Statements of Changes in Equity (MEC) (MidAmerican Energy Company [Member], USD $) In Millions, unless otherwise specified	MidAmerican Energy Company [Member] USD ($)	MidAmerican Energy Company [Member] Common Stock [Member] USD ($)	MidAmerican Energy Company [Member] Retained Earnings [Member] USD ($)	MidAmerican Energy Company [Member] Accumulated Other Comprehensive Loss, Net [Member] USD ($)	MidAmerican Energy Company [Member] Preferred Securities [Member] USD ($)	MidAmerican Energy Company [Member] Noncontrolling Interests [Member] USD ($)
Balance at Dec. 31, 2011	$ 3,272	$ 562	$ 2,716	$ (34)	$ 27	$ 1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	74		74			0
Other comprehensive income (loss)	(14)			(14)		0
Balance at Mar. 31, 2012	3,332	562	2,790	(48)	27	1
Balance at Dec. 31, 2012	3,635	562	3,070	(24)	27	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	103		103			0
Other comprehensive income (loss)	18			18		0
Common dividends	(125)		(125)
Balance at Mar. 31, 2013	$ 3,631	$ 562	$ 3,048	$ (6)	$ 27	$ 0