Statements of Changes in Shareholder's Equity - MEC - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income, Net [Member]	MidAmerican Energy Company [Member]	MidAmerican Energy Company [Member] Common Stock [Member]	MidAmerican Energy Company [Member] Additional Paid-in Capital [Member]	MidAmerican Energy Company [Member] Retained Earnings [Member]
Stockholders' Equity Attributable to Parent at Dec. 31, 2016						$ 5,160	$ 0	$ 561	$ 4,599
Net Income (Loss) Attributable to Parent	$ 2,198					624			624
Other comprehensive income (loss)	1,088	$ 0	$ 0	$ 0	$ 1,088
Stockholders' Equity, Other	(24)	0	(21)	0	0
Stockholders' Equity Attributable to Parent at Sep. 30, 2017						5,784	0	561	5,223
Stockholders' Equity Attributable to Parent at Dec. 31, 2017	28,176					5,764	0	561	5,203
Net Income (Loss) Attributable to Parent	2,286					695			695
Other comprehensive income (loss)	(184)	$ 0	0	$ 0	$ (184)
Stockholders' Equity, Other	(5)		$ (5)
Stockholders' Equity Attributable to Parent at Sep. 30, 2018	$ 29,557					$ 6,459	$ 0	$ 561	$ 5,898