Income Taxes - MEC - Components of Net Deferred Income Tax Liability (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	$ 1,610	$ 1,674
AROs	306	232
Other	590	527
Total deferred income tax assets, net	2,938	2,892
Property-related items	(10,439)	(10,185)
Regulatory assets	(631)	(656)
Other	(384)	(222)
Total deferred income tax liabilities	(12,591)	(11,939)
Net deferred income tax liability	(9,653)	(9,047)
MidAmerican Energy Company [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	368	405
AROs	234	164
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits	26	47
Other	71	80
Total deferred income tax assets, net	699	696
Property-related items	(3,253)	(2,945)
Regulatory assets	(68)	(61)
Other	(4)	(12)
Total deferred income tax liabilities	(3,325)	(3,018)
Net deferred income tax liability	$ (2,626)	$ (2,322)