Employee Benefit Plans - MEC - Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	$ 8	$ 0
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	736	666
Defined Benefit Plan, Plan Assets, Contributions by Employer	8	5
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	8	10
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	(38)	106
Defined Benefit Plan, Plan Assets, Payment for Settlement	0	0
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(50)	(51)
Ending balance	664	736	$ 666
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	721	734
Defined Benefit Plan, Service Cost	9	9	9
Defined Benefit Plan, Interest Cost	24	29	31
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	8	10
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(40)	(10)
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	0	0
Defined Benefit Plan, Benefit Obligation, Payment for Settlement	0	0
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(50)	(51)
Ending balance	672	721	734
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(8)	15
Assets for Plan Benefits, Defined Benefit Plan	5	32
Other current liabilities	0	0
Liability, Defined Benefit Plan, Noncurrent	(13)	(17)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(8)	15
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount	256	272
MidAmerican Energy Company [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount	191	198
MidAmerican Energy Company [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	745
Ending balance	644	745
MidAmerican Energy Company [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	277	252
Defined Benefit Plan, Plan Assets, Contributions by Employer	1	1
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	1	1
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	(17)	36
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(15)	(13)
Ending balance	247	277	252
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	246	233
Defined Benefit Plan, Service Cost	5	5	5
Defined Benefit Plan, Interest Cost	8	9	10
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	1	1
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(3)	11
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(15)	(13)
Ending balance	242	246	233
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan	5	31
Assets for Plan Benefits, Defined Benefit Plan	5	31
Other current liabilities	0	0
Liability, Defined Benefit Plan, Noncurrent	0	0
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	5	31
MidAmerican Energy Company [Member] | MidAmerican Energy Company [Member] | Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount	116	118
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	2,761	2,525
Defined Benefit Plan, Plan Assets, Contributions by Employer	38	64
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	(147)	390
Defined Benefit Plan, Plan Assets, Payment for Settlement	(119)	(15)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(137)	(203)
Ending balance	2,396	2,761	2,525
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	3,006	2,952
Defined Benefit Plan, Service Cost	21	24	29
Defined Benefit Plan, Interest Cost	105	116	126
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(160)	132
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	2	0
Defined Benefit Plan, Benefit Obligation, Payment for Settlement	119	15
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(137)	(203)
Ending balance	2,718	3,006	2,952
Defined Benefit Plan, Accumulated Benefit Obligation	2,709	2,988
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(322)	(245)
Assets for Plan Benefits, Defined Benefit Plan	20	66
Other current liabilities	(13)	(14)
Liability, Defined Benefit Plan, Noncurrent	(329)	(297)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(322)	(245)
Domestic Plan [Member] | MidAmerican Energy Company [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	745	684
Defined Benefit Plan, Plan Assets, Contributions by Employer	7	7
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	(39)	114
Defined Benefit Plan, Plan Assets, Payment for Settlement	(37)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(32)	(60)
Ending balance	644	745	684
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	799	773
Defined Benefit Plan, Service Cost	9	9	10
Defined Benefit Plan, Interest Cost	28	31	34
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(33)	46
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	2
Defined Benefit Plan, Benefit Obligation, Payment for Settlement	(37)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(32)	(60)
Ending balance	736	799	$ 773
Defined Benefit Plan, Accumulated Benefit Obligation	733	790
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(92)	(54)
Assets for Plan Benefits, Defined Benefit Plan	17	66
Other current liabilities	(7)	(8)
Liability, Defined Benefit Plan, Noncurrent	(102)	(112)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(92)	(54)
Domestic Plan [Member] | MidAmerican Energy Company [Member] | Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	120
Ending balance	109	120
Defined Benefit Plan, Accumulated Benefit Obligation	$ 109	$ 118