Commitments and Contingencies (MEC) (Details) (MidAmerican Energy Company and Subsidiaries [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Contractual Obligation [Line Items]
Contractual Obligation, Due in Next Twelve Months	$ 540
Contractual Obligation, Due in Second Year	308
Contractual Obligation, Due in Third Year	198
Contractual Obligation, Due in Fourth Year	141
Contractual Obligation, Due in Fifth Year	83
Contractual Obligation, Due after Fifth Year	499
Contractual Obligation	1,769
Rent expense	32	25	21
Guarantees of residual value specified in operating leases	22
Coal and natural gas for generation [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	206
Purchase Obligation, Due in Second Year	123
Purchase Obligation, Due in Third Year	89
Purchase Obligation, Due in Fourth Year	50
Purchase Obligation, Due in Fifth Year	9
Purchase Obligation, Due after Fifth Year	0
Purchase Obligation	477
Electric capacity and transmission [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	34
Purchase Obligation, Due in Second Year	29
Purchase Obligation, Due in Third Year	29
Purchase Obligation, Due in Fourth Year	26
Purchase Obligation, Due in Fifth Year	26
Purchase Obligation, Due after Fifth Year	99
Purchase Obligation	243
Natural gas contracts for gas operations [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	131
Purchase Obligation, Due in Second Year	75
Purchase Obligation, Due in Third Year	56
Purchase Obligation, Due in Fourth Year	46
Purchase Obligation, Due in Fifth Year	37
Purchase Obligation, Due after Fifth Year	23
Purchase Obligation	368
Construction commitments [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	135
Purchase Obligation, Due in Second Year	52
Purchase Obligation, Due in Third Year	0
Purchase Obligation, Due in Fourth Year	0
Purchase Obligation, Due in Fifth Year	0
Purchase Obligation, Due after Fifth Year	0
Purchase Obligation	187
Operating leases, easements and maintenance and services contracts [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	34
Purchase Obligation, Due in Second Year	29
Purchase Obligation, Due in Third Year	24
Purchase Obligation, Due in Fourth Year	19
Purchase Obligation, Due in Fifth Year	11
Purchase Obligation, Due after Fifth Year	377
Purchase Obligation	$ 494