Employee Benefit Plans (MEC) Asset Allocations (Details) (MidAmerican Energy Company and Subsidiaries [Member])	12 Months Ended
	Dec. 31, 2012
United States Pension Plans of US Entity, Defined Benefit [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	20.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	30.00%
United States Pension Plans of US Entity, Defined Benefit [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	65.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	75.00%
United States Pension Plans of US Entity, Defined Benefit [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	2.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	8.00%
United States Pension Plans of US Entity, Defined Benefit [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	0.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	5.00%
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	25.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	35.00%
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	60.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	80.00%
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	0.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	0.00%
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	0.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	5.00%