Segment Information Segment Information - MEC (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($) OperatingSegments ReportableSegments	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | OperatingSegments	8
Operating revenue	$ 4,610	$ 4,440
Operating income	919	871
Interest expense	(477)	(466)
Capitalized interest	16	12
Allowance for equity funds	32	21
Other, net	35	30
Income before income tax (benefit) expense and equity income	487	285
Assets	$ 94,545		$ 92,189
MidAmerican Energy Company [Member]
Segment Reporting Information [Line Items]
Number of reportable segments | ReportableSegments	2
Operating revenue	$ 842	746
Operating income	115	79
Interest expense	(69)	(58)
Capitalized interest	6	4
Allowance for equity funds	15	10
Other, net	20	9
Income before income tax (benefit) expense and equity income	87	44
Assets	18,732		17,920
MidAmerican Energy Company [Member] | Regulated electric
Segment Reporting Information [Line Items]
Operating revenue	542	469
Operating income	66	36
Assets	17,373		16,511
MidAmerican Energy Company [Member] | Regulated natural gas
Segment Reporting Information [Line Items]
Operating revenue	295	275
Operating income	48	43
Assets	1,357		1,406
MidAmerican Energy Company [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating revenue	5	2
Operating income	1	$ 0
Assets	$ 2		$ 3