Consolidated Statements of Changes in Equity (MEC) (MidAmerican Energy Company and Subsidiaries [Member], USD $) In Millions, unless otherwise specified	MidAmerican Energy Company and Subsidiaries [Member] USD ($)	MidAmerican Energy Company and Subsidiaries [Member] Common Stock [Member] USD ($)	MidAmerican Energy Company and Subsidiaries [Member] Retained Earnings [Member] USD ($)	MidAmerican Energy Company and Subsidiaries [Member] Accumulated Other Comprehensive Loss, Net [Member] USD ($)	MidAmerican Energy Company and Subsidiaries [Member] Preferred Securities [Member] USD ($)	MidAmerican Energy Company and Subsidiaries [Member] Noncontrolling Interests [Member] USD ($)
Balance at Dec. 31, 2010	$ 2,959	$ 562	$ 2,398	$ (29)	$ 27	$ 1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	123		123			0
Other comprehensive income (loss)	13			13		0
Preferred dividends	(1)		(1)
Balance at Jun. 30, 2011	3,094	562	2,520	(16)	27	1
Balance at Mar. 31, 2011
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	49
Other comprehensive income (loss)	10
Balance at Jun. 30, 2011	3,094	562			27
Balance at Dec. 31, 2011	3,272	562	2,716	(34)	27	1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	155		155			0
Other comprehensive income (loss)	(7)			(7)		0
Preferred dividends	(1)		(1)
Balance at Jun. 30, 2012	3,419	562	2,870	(41)	27	1
Balance at Mar. 31, 2012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	81
Other comprehensive income (loss)	7
Balance at Jun. 30, 2012	$ 3,419	$ 562			$ 27