Income Taxes Income Taxes - MidAmerican Funding - Components of Net Deferred Income Tax Liability (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities		$ 1,674	$ 1,707
AROs		232	223
Other		459	450
Total deferred income tax assets, net		2,892	3,417
Property-related items		(10,185)	(9,950)
Regulatory assets		(656)	(651)
Other		(222)	(215)
Total deferred income tax liabilities		(11,939)	(11,659)
Net deferred income tax liability		(9,047)	(8,242)
Federal, state and foreign carryforwards		596	1,118
MidAmerican Funding, LLC and Subsidiaries [Domain]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities		405	443
AROs		164	160
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits		47	45
Other		85	62
Total deferred income tax assets, net		701	710
Property-related items		(2,947)	(2,868)
Regulatory assets		(62)	(42)
Other		(11)	(35)
Total deferred income tax liabilities		(3,020)	(2,945)
Net deferred income tax liability		(2,319)	$ (2,235)
State and Local Jurisdiction [Member]
Deferred Tax Assets and Liabilities [Line Items]
Operating Loss Carryforwards	[1]	5,577
State and Local Jurisdiction [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain]
Deferred Tax Assets and Liabilities [Line Items]
Federal, state and foreign carryforwards		44
Operating Loss Carryforwards		$ 655
Minimum [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain]
Deferred Tax Assets and Liabilities [Line Items]
Deferred Tax Assets, Operating Loss and Tax Credit Carry Forwards, Domestic Federal and State, ExpirationDate		2019
Maximum [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain]
Deferred Tax Assets and Liabilities [Line Items]
Deferred Tax Assets, Operating Loss and Tax Credit Carry Forwards, Domestic Federal and State, ExpirationDate		2037

[1] The federal net operating loss carryforwards relate principally to net operating loss carryforwards of subsidiaries that are tax residents in both the United States and the United Kingdom. The federal net operating loss carryforwards were generated prior to Berkshire Hathaway Inc.'s ownership and will begin to expire in 2023.