Consolidated Statements of Comprehensive Income (LLC) (MidAmerican Funding, LLC and Subsidiaries [Domain], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
MidAmerican Funding, LLC and Subsidiaries [Domain]
Net income	$ 305	$ 340	$ 328
Other comprehensive income (loss):
Unrealized gains on available-for-sale securities, net of tax of $-, $2 and $-	1	2	0
Unrealized gains (losses) on cash flow hedges, net of tax of $(3), $11 and $6	(6)	18	11
Total other comprehensive income (loss), net of tax	(5)	20	11
Comprehensive income	300	360	339
Comprehensive income attributable to noncontrolling interests	1	0	1
Comprehensive income attributable to MidAmerican Funding	$ 299	$ 360	$ 338