Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(23)		(36)
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(18)		(16)
Commodity derivative [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Net Regulatory Asset (Liability), Unrealized Loss (Gain) On Derivative Contracts		185	$ 253	250	$ 233	$ 255	$ 223
Derivative asset, fair value, gross asset including not subject to master netting arrangement		114		106
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		233		292
Derivative, fair value, net		(119)		(186)
Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		24		25
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		4		4
Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		75		72
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		1		0
Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		14		7
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		72		113
Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		1		2
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		156		175
Commodity derivative [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		7		3
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		32		50
Commodity derivative [Member] | Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		1		0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0		0
Commodity derivative [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		0		0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0		0
Commodity derivative [Member] | Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		3		1
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		21		33
Commodity derivative [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		3		2
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		11		17
MidAmerican Energy Company [Member] | Commodity derivative [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(1)		(72)
Cash collateral, net receivable, offset against derivative positions		4		28
Derivative assets (liabilities), at fair value, net		3		(44)
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		6		9
Cash collateral, net receivable, offset against derivative positions		0		0
Derivative assets (liabilities), at fair value, net		6		9
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		0		4
Cash collateral, net receivable, offset against derivative positions		0		0
Derivative assets (liabilities), at fair value, net		0		4
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(6)		(62)
Cash collateral, net receivable, offset against derivative positions		4		22
Derivative assets (liabilities), at fair value, net		(2)		(40)
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(1)		(23)
Cash collateral, net receivable, offset against derivative positions		0		6
Derivative assets (liabilities), at fair value, net		(1)		(17)
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Net Regulatory Asset (Liability), Unrealized Loss (Gain) On Derivative Contracts		3	$ 11	20	$ 28	$ 18	$ 38
Derivative asset, fair value, gross asset including not subject to master netting arrangement	[1]	8		23
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	9		49
Derivative, fair value, net	[1]	(1)		(26)
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	[1]	6		12
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	0		3
Derivative, fair value, net	[1]	6		9
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	[1]	0		4
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	0		0
Derivative, fair value, net	[1]	0		4
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	[1]	2		5
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	8		36
Derivative, fair value, net	[1]	(6)		(31)
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	[1]	0		2
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	1		10
Derivative, fair value, net	[1]	(1)		(8)
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		0		3
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0		49
Derivative, fair value, net		0		(46)
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		0		0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0		0
Derivative, fair value, net		0		0
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		0		0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0		0
Derivative, fair value, net		0		0
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		0		1
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0		32
Derivative, fair value, net		0		(31)
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement		0		2
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0		17
Derivative, fair value, net		$ 0		$ (15)

[1] (1)MidAmerican Energy's commodity derivatives not designated as hedging contracts are generally included in regulated rates, and as of June 30, 2016 and December 31, 2015, a net regulatory asset of $3 million and $20 million, respectively, was recorded related to the net derivative liability of $1 million and $26 million, respectively.