Segment Information Segment Information - MEC (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) OperatingSegments ReportableSegments	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | OperatingSegments			8
Revenues	$ 4,993	$ 4,554	$ 9,433	$ 8,720
Operating income	972	1,045	1,843	2,012
Interest expense	(461)	(457)	(927)	(915)
Capitalized interest	15	10	27	20
Allowance for equity funds	24	18	45	35
Other, net	1	(1)	31	25
Income before income tax (benefit) expense and equity income	196	644	481	1,235
Assets	90,941		$ 90,941		$ 90,208
MidAmerican Energy Company [Member]
Segment Reporting Information [Line Items]
Number of reportable segments | ReportableSegments			2
Electric Domestic Regulated Revenue	589	537	$ 1,058	970
Revenues	717	658	1,463	1,353
Operating income	87	130	166	232
Interest expense	(56)	(53)	(114)	(106)
Capitalized interest	4	3	8	5
Allowance for equity funds	13	8	23	14
Other, net	12	7	21	18
Income before income tax (benefit) expense and equity income	60	95	104	163
Assets	16,886		16,886		16,318
MidAmerican Energy Company [Member] | Regulated Electric [Member]
Segment Reporting Information [Line Items]
Electric Domestic Regulated Revenue	589	537	1,058	970
Operating income	78	125	114	188
Assets	15,612		15,612		14,914
MidAmerican Energy Company [Member] | Regulated Gas [Member]
Segment Reporting Information [Line Items]
Gas Domestic Regulated Revenue	127	120	402	382
Operating income	8	5	51	44
Assets	1,274		1,274		1,403
MidAmerican Energy Company [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Other Revenue, Net	1	1	3	1
Operating income	1	$ 0	1	$ 0
Assets	$ 0		$ 0		$ 1