Income Taxes - MidAmerican Funding - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Components of Income Tax Expense (Benefit) [Line Items]
Current Federal Tax Expense (Benefit)	$ (956)	$ (686)	$ (653)
Current State and Local Tax Expense (Benefit)	(13)	(9)	(3)
Current Income Tax Expense (Benefit)	(888)	(591)	(573)
Deferred Federal Income Tax Expense (Benefit)	431	165	(76)
Deferred State and Local Income Tax Expense (Benefit)	(127)	(131)	100
Deferred Income Tax Expense (Benefit)	296	14	26
Other Tax Expense (Benefit)	(6)	(6)	(7)
Income tax (benefit) expense	(598)	(583)	(554)
MidAmerican Funding, LLC and Subsidiaries [Domain]
Components of Income Tax Expense (Benefit) [Line Items]
Current Federal Tax Expense (Benefit)	(480)	(280)	(505)
Current State and Local Tax Expense (Benefit)	(49)	(14)	(31)
Current Income Tax Expense (Benefit)	(529)	(294)	(536)
Deferred Federal Income Tax Expense (Benefit)	164	42	338
Deferred State and Local Income Tax Expense (Benefit)	(11)	(9)	(3)
Deferred Income Tax Expense (Benefit)	153	33	335
Other Tax Expense (Benefit)	(1)	(1)	(1)
Income tax (benefit) expense	$ (377)	$ (262)	$ (202)