Employee Benefit Plans - MEC - Contributions and Benefit Payments (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)
United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	$ 34
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	221
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	224
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	226
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	224
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	225
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	1,054
Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	1
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	56
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	57
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	58
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	58
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	61
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	272
MidAmerican Energy Company [Member] | United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	8
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	59
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	60
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	60
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	60
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	61
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	291
MidAmerican Energy Company [Member] | Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	1
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	17
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	19
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	20
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	21
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	21
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	$ 102