Consolidated Statements of Changes in Equity (LLC) (MidAmerican Funding, LLC and Subsidiaries [Domain], USD $) In Millions, unless otherwise specified	MidAmerican Funding, LLC and Subsidiaries [Domain] USD ($)	MidAmerican Funding, LLC and Subsidiaries [Domain] Additional Paid-in Capital [Member] USD ($)	MidAmerican Funding, LLC and Subsidiaries [Domain] Retained Earnings [Member] USD ($)	MidAmerican Funding, LLC and Subsidiaries [Domain] Accumulated Other Comprehensive Income (Loss) [Member] USD ($)	MidAmerican Funding, LLC and Subsidiaries [Domain] Noncontrolling Interest [Member] USD ($)
Balance at Dec. 31, 2009	$ 3,459	$ 1,679	$ 1,798	$ (49)	$ 31
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	340		340		0
Other comprehensive income (loss)	20			20
Repurchase of preferred securities of subsidiary	(2)				(2)
Distribution to member	(114)		(114)
Distributions to noncontrolling interests	(1)				(1)
Other equity transactions	(1)		(1)
Balance at Dec. 31, 2010	3,701	1,679	2,023	(29)	28
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	69
Balance at Mar. 31, 2011
Balance at Dec. 31, 2010	3,701	1,679	2,023	(29)	28
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	305		304		1
Other comprehensive income (loss)	(5)			(5)
Distribution to member	0
Distributions to noncontrolling interests	(1)				(1)
Balance at Dec. 31, 2011	4,000	1,679	2,327	(34)	28
Balance at Sep. 30, 2011
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	87
Balance at Dec. 31, 2011	4,000	1,679
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	71
Balance at Mar. 31, 2012
Balance at Dec. 31, 2011	4,000	1,679	2,327	(34)	28
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	343		342		1
Other comprehensive income (loss)	10			10
Distribution to member	0
Distributions to noncontrolling interests	(1)				(1)
Disposition of subsidiary	(1)				(1)
Balance at Dec. 31, 2012	4,351	1,679	2,669	(24)	27
Balance at Sep. 30, 2012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	58
Balance at Dec. 31, 2012	$ 4,351	$ 1,679