Employee Benefit Plans - PacifiCorp - Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	$ 666	$ 662
Defined Benefit Plan, Plan Assets, Contributions by Employer	5	2
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	10	10
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	106	41
Defined Benefit Plan, Plan Assets, Payment for Settlement	0	0
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(51)	(49)
Ending balance	736	666	$ 662
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	734	740
Defined Benefit Plan, Service Cost	9	9	11
Defined Benefit Plan, Interest Cost	29	31	31
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	10	10
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(10)	(7)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(51)	(49)
Defined Benefit Plan, Benefit Obligation	734	740	740	$ 721	$ 734
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan				15	(68)
Assets for Plan Benefits, Defined Benefit Plan				32	19
Other current liabilities				0	0
Liability, Defined Benefit Plan, Noncurrent				(17)	(87)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position				15	(68)
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount				272	242
PacifiCorp [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	302	305
Defined Benefit Plan, Plan Assets, Contributions by Employer	1	1
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	7	6
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	49	17
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(27)	(27)
Ending balance	332	302	305
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	358	362
Defined Benefit Plan, Service Cost	2	2	3
Defined Benefit Plan, Interest Cost	14	15	16
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	7	6
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(23)	0
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(27)	(27)
Defined Benefit Plan, Benefit Obligation	358	362	362	331	358
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan				1	(56)
Assets for Plan Benefits, Defined Benefit Plan				1	0
Other current liabilities				0	0
Liability, Defined Benefit Plan, Noncurrent				0	(56)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position				1	(56)
PacifiCorp [Member] | Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount				60	55
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	2,525	2,489
Defined Benefit Plan, Plan Assets, Contributions by Employer	64	78
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	390	163
Defined Benefit Plan, Plan Assets, Payment for Settlement	(15)	(11)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(203)	(194)
Ending balance	2,761	2,525	2,489
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	2,952	2,934
Defined Benefit Plan, Service Cost	24	29	33
Defined Benefit Plan, Interest Cost	116	126	121
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	132	67
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(203)	(194)
Defined Benefit Plan, Benefit Obligation	2,952	2,934	2,934	3,006	2,952
Defined Benefit Plan, Accumulated Benefit Obligation				2,988	2,929
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan				(245)	(427)
Assets for Plan Benefits, Defined Benefit Plan				66	26
Other current liabilities				(14)	(15)
Liability, Defined Benefit Plan, Noncurrent				(297)	(438)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position				(245)	(427)
Domestic Plan [Member] | PacifiCorp [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	999	1,043
Defined Benefit Plan, Plan Assets, Contributions by Employer	54	5
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	166	51
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(108)	(100)
Ending balance	1,111	999	1,043
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	1,276	1,289
Defined Benefit Plan, Service Cost	0	4	4
Defined Benefit Plan, Interest Cost	49	54	53
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	34	29
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(108)	(100)
Defined Benefit Plan, Benefit Obligation	$ 1,276	$ 1,289	$ 1,289	1,251	1,276
Defined Benefit Plan, Accumulated Benefit Obligation				1,251	1,276
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan				(140)	(277)
Assets for Plan Benefits, Defined Benefit Plan				5	0
Other current liabilities				(4)	(5)
Liability, Defined Benefit Plan, Noncurrent				(141)	(272)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position				$ (140)	$ (277)