Employee Benefit Plans (MEC) Funded Status (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
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount	$ 168	$ 156
United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Fair Value of Plan Assets	555	546
Employer contributions	65	55
Participant contributions	0	0
Actual return on plan assets	74	0
Benefits paid	(51)	(46)
Defined Benefit Plan, Fair Value of Plan Assets	643	555	546
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year	799	738
Service cost	18	18	17
Interest cost	37	39	39
Participant contributions	0	0
Plan amendments	0	0
Actuarial loss (gain)	43	50
Benefits paid	(51)	(46)
Benefit obligation, end of year	846	799	738
Accumulated benefit obligation, end of year	821	771
Defined Benefit Plan, Funded Status of Plan [Abstract]
Defined Benefit Plan, Fair Value of Plan Assets	643	555	546
Less - Benefit obligation, end of year	846	799	738
Funded status	(203)	(244)
Other assets	0	0
Other current liabilities	(8)	(8)
Other liabilities	(195)	(236)
Amounts recognized	(203)	(244)
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Fair Value of Plan Assets	213	216
Employer contributions	1	2
Participant contributions	2	7
Actual return on plan assets	25	4
Benefits paid	(15)	(16)
Defined Benefit Plan, Fair Value of Plan Assets	226	213	216
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year	198	189
Service cost	4	4	4
Interest cost	8	10	11
Participant contributions	2	7
Plan amendments	0	(18)
Actuarial loss (gain)	16	22
Benefits paid	(15)	(16)
Benefit obligation, end of year	213	198	189
Defined Benefit Plan, Funded Status of Plan [Abstract]
Defined Benefit Plan, Fair Value of Plan Assets	226	213	216
Less - Benefit obligation, end of year	213	198	189
Funded status	13	15
Other assets	13	15
Other current liabilities	0	0
Other liabilities	0	0
Amounts recognized	13	15
Supplemental Employee Retirement Plans, Defined Benefit [Member] | MEHC [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount	136	129
Supplemental Employee Retirement Plans, Defined Benefit [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount	$ 94	$ 92