Employee Benefit Plans - MidAmerican Funding - Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Plan [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 3	$ 4	$ 4
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(21)	(16)	(13)
Other Postretirement Benefits Plan [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (2)	$ (3)	$ (1)