Employee Benefit Plans - MEC - Contributions and Benefit Payments (Details) $ in Millions	Dec. 31, 2018 USD ($)
Pension Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 7
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	61
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	62
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	61
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	60
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	58
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	262
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	1
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	53
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	57
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	55
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	54
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	53
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	243
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	1
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	19
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	21
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	22
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	22
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	22
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	$ 102