Risk Management and Hedging Activities - MEC - Balance Sheet Location (Details) - USD ($) $ in Millions		Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		$ (264)	$ (237)
Cash collateral, net receivable, offset against derivative positions		113	103
Derivative assets (liabilities), at fair value, net		(151)	(134)
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		30	28
Cash collateral, net receivable, offset against derivative positions		0	0
Derivative assets (liabilities), at fair value, net		30	28
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		85	75
Cash collateral, net receivable, offset against derivative positions		0	0
Derivative assets (liabilities), at fair value, net		85	75
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(162)	(145)
Cash collateral, net receivable, offset against derivative positions		47	40
Derivative assets (liabilities), at fair value, net		(115)	(105)
Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(217)	(195)
Cash collateral, net receivable, offset against derivative positions		66	63
Derivative assets (liabilities), at fair value, net		(151)	(132)
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(180)	(188)
Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		30	28
Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		85	72
Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(111)	(109)
Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(184)	(179)
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(84)	(49)
Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		0	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		(51)	(36)
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(33)	(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		253	250	$ 255	$ 223
Derivative asset, fair value, gross asset including not subject to master netting arrangement		118	106
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		292	292
Derivative, fair value, net		(174)	(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		20	25
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		1	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		85	72
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	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		11	7
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		117	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		2	2
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		174	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		0	3
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		73	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		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 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		0	1
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		47	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		0	2
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		26	17
MidAmerican Energy Company [Member] | Commodity derivative [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		(8)	(72)
Cash collateral, net receivable, offset against derivative positions		6	28
Derivative assets (liabilities), at fair value, net		(2)	(44)
MidAmerican Energy Company [Member] | Commodity derivative [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net		3	9
Cash collateral, net receivable, offset against derivative positions		0	0
Derivative assets (liabilities), at fair value, net		3	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		(10)	(62)
Cash collateral, net receivable, offset against derivative positions		6	22
Derivative assets (liabilities), at fair value, net		(4)	(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		11	20	$ 18	$ 38
Derivative asset, fair value, gross asset including not subject to master netting arrangement	[1]	4	23
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	12	49
Derivative, fair value, net	[1]	(8)	(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]	3	12
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	0	3
Derivative, fair value, net	[1]	3	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]	1	5
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	11	36
Derivative, fair value, net	[1]	(10)	(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 March 31, 2016 and December 31, 2015, a net regulatory asset of $11 million and $20 million, respectively, was recorded related to the net derivative liability of $8 million and $26 million, respectively.