Employee Benefit Plans (MEC) Contributions and Benefit Payments (Details) (MidAmerican Energy Company and Subsidiaries [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2012
United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	$ 8
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	53
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	56
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	56
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	310
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	0
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	15
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	15
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	16
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	17
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	18
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	$ 92