Employee Benefit Plans - MEC - Contributions and Benefit Payments (Details) $ in Millions	Dec. 31, 2020 USD ($)
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 13
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	236
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	219
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	220
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	211
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	206
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	926
Pension Plan [Member] | MidAmerican Energy Company [Member] | UNITED STATES
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	64
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	62
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	60
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	58
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	56
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	248
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	53
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	54
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	54
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	54
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	52
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	238
Other Postretirement Benefits Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	14
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	12
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	20
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	23
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	22
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	$ 104