Segment Information (LLC) (Details) (MidAmerican Funding, LLC and Subsidiaries [Domain], USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014 TheNumberOfReportableSegments	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Number of Reportable Segments									3
Regulated electric revenue									$ 1,817	$ 1,762	$ 1,694
Regulated gas revenue									996	824	659
Nonregulated									949	827	894
Total operating revenue	893	864	775	1,230	905	828	759	921	3,762	3,413	3,247
Total depreciation and amortization									351	403	392
Total operating income	58	161	51	153	78	130	43	106	423	357	369
Total fixed charges									181	167	162
Total income tax (benefit) expense									(110)	(110)	(108)
Total net income attributable to MidAmerican Funding									409	340	342
Total utility construction expenditures									1,526	1,026	645
Total assets	14,544				13,167				14,544	13,167	12,530
Regulated electric [Member]
Segment Reporting Information [Line Items]
Regulated electric revenue									1,817	1,762	1,694
Total depreciation and amortization									312	366	356
Total operating income									319	255	270
Total fixed charges									141	129	123
Total income tax (benefit) expense									(138)	(136)	(129)
Total net income attributable to MidAmerican Funding									361	292	297
Total utility construction expenditures									1,429	945	588
Total assets	13,050				11,723				13,050	11,723	11,089
Regulated gas [Member]
Segment Reporting Information [Line Items]
Regulated gas revenue									996	824	659
Total depreciation and amortization									39	37	36
Total operating income									75	74	47
Total fixed charges									17	15	15
Total income tax (benefit) expense									22	23	7
Total net income attributable to MidAmerican Funding									40	41	28
Total utility construction expenditures									97	81	57
Total assets	1,310				1,285				1,310	1,285	1,280
Nonregulated Energy [Member]
Segment Reporting Information [Line Items]
Nonregulated									927	817	889
Total operating income									28	27	53
Total income tax (benefit) expense									12	10	23
Total net income attributable to MidAmerican Funding									16	16	29
Total assets	167				131				167	131	132
Other [Member]
Segment Reporting Information [Line Items]
Nonregulated									22	10	5
Total operating income									1	1	(1)
Total fixed charges									23	23	24
Total income tax (benefit) expense									(6)	(7)	(9)
Total net income attributable to MidAmerican Funding									(8)	(9)	(12)
Total assets	$ 17				$ 28				$ 17	$ 28	$ 29