Segment Information (LLC) (Details) - MidAmerican Funding, LLC and Subsidiaries [Domain] $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) ReportableSegments	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | ReportableSegments				3
Regulated electric		$ 461	$ 426	$ 887	$ 876
Regulated gas		110	136	405	647
Nonregulated		226	213	456	482
Total operating revenue		797	775	1,748	2,005
Depreciation and amortization		99	85	199	170
Total operating income		122	51	229	204
Assets	[1]	14,845		14,845		$ 14,544
Regulated electric [Member]
Segment Reporting Information [Line Items]
Regulated electric		461	426	887	876
Depreciation and amortization		89	76	179	151
Total operating income		108	48	161	131
Assets	[1]	13,411		13,411		13,050
Regulated gas [Member]
Segment Reporting Information [Line Items]
Regulated gas		110	136	405	647
Depreciation and amortization		10	9	20	19
Total operating income		4	(3)	51	55
Assets	[1]	1,244		1,244		1,310
Nonregulated energy [Member]
Segment Reporting Information [Line Items]
Nonregulated		222	207	447	471
Total operating income		10	6	16	18
Assets	[1]	174		174		167
Other [Member]
Segment Reporting Information [Line Items]
Nonregulated		4	6	9	11
Total operating income		0	$ 0	1	$ 0
Assets	[1]	$ 16		$ 16		$ 17

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