Statements of Changes in Equity (MEC) - MidAmerican Energy Company [Member] - USD ($) $ in Millions	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), Net [Member]
Balance at Dec. 31, 2013	$ 3,845	$ 561	$ 3,295	$ (11)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	189		189
Other comprehensive income (loss)	24			24
Balance at Jun. 30, 2014	4,058	561	3,484	13
Balance at Dec. 31, 2014	4,250	561	3,712	(23)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	225		225
Other comprehensive income (loss)	(3)			(3)
Balance at Jun. 30, 2015	$ 4,472	$ 561	$ 3,937	$ (26)