Segment Information (LLC) (Details) (MidAmerican Funding, LLC and Subsidiaries [Domain], USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014 ReportableSegments		Sep. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Number of Reportable Segments				3
Regulated electric	$ 539		$ 512	$ 1,415		$ 1,338
Regulated gas	99		98	746		555
Nonregulated	226		218	708		615
Total operating revenue	864		828	2,869		2,508
Depreciation and amortization	88		97	258		308
Total operating income	161		130	365		279
Assets	14,187	[1]		14,187	[1]		13,167	[1]
Regulated electric [Member]
Segment Reporting Information [Line Items]
Regulated electric	539		512	1,415		1,338
Depreciation and amortization	78		88	229		281
Total operating income	163		130	294		211
Assets	12,761	[1]		12,761	[1]		11,723	[1]
Regulated gas [Member]
Segment Reporting Information [Line Items]
Regulated gas	99		98	746		555
Depreciation and amortization	10		9	29		27
Total operating income	(6)		(6)	49		43
Assets	1,246	[1]		1,246	[1]		1,285	[1]
Nonregulated energy [Member]
Segment Reporting Information [Line Items]
Nonregulated	224		216	695		610
Total operating income	3		6	21		25
Assets	158	[1]		158	[1]		131	[1]
Other [Member]
Segment Reporting Information [Line Items]
Nonregulated	2		2	13		5
Total operating income	1		0	1		0
Assets	$ 22	[1]		$ 22	[1]		$ 28	[1]

[1] (1)Total assets by reportable segment reflect the assignment of goodwill to applicable reporting units.