Income Taxes - MidAmerican Funding - Net Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 185	$ 181
Additions based on tax positions related to the current year	3	4
Additions for tax positions of prior years	13	38
Reductions for tax positions of prior years	(37)	(38)
Statute of limitations	(9)	(2)
Settlements	(5)	(2)
Interest and penalties	(5)	0
Ending balance	145	185
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	139	154
MidAmerican Funding, LLC and Subsidiaries [Domain]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	10	12
Additions based on tax positions related to the current year	5	4
Additions for tax positions of prior years	10	47
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions	(5)	(4)
Reductions for tax positions of prior years	(12)	(48)
Interest and penalties	0	(1)
Ending balance	8	$ 10
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 27