Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2018

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs [Table Text Block]

Net periodic benefit cost for the plans included the following components for the years ended December 31 (in millions):

	Pension									Other Postretirement
	2018			2017			2016			2018			2017			2016
Service cost	$	21		$	24		$	29		$	9		$	9		$	9
Interest cost	105			116			126			24			29			31
Expected return on plan assets	(164		)	(160		)	(160		)	(41		)	(40		)	(41		)
Settlement	21			—			—			—			—			—
Net amortization	28			25			46			(13		)	(14		)	(12		)
Net periodic benefit cost (credit)	$	11		$	5		$	41		$	(21	)	$	(16	)	$	(13	)

Net periodic benefit cost for the UK Plan included the following components for the years ended December 31 (in millions):

	2018			2017			2016
Service cost	$	19		$	23		$	20
Interest cost	56			58			72
Expected return on plan assets	(101		)	(100		)	(110		)
Settlement	44			31			—
Net amortization	45			63			44
Net periodic benefit cost	$	63		$	75		$	26

Changes in Fair Value of Plan Assets [Table Text Block]

The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions):

	Pension						Other Postretirement
	2018			2017			2018			2017
Plan assets at fair value, beginning of year	$	2,761		$	2,525		$	736		$	666
Employer contributions	38			64			8			5
Participant contributions	—			—			8			10
Actual return on plan assets	(147		)	390			(38		)	106
Settlement	(119		)	(15		)	—			—
Benefits paid	(137		)	(203		)	(50		)	(51		)
Plan assets at fair value, end of year	$	2,396		$	2,761		$	664		$	736

The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions):

	2018			2017
Plan assets at fair value, beginning of year	$	2,368		$	2,169
Employer contributions	60			58
Participant contributions	1			1
Actual return on plan assets	(44		)	145
Settlement	(205		)	(144		)
Benefits paid	(71		)	(68		)
Foreign currency exchange rate changes	(120		)	207
Plan assets at fair value, end of year	$	1,989		$	2,368

Changes in Projected Benefit Obligations [Table Text Block]

following table is a reconciliation of the benefit obligation for the years ended December 31 (in millions):

	2018			2017
Benefit obligation, beginning of year	$	2,201		$	2,125
Service cost	19			23
Interest cost	56			58
Participant contributions	1			1
Actuarial gain	(87		)	(4		)
Settlement	(182		)	(131		)
Amendment	8			—
Benefits paid	(71		)	(68		)
Foreign currency exchange rate changes	(112		)	197
Benefit obligation, end of year	$	1,833		$	2,201
Accumulated benefit obligation, end of year	$	1,637		$	1,933

The following table is a reconciliation of the benefit obligations for the years ended December 31 (in millions):

	Pension						Other Postretirement
	2018			2017			2018			2017
Benefit obligation, beginning of year	$	3,006		$	2,952		$	721		$	734
Service cost	21			24			9			9
Interest cost	105			116			24			29
Participant contributions	—			—			8			10
Actuarial (gain) loss	(160		)	132			(40		)	(10		)
Amendment	2			—			—			—
Settlement	(119		)	(15		)	—			—
Benefits paid	(137		)	(203		)	(50		)	(51		)
Benefit obligation, end of year	$	2,718		$	3,006		$	672		$	721
Accumulated benefit obligation, end of year	$	2,709		$	2,988

Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]

The fair value of plan assets, projected benefit obligation and accumulated benefit obligation for (1) pension and other postretirement benefit plans with a projected benefit obligation in excess of the fair value of plan assets and (2) pension plans with an accumulated benefit obligation in excess of the fair value of plan assets as of December 31 are as follows (in millions):

	Pension				Other Postretirement
	2018		2017		2018		2017
Fair value of plan assets	$	1,752	$	2,016	$	417	$	126
Projected benefit obligation	$	2,091	$	2,327	$	429	$	143
Accumulated benefit obligation	$	2,085	$	2,316

The funded status of the UK Plan and the amounts recognized on the Consolidated Balance Sheets as of December 31 are as follows (in millions):

	2018		2017
Plan assets at fair value, end of year	$	1,989	$	2,368
Benefit obligation, end of year	1,833		2,201
Funded status	$	156	$	167
Amounts recognized on the Consolidated Balance Sheets:
Other assets	$	156	$	167

The funded status of the plans and the amounts recognized on the Consolidated Balance Sheets as of December 31 are as follows (in millions):

	Pension						Other Postretirement
	2018			2017			2018			2017
Plan assets at fair value, end of year	$	2,396		$	2,761		$	664		$	736
Benefit obligation, end of year	2,718			3,006			672			721
Funded status	$	(322	)	$	(245	)	$	(8	)	$	15
Amounts recognized on the Consolidated Balance Sheets:
Other assets	$	20		$	66		$	5		$	32
Other current liabilities	(13		)	(14		)	—			—
Other long-term liabilities	(329		)	(297		)	(13		)	(17		)
Amounts recognized	$	(322	)	$	(245	)	$	(8	)	$	15

Net Periodic Benefit Costs Not Yet Recognized [Table Text Block]

A reconciliation of the amounts not yet recognized as components of net periodic benefit cost, which are included in accumulated other comprehensive loss on the Consolidated Balance Sheets, for the years ended December 31 is as follows (in millions):

	2018			2017
Balance, beginning of year	$	510		$	590
Net (gain) loss arising during the year	59			(50		)
Net prior service cost arising during the year	8			—
Settlement	(22		)	(17		)
Net amortization	(45		)	(63		)
Foreign currency exchange rate changes	(30		)	50
Total	(30		)	(80		)
Balance, end of year	$	480		$	510

The portion of the funded status of the plans not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions):

	Pension						Other Postretirement
	2018			2017			2018			2017
Net loss	$	747		$	649		$	50		$	14
Prior service credit	—			(3		)	(22		)	(37		)
Regulatory deferrals	(1		)	(4		)	7			7
Total	$	746		$	642		$	35		$	(16	)

A reconciliation of the amounts not yet recognized as components of net periodic benefit cost for the years ended December 31, 2018 and 2017 is as follows (in millions):

							Accumulated
							Other
	Regulatory			Regulatory			Comprehensive
	Asset			Liability			Loss			Total
Pension
Balance, December 31, 2016	$	761		$	(13	)	$	13		$	761
Net (gain) loss arising during the year	(68		)	(29		)	3			(94		)
Net amortization	(28		)	(1		)	4			(25		)
Total	(96		)	(30		)	7			(119		)
Balance, December 31, 2017	665			(43		)	20			642
Net loss (gain) arising during the year	114			43			(6		)	151
Net prior service cost arising during the year	—			—			2			2
Settlement	(21		)	—			—			(21		)
Net amortization	(28		)	—			—			(28		)
Total	65			43			(4		)	104
Balance, December 31, 2018	$	730		$	—		$	16		$	746

							Accumulated
							Other
	Regulatory			Regulatory			Comprehensive
	Asset			Liability			Loss		Total
Other Postretirement
Balance, December 31, 2016	$	55		$	(12	)	$	—	$	43
Net gain arising during the year	(52		)	(21		)	—		(73		)
Net amortization	7			7			—		14
Total	(45		)	(14		)	—		(59		)
Balance, December 31, 2017	10			(26		)	—		(16		)
Net gain arising during the year	23			14			1		38
Net amortization	11			2			—		13
Total	34			16			1		51
Balance, December 31, 2018	$	44		$	(10	)	$	1	$	35

The portion of the funded status of the UK Plan not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions):

	2018		2017
Net loss	$	472	$	510
Prior service cost	8		—
Total	$	480	$	510

Defined Benefit Plans, Amounts To Be Recognized In Following Year [Table Text Block]

Plan Assumptions [Table Text Block]

Assumptions used to determine benefit obligations and net periodic benefit cost were as follows:

	2018		2017		2016
Benefit obligations as of December 31:
Discount rate	2.90	%	2.60	%	2.70	%
Rate of compensation increase	3.55	%	3.45	%	3.00	%
Rate of future price inflation	3.05	%	2.95	%	3.00	%
Net periodic benefit cost for the years ended December 31:
Discount rate	2.60	%	2.70	%	3.70	%
Expected return on plan assets	4.90	%	5.00	%	5.60	%
Rate of compensation increase	3.45	%	3.00	%	2.90	%
Rate of future price inflation	2.95	%	3.00	%	2.90	%

Weighted-average assumptions used to determine benefit obligations and net periodic benefit cost were as follows:

	Pension						Other Postretirement
	2018		2017		2016		2018		2017		2016
Benefit obligations as of December 31:
Discount rate	4.25	%	3.60	%	4.06	%	4.21	%	3.57	%	4.01	%
Rate of compensation increase	2.75	%	2.75	%	2.75	%	NA		NA		NA
Interest crediting rates for cash balance plan
2016	NA		NA		2.57	%	NA		NA		NA
2017	NA		2.49	%	2.57	%	NA		NA		NA
2018	3.38	%	3.06	%	2.57	%	NA		NA		NA
2019	3.54	%	3.06	%	3.01	%	NA		NA		NA
2020	3.54	%	2.72	%	3.01	%	NA		NA		NA
2021	3.56	%	2.72	%	3.01	%	NA		NA		NA
Net periodic benefit cost for the years ended December 31:
Discount rate	3.60	%	4.06	%	4.43	%	3.57	%	4.01	%	4.33	%
Expected return on plan assets	6.36	%	6.55	%	6.78	%	6.44	%	6.73	%	7.03	%
Rate of compensation increase	2.75	%	2.75	%	2.75	%	NA		NA		NA
Interest crediting rate for cash balance plan	3.38	%	2.49	%	2.57	%	NA		NA		NA

In establishing its assumption as to the expected return on plan assets, the Company utilizes the asset allocation and return assumptions for each asset class based on historical performance and forward-looking views of the financial markets.

	2018		2017
Assumed healthcare cost trend rates as of December 31:
Healthcare cost trend rate assumed for next year	6.80	%	7.10	%
Rate that the cost trend rate gradually declines to	5.00	%	5.00	%
Year that the rate reaches the rate it is assumed to remain at	2025		2025

Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block]

Expected Benefit Payments [Table Text Block]

Employer contributions to the UK Plan are expected to be £43 million during 2019. The expected benefit payments to participants in the UK Plan for 2019 through 2023 and for the five years thereafter excluding lump sum settlement elections, using the foreign currency exchange rate as of December 31, 2018, are summarized below (in millions):

2019	$	70
2020	71
2021	73
2022	75
2023	77
2024-2028	416

The expected benefit payments to participants in the Company's pension and other postretirement benefit plans for 2019 through 2023 and for the five years thereafter are summarized below (in millions):

	Projected Benefit
	Payments
			Other
	Pension		Postretirement
2019	$	221	$	53
2020	224		57
2021	221		55
2022	212		54
2023	212		53
2024-2028	958		243

Allocation of Plan Assets [Table Text Block]

The target allocations (percentage of plan assets) for the UK Plan assets are as follows as of December 31, 2018:

	%
Debt securities(1)	50-55
Equity securities(1)	35-40
Real estate funds and other	5-15

(1) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds have been allocated based on the underlying investments in debt and equity securities.

The target allocations (percentage of plan assets) for the Company's pension and other postretirement benefit plan assets are as follows as of December 31, 2018:

		Other
	Pension	Postretirement
	%	%
PacifiCorp:
Debt securities(1)	30-43	33-37
Equity securities(1)	48-65	62-66
Limited partnership interests	6-12	1-3
MidAmerican Energy:
Debt securities(1)	20-50	25-45
Equity securities(1)	60-80	45-80
Real estate funds	2-8	—
Other	0-3	0-5
NV Energy:
Debt securities(1)	53-77	40
Equity securities(1)	23-47	60

(1) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities.

Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

The following table presents the fair value of the UK Plan assets, by major category (in millions):

	Input Levels for Fair Value Measurements(1)
	Level 1		Level 2		Level 3		Total
As of December 31, 2018:
Cash equivalents	$	3	$	59	$	—	$	62
Debt securities:
United Kingdom government obligations	891		—		—		891
Equity securities:
Investment funds(2)	—		697		—		697
Real estate funds	—		—		239		239
Total	$	894	$	756	$	239	1,889
Investment funds(2) measured at net asset value							100
Total assets measured at fair value							$	1,989
As of December 31, 2017:
Cash equivalents	$	4	$	30	$	—	$	34
Debt securities:
United Kingdom government obligations	870		—		—		870
Equity securities:
Investment funds(2)	—		1,027		—		1,027
Real estate funds	—		—		230		230
Total	$	874	$	1,057	$	230	2,161
Investment funds(2) measured at net asset value							207
Total assets measured at fair value							$	2,368

(1) Refer to Note 14 for additional discussion regarding the three levels of the fair value hierarchy.

(2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 36% and 64%, respectively, for 2018 and 21% and 79%, respectively, for 2017.

The following table presents the fair value of plan assets, by major category, for the Company's defined benefit pension plans (in millions):

	Input Levels for Fair Value Measurements(1)
	Level 1		Level 2		Total
As of December 31, 2018:
Cash equivalents	$	8	$	41	$	49
Debt securities:
United States government obligations	160		—		160
International government obligations	—		5		5
Corporate obligations	—		373		373
Municipal obligations	—		29		29
Agency, asset and mortgage-backed obligations	—		123		123
Equity securities:
United States companies	492		1		493
International companies	108		—		108
Investment funds(2)	119		—		119
Total assets in the fair value hierarchy	$	887	$	572	1,459
Investment funds(2) measured at net asset value					792
Limited partnership interests(3) measured at net asset value					104
Real estate funds measured at net asset value					41
Total assets measured at fair value					$	2,396
As of December 31, 2017:
Cash equivalents	$	10	$	76	$	86
Debt securities:
United States government obligations	218		—		218
Corporate obligations	—		350		350
Municipal obligations	—		16		16
Agency, asset and mortgage-backed obligations	—		110		110
Equity securities:
United States companies	622		—		622
International companies	136		—		136
Investment funds(2)	83		20		103
Total assets in the fair value hierarchy	$	1,069	$	572	1,641
Investment funds(2) measured at net asset value					1,019
Limited partnership interests(3) measured at net asset value					63
Real estate funds measured at net asset value					38
Total assets measured at fair value					$	2,761

(1) Refer to Note 14 for additional discussion regarding the three levels of the fair value hierarchy.

(2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 59% and 41%, respectively, for 2018 and 62% and 38%, respectively, for 2017. Additionally, these funds are invested in United States and international securities of approximately 73% and 27%, respectively, for 2018 and 68% and 32%, respectively, for 2017.

(3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital.

The following table presents the fair value of plan assets, by major category, for the Company's defined benefit other postretirement plans (in millions):

	Input Levels for Fair Value Measurements(1)
	Level 1		Level 2		Total
As of December 31, 2018:
Cash equivalents	$	10	$	2	$	12
Debt securities:
United States government obligations	13		—		13
Corporate obligations	—		42		42
Municipal obligations	—		45		45
Agency, asset and mortgage-backed obligations	—		30		30
Equity securities:
United States companies	158		—		158
International companies	6		—		6
Investment funds	202		1		203
Total assets in the fair value hierarchy	$	389	$	120	509
Investment funds measured at net asset value					149
Limited partnership interests measured at net asset value					6
Total assets measured at fair value					$	664
As of December 31, 2017:
Cash equivalents	$	11	$	3	$	14
Debt securities:
United States government obligations	20		—		20
Corporate obligations	—		36		36
Municipal obligations	—		46		46
Agency, asset and mortgage-backed obligations	—		29		29
Equity securities:
United States companies	185		—		185
International companies	8		—		8
Investment funds(2)	219		1		220
Total assets in the fair value hierarchy	$	443	$	115	558
Investment funds(2) measured at net asset value					174
Limited partnership interests(3) measured at net asset value					4
Total assets measured at fair value					$	736

(1) Refer to Note 14 for additional discussion regarding the three levels of the fair value hierarchy.

(2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 65% and 35%, respectively, for 2018 and 68% and 32%, respectively, for 2017. Additionally, these funds are invested in United States and international securities of approximately 79% and 21%, respectively, for 2018 and 73% and 27%, respectively, for 2017.

(3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital.

The following table presents the Company's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions):

	Input Levels for Fair Value Measurements
	Level 1			Level 2			Level 3			Other(1)			Total
As of December 31, 2018:
Assets:
Commodity derivatives	$	1		$	91		$	108		$	(52	)	$	148
Interest rate derivatives	1			13			10			—			24
Mortgage loans held for sale	—			468			—			—			468
Money market mutual funds(2)	409			—			—			—			409
Debt securities:
United States government obligations	187			—			—			—			187
International government obligations	—			4			—			—			4
Corporate obligations	—			46			—			—			46
Municipal obligations	—			2			—			—			2
Agency, asset and mortgage-backed obligations	—			1			—			—			1
Equity securities:
United States companies	256			—			—			—			256
International companies	1,441			—			—			—			1,441
Investment funds	128			—			—			—			128
	$	2,423		$	625		$	118		$	(52	)	$	3,114
Liabilities:
Commodity derivatives	$	(1	)	$	(180	)	$	(9	)	$	111		$	(79	)
Interest rate derivatives	—			(32		)	—			—			(32		)
	$	(1	)	$	(212	)	$	(9	)	$	111		$	(111	)

As of December 31, 2017:
Assets:
Commodity derivatives	$	1		$	42		$	104		$	(29	)	$	118
Interest rate derivatives	—			15			9			—			24
Mortgage loans held for sale	—			465			—			—			465
Money market mutual funds(2)	685			—			—			—			685
Debt securities:
United States government obligations	176			—			—			—			176
International government obligations	—			5			—			—			5
Corporate obligations	—			36			—			—			36
Municipal obligations	—			2			—			—			2
Equity securities:
United States companies	288			—			—			—			288
International companies	1,968			—			—			—			1,968
Investment funds	178			—			—			—			178
	$	3,296		$	565		$	113		$	(29	)	$	3,945
Liabilities:
Commodity derivatives	$	(3	)	$	(167	)	$	(10	)	$	105		$	(75	)
Interest rate derivatives	—			(8		)	—			—			(8		)
	$	(3	)	$	(175	)	$	(10	)	$	105		$	(83	)

(1) Represents netting under master netting arrangements and a net cash collateral receivable of $59 million and $76 million as of December 31, 2018 and 2017, respectively.

(2) Amounts are included in cash and cash equivalents; other current assets; and noncurrent investments and restricted cash and investments on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.

Level Three Defined Benefit Plan Assets Roll Forward [Table Text Block]

The following table reconciles the beginning and ending balances of the UK Plan assets measured at fair valueusing significant Level 3 inputs for the years ended December 31 (in millions):

	Real Estate Funds
	2018			2017		2016
Beginning balance	$	230		$	105	$	204
Actual return on plan assets still held at period end	23			6		10
Purchases (sales)	—			104		(80		)
Foreign currency exchange rate changes	(14		)	15		(29		)
Ending balance	$	239		$	230	$	105

PacifiCorp [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs [Table Text Block]

Net periodic benefit cost for the plans included the following components for the years ended December 31 (in millions):

	Pension									Other Postretirement
	2018			2017			2016			2018			2017			2016
Service cost	$	—		$	—		$	4		$	2		$	2		$	2
Interest cost	43			49			54			11			14			15
Expected return on plan assets	(72		)	(72		)	(75		)	(21		)	(21		)	(21		)
Settlement	22			—			—			—			—			—
Net amortization	13			14			34			(6		)	(6		)	(5		)
Net periodic benefit cost (credit)	$	6		$	(9	)	$	17		$	(14	)	$	(11	)	$	(9	)

Changes in Fair Value of Plan Assets [Table Text Block]

The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions):

	Pension						Other Postretirement
	2018			2017			2018			2017
Plan assets at fair value, beginning of year	$	1,111		$	999		$	332		$	302
Employer contributions	4			54			1			1
Participant contributions	—			—			5			7
Actual return on plan assets	(52		)	166			(16		)	49
Settlement	(52		)	—			—			—
Benefits paid	(69		)	(108		)	(25		)	(27		)
Plan assets at fair value, end of year	$	942		$	1,111		$	297		$	332

Changes in Projected Benefit Obligations [Table Text Block]

The following table is a reconciliation of the benefit obligations for the years ended December 31 (in millions):

	Pension						Other Postretirement
	2018			2017			2018			2017
Benefit obligation, beginning of year	$	1,251		$	1,276		$	331		$	358
Service cost	—			—			2			2
Interest cost	43			49			11			14
Participant contributions	—			—			5			7
Actuarial (gain) loss	(68		)	34			(26		)	(23		)
Settlement	(52		)	—						—
Benefits paid	(69		)	(108		)	(25		)	(27		)
Benefit obligation, end of year	$	1,105		$	1,251		$	298		$	331
Accumulated benefit obligation, end of year	$	1,105		$	1,251

Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]

The funded status of the plans and the amounts recognized on the Consolidated Balance Sheets as of December 31 are as follows (in millions):

	Pension						Other Postretirement
	2018			2017			2018			2017
Plan assets at fair value, end of year	$	942		$	1,111		$	297		$	332
Less - Benefit obligation, end of year	1,105			1,251			298			331
Funded status	$	(163	)	$	(140	)	$	(1	)	$	1
Amounts recognized on the Consolidated Balance Sheets:
Other assets	$	3		$	5		$	—		$	1
Other current liabilities	(4		)	(4		)	—			—
Other long-term liabilities	(162		)	(141		)	(1		)	—
Amounts recognized	$	(163	)	$	(140	)	$	(1	)	$	1

Net Periodic Benefit Costs Not Yet Recognized [Table Text Block]

The portion of the funded status of the plans not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions):

	Pension						Other Postretirement
	2018			2017			2018			2017
Net loss (gain)	$	461		$	442		$	(2	)	$	(12	)
Prior service credit	—			—			—			(6		)
Regulatory deferrals	(1		)	(4		)	7			7
Total	$	460		$	438		$	5		$	(11	)

A reconciliation of the amounts not yet recognized as components of net periodic benefit cost for the years ended December 31, 2018 and 2017 is as follows (in millions):

				Accumulated
				Other
	Regulatory			Comprehensive
	Asset			Loss			Total
Pension
Balance, December 31, 2016	$	491		$	20		$	511
Net (gain) loss arising during the year	(60		)	1			(59		)
Net amortization	(13		)	(1		)	(14		)
Total	(73		)	—			(73		)
Balance, December 31, 2017	418			20			438
Net loss (gain) arising during the year	59			(2		)	57
Net amortization	(12		)	(1		)	(13		)
Settlement	(22		)	—			(22		)
Total	25			(3		)	22
Balance, December 31, 2018	$	443		$	17		$	460

	Regulatory
	Asset (Liability)
Other Postretirement
Balance, December 31, 2016	$	34
Net gain arising during the year	(51		)
Net amortization	6
Total	(45		)
Balance, December 31, 2017	(11		)
Net loss arising during the year	10
Net amortization	6
Total	16
Balance, December 31, 2018	$	5

Defined Benefit Plans, Amounts To Be Recognized In Following Year [Table Text Block]

Plan Assumptions [Table Text Block]

ssumptions used to determine benefit obligations and net periodic benefit cost were as follows:

	Pension						Other Postretirement
	2018		2017		2016		2018		2017		2016
Benefit obligations as of December 31:
Discount rate	4.25	%	3.60	%	4.05	%	4.25	%	3.60	%	4.05	%
Rate of compensation increase	N/A		N/A		N/A		N/A		N/A		N/A
Interest crediting rates for cash balance plan (1)(2)(3)	3.40	%	1.61	%	2.06	%	N/A		N/A		N/A
Net periodic benefit cost for the years ended December 31:
Discount rate	3.60	%	4.05	%	4.40	%	3.60	%	4.05	%	4.35	%
Expected return on plan assets	7.00		7.25		7.50		6.86		7.25		7.50
Rate of compensation increase	N/A		N/A		2.75		N/A		N/A		N/A

(1) 2018 Cash Balance Interest Crediting Rate assumption is 3.40% for 2019 and all future years for nonunion participants and 3.15% for 2019-2020 and 3.25% for 2021+ for union participants.

(2) 2017 Cash Balance Interest Crediting Rate assumption was 2.26% for 2018-2019 and 1.60% for 2020+ for nonunion participants and 2.78% for 2018-2019 and 2.60% for 2020+ for union participants.

(3) 2016 Cash Balance Interest Crediting Rate assumption was 1.44% for 2017-2018 and 2.05% for 2019+ for nonunion participants and 2.35% for 2017-2018 and 3.05% for 2019+ for union participants.

In establishing its assumption as to the expected return on plan assets, PacifiCorp utilizes the asset allocation and return assumptions for each asset class based on historical performance and forward-looking views of the financial markets.

As a result of a plan amendment effective on January 1, 2017, the benefit obligation for the Retirement Plan is no longer affected by future increases in compensation. As a result of a labor settlement reached with UMWA in December 2014, the benefit obligation for the other postretirement plan is no longer affected by healthcare cost trends.

Expected Benefit Payments [Table Text Block]

The expected benefit payments to participants in PacifiCorp's pension and other postretirement benefit plans for 2019 through 2023 and for the five years thereafter are summarized below (in millions):

	Projected Benefit Payments
	Pension		Other Postretirement
2019	$	105	$	24
2020	102		26
2021	98		23
2022	92		22
2023	88		21
2024-2028	369		95

Allocation of Plan Assets [Table Text Block]

The target allocations (percentage of plan assets) for PacifiCorp's pension and other postretirement benefit plan assets are as follows as of December 31, 2018:

	Pension(1)	Other Postretirement(1)
	%	%
Debt securities(2)	30 - 43	33 - 37
Equity securities(2)	48 - 65	62 - 66
Limited partnership interests	6 - 12	1 - 3

(1) PacifiCorp's Retirement Plan trust includes a separate account that is used to fund benefits for the other postretirement benefit plan. In addition to this separate account, the assets for the other postretirement benefit plan are held in Voluntary Employees' Beneficiary Association ("VEBA") trusts, each of which has its own investment allocation strategies. Target allocations for the other postretirement benefit plan include the separate account of the Retirement Plan trust and the VEBA trusts.

(2) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities.

Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

The following table presents the fair value of plan assets, by major category, for PacifiCorp's defined benefit pension plan (in millions):

	Input Levels for Fair Value Measurements
	Level 1(1)		Level 2(1)		Level 3(1)		Total
As of December 31, 2018:
Cash equivalents	$	—	$	11	$	—	$	11
Debt securities:
United States government obligations	4		—		—		4
International government obligations	—		1		—		1
Corporate obligations	—		88		—		88
Municipal obligations	—		10		—		10
Agency, asset and mortgage-backed obligations	—		43		—		43
Equity securities:
United States companies	327		—		—		327
International companies	15		—		—		15
Investment funds(2)	54		—		—		54
Total assets in the fair value hierarchy	$	400	$	153	$	—	553
Investment funds(2) measured at net asset value							285
Limited partnership interests(3) measured at net asset value							104
Investments at fair value							$	942
As of December 31, 2017:
Cash equivalents	$	—	$	43	$	—	$	43
Debt securities:
United States government obligations	45		—		—		45
Corporate obligations	—		60		—		60
Municipal obligations	—		9		—		9
Agency, asset and mortgage-backed obligations	—		37		—		37
Equity securities:
United States companies	416		—		—		416
International companies	22		—		—		22
Total assets in the fair value hierarchy	$	483	$	149	$	—	632
Investment funds(2) measured at net asset value							416
Limited partnership interests(3) measured at net asset value							63
Investments at fair value							$	1,111

(1) Refer to Note 12 for additional discussion regarding the three levels of the fair value hierarchy.

(2) Investment funds are substantially comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately55% and 45% respectively, for 2018 and 60% and 40%, respectively, for 2017, and are invested in United States and international securities of approximately 68% and 32%, respectively, for 2018 and 57% and 43%, respectively, for 2017.

(3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital.

The following table presents the fair value of plan assets, by major category, for PacifiCorp's defined benefit other postretirement plan (in millions):

	Input Levels for Fair Value Measurements
	Level 1(1)		Level 2(1)		Level 3(1)		Total
As of December 31, 2018:
Cash and cash equivalents	$	4	$	1	$	—	$	5
Debt securities:
United States government obligations	3		—		—		3
Corporate obligations	—		23		—		23
Municipal obligations	—		2		—		2
Agency, asset and mortgage-backed obligations	—		17		—		17
Equity securities:
United States companies	83		—		—		83
International companies	4		—		—		4
Investment funds(2)	38		—		—		38
Total assets in the fair value hierarchy	132		43		—		175
Investment funds(2) measured at net asset value							116
Limited partnership interests(3) measured at net asset value							6
Investments at fair value							$	297
As of December 31, 2017:
Cash and cash equivalents	$	4	$	3	$	—	$	7
Debt securities:
United States government obligations	11		—		—		11
Corporate obligations	—		16		—		16
Municipal obligations	—		2		—		2
Agency, asset and mortgage-backed obligations	—		16		—		16
Equity securities:
United States companies	98		—		—		98
International companies	6		—		—		6
Investment funds(2)	32		—		—		32
Total assets in the fair value hierarchy	151		37		—		188
Investment funds(2) measured at net asset value							140
Limited partnership interests(3) measured at net asset value							4
Investments at fair value							$	332

(1) Refer to Note 12 for additional discussion regarding the three levels of the fair value hierarchy.

(2) Investment funds are substantially comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately59% and 41%, respectively, for 2018 and 63% and 37%, respectively, for 2017, and are invested in United States and international securities of approximately 90% and 10%, respectively, for 2018 and 77% and 23%, respectively, for 2017.

(3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital.

The following table presents PacifiCorp's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions):

	Input Levels for Fair Value Measurements
	Level 1		Level 2			Level 3		Other(1)			Total
As of December 31, 2018:
Assets:
Commodity derivatives	$	—	$	51		$	—	$	(23	)	$	28
Money market mutual funds(2)	69		—			—		—			69
Investment funds	24		—			—		—			24
	$	93	$	51		$	—	$	(23	)	$	121
Liabilities - Commodity derivatives	$	—	$	(148	)	$	—	$	82		$	(66	)
As of December 31, 2017:
Assets:
Commodity derivatives	$	—	$	13		$	—	$	(4	)	$	9
Money market mutual funds (2)	21		—			—		—			21
Investment funds	21		—			—		—			21
	$	42	$	13		$	—	$	(4	)	$	51
Liabilities - Commodity derivatives	$	—	$	(117	)	$	—	$	78		$	(39	)

(1) Represents netting under master netting arrangements and a net cash collateral receivable of $59 million and $74 million as of December 31, 2018 and 2017, respectively.

(2) Amounts are included in cash and cash equivalents, other current assets and other assets on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.

Schedule of Multiemployer Plans [Table Text Block]

The following table presents PacifiCorp's participation in individually significant joint trustee and multiemployer pension plans for the years ended December 31 (dollars in millions):

		PPA zone status or
		plan funded status percentage for
		plan years beginning July 1,					Contributions(1)
Plan name	Employer Identification Number	2018	2017	2016	Funding improvement plan	Surcharge imposed under PPA(1)	2018		2017		2016		Year contributions to plan exceeded more than 5% of total contributions(2)
Local 57 Trust Fund	87-0640888	At least 80%	At least 80%	At least 80%	None	None	$	7	$	7	$	8	2016, 2015, 2014

(1) PacifiCorp's minimum contributions to the plan are based on the amount of wages paid to employees covered by the Local 57 Trust Fund collective bargaining agreements, subject to ERISA minimum funding requirements.

(2) For the Local 57 Trust Fund, information is for plan years beginning July 1, 2016, 2015 and 2014. Information for the plan year beginning July 1, 2017 is not yet available.

MidAmerican Energy Company [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs [Table Text Block]

Net periodic benefit cost for the plans of MidAmerican Energy and the aforementioned affiliates included the following components for the years ended December 31 (in millions):

	Pension									Other Postretirement
	2018			2017			2016			2018			2017			2016
Service cost	$	9		$	9		$	10		$	5		$	5		$	5
Interest cost	28			31			34			8			9			10
Expected return on plan assets	(44		)	(44		)	(44		)	(13		)	(14		)	(13		)
Settlement	(1		)	—			—			—			—			—
Net amortization	2			2			2			(4		)	(4		)	(4		)
Net periodic benefit (credit) cost	$	(6	)	$	(2	)	$	2		$	(4	)	$	(4	)	$	(2	)

Changes in Fair Value of Plan Assets [Table Text Block]

The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions):

	Pension						Other Postretirement
	2018			2017			2018			2017
Plan assets at fair value, beginning of year	$	745		$	684		$	277		$	252
Employer contributions	7			7			1			1
Participant contributions	—			—			1			1
Actual return on plan assets	(39		)	114			(17		)	36
Settlement	(37		)	—			—			—
Benefits paid	(32		)	(60		)	(15		)	(13		)
Plan assets at fair value, end of year	$	644		$	745		$	247		$	277

Changes in Projected Benefit Obligations [Table Text Block]

The following table is a reconciliation of the benefit obligations for the years ended December 31 (in millions):

	Pension						Other Postretirement
	2018			2017			2018			2017
Benefit obligation, beginning of year	$	799		$	773		$	246		$	233
Service cost	9			9			5			5
Interest cost	28			31			8			9
Participant contributions	—			—			1			1
Actuarial (gain) loss	(33		)	46			(3		)	11
Plan amendments	2			—			—			—
Settlement	(37		)	—			—			—
Benefits paid	(32		)	(60		)	(15		)	(13		)
Benefit obligation, end of year	$	736		$	799		$	242		$	246
Accumulated benefit obligation, end of year	$	733		$	790

Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]

The funded status of the plans and the amounts recognized on the Balance Sheets as of December 31 are as follows (in millions):

	Pension						Other Postretirement
	2018			2017			2018		2017
Plan assets at fair value, end of year	$	644		$	745		$	247	$	277
Less - Benefit obligation, end of year	736			799			242		246
Funded status	$	(92	)	$	(54	)	$	5	$	31
Amounts recognized on the Balance Sheets:
Other assets	$	17		$	66		$	5	$	31
Other current liabilities	(7		)	(8		)	—		—
Other liabilities	(102		)	(112		)	—		—
Amounts recognized	$	(92	)	$	(54	)	$	5	$	31

Net Periodic Benefit Costs Not Yet Recognized [Table Text Block]

The portion of the funded status of the plans not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions):

	Pension					Other Postretirement
	2018		2017			2018			2017
Net loss (gain)	$	40	$	(11	)	$	48		$	23
Prior service cost (credit)	1		1			(20		)	(25		)
Total	$	41	$	(10	)	$	28		$	(2	)

A reconciliation of the amounts not yet recognized as components of net periodic benefit cost for the years ended December 31, 2018 and 2017 is as follows (in millions):

	Regulatory Asset			Regulatory Liability			Receivables (Payables) with Affiliates		Total
Pension
Balance, December 31, 2016	$	22		$	(12	)	$	6	$	16
Net loss (gain) arising during the year	4			(29		)	1		(24		)
Net amortization	(2		)	—			—		(2		)
Total	2			(29		)	1		(26		)
Balance, December 31, 2017	24			(41		)	7		(10		)
Net loss arising during the year	2			41			9		52
Net amortization	(2		)	—			—		(2		)
Settlement	1			—			—		1
Total	1			41			9		51
Balance, December 31, 2018	$	25		$	—		$	16	$	41

	Regulatory Asset			Receivables (Payables) with Affiliates			Total
Other Postretirement
Balance, December 31, 2016	$	18		$	(13	)	$	5
Net gain arising during the year	(7		)	(4		)	(11		)
Net amortization	3			1			4
Total	(4		)	(3		)	(7		)
Balance, December 31, 2017	14			(16		)	(2		)
Net loss arising during the year	20			6			26
Net amortization	3			1			4
Total	23			7			30
Balance, December 31, 2018	$	37		$	(9	)	$	28

Plan Assumptions [Table Text Block]

Assumptions used to determine benefit obligations and net periodic benefit cost were as follows:

	Pension						Other Postretirement
	2018		2017		2016		2018		2017		2016
Benefit obligations as of December 31:
Discount rate	4.25	%	3.60	%	4.10	%	4.15	%	3.50	%	3.90	%
Rate of compensation increase	2.75	%	2.75	%	2.75	%	N/A		N/A		N/A
Interest crediting rates for cash balance plan
2016	N/A		N/A		1.18	%	N/A		N/A		N/A
2017	N/A		1.44	%	1.44	%	N/A		N/A		N/A
2018	2.26	%	2.26	%	1.44	%	N/A		N/A		N/A
2019	3.40	%	2.26	%	2.10	%	N/A		N/A		N/A
2020	3.40	%	1.60	%	2.10	%	N/A		N/A		N/A
2021 and beyond	3.40	%	1.60	%	2.10	%	N/A		N/A		N/A
Net periodic benefit cost for the years ended December 31:
Discount rate	3.60	%	4.10	%	4.50	%	3.50	%	3.90	%	4.25	%
Expected return on plan assets(1)	6.50	%	6.75	%	7.00	%	6.25	%	6.50	%	6.75	%
Rate of compensation increase	2.75	%	2.75	%	2.75	%	N/A		N/A		N/A
Interest crediting rates for cash balance plan	2.26	%	1.44	%	1.18	%	N/A		N/A		N/A

(1) Amounts reflected are pre-tax values. Assumed after-tax returns for a taxable, non-union other postretirement plan were 4.13% for 2018, and 4.81% for 2017, and 5.00% for 2016.

In establishing its assumption as to the expected return on plan assets, MidAmerican Energy utilizes the asset allocation and return assumptions for each asset class based on historical performance and forward-looking views of the financial markets.

	2018		2017
Assumed healthcare cost trend rates as of December 31:
Healthcare cost trend rate assumed for next year	6.80	%	7.10	%
Rate that the cost trend rate gradually declines to	5.00	%	5.00	%
Year that the rate reaches the rate it is assumed to remain at	2025		2025

Expected Benefit Payments [Table Text Block]

Net periodic benefit costs assigned to MidAmerican Energy affiliates are reimbursed currently in accordance with its intercompany administrative services agreement. The expected benefit payments to participants in MidAmerican Energy's pension and other postretirement benefit plans for 2019 through 2023 and for the five years thereafter are summarized below (in millions):

	Projected Benefit Payments
	Pension		Other Postretirement
2019	$	61	$	19
2020	62		21
2021	61		22
2022	60		22
2023	58		22
2024-2028	262		102

Allocation of Plan Assets [Table Text Block]

The target allocations (percentage of plan assets) for MidAmerican Energy's pension and other postretirement benefit plan assets are as follows as of December 31, 2018:

	Pension	Other Postretirement
	%	%
Debt securities(1)	20-50	25-45
Equity securities(1)	60-80	45-80
Real estate funds	2-8	—
Other	0-3	0-5

(1) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities.

Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

The following table presents the fair value of plan assets, by major category, for MidAmerican Energy's defined benefit pension plan (in millions):

	Input Levels for Fair Value Measurements(1)
	Level 1		Level 2		Level 3		Total
As of December 31, 2018:
Cash equivalents	$	—	$	20	$	—	$	20
Debt securities:
United States government obligations	6		—		—		6
Corporate obligations	—		63		—		63
Municipal obligations	—		6		—		6
Agency, asset and mortgage-backed obligations	—		37		—		37
Equity securities:
United States companies	111		—		—		111
International companies	35		—		—		35
Investment funds(2)	65		—		—		65
Total assets in the hierarchy	$	217	$	126	$	—	—
Investment funds(2) measured at net asset value							260
Real estate funds measured at net asset value							41
Total assets measured at fair value							$	644
As of December 31, 2017:
Cash equivalents	$	—	$	17	$	—	$	17
Debt securities:
United States government obligations	21		—		—		21
Corporate obligations	—		59		—		59
Municipal obligations	—		7		—		7
Agency, asset and mortgage-backed obligations	—		33		—		33
Equity securities:
United States companies	137		—		—		137
International companies	44		—		—		44
Investment funds(2)	74		—		—		74
Total assets in the hierarchy	$	276	$	116	$	—	392
Investment funds(2) measured at net asset value							315
Real estate funds measured at net asset value							38
Total assets measured at fair value							$	745

(1) Refer to Note 12 for additional discussion regarding the three levels of the fair value hierarchy.

(2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 65% and 35%, respectively, for 2018 and 69% and 31%, respectively, for 2017. Additionally, these funds are invested in United States and international securities of approximately 74% and 26%, respectively, for 2018 and 72% and 28%, respectively, for 2017.

The following table presents the fair value of plan assets, by major category, for MidAmerican Energy's defined benefit other postretirement plans (in millions):

	Input Levels for Fair Value Measurements(1)
	Level 1		Level 2		Level 3		Total
As of December 31, 2018:
Cash equivalents	$	5	$	—	$	—	$	5
Debt securities:
United States government obligations	6		—		—		6
Corporate obligations	—		12		—		12
Municipal obligations	—		43		—		43
Agency, asset and mortgage-backed obligations	—		12		—		12
Equity securities:
United States companies	73		—		—		73
Investment funds(2)	96		—		—		96
Total assets measured at fair value	$	180	$	67	$	—	$	247
As of December 31, 2017:
Cash equivalents	$	6	$	—	$	—	$	6
Debt securities:
United States government obligations	5		—		—		5
Corporate obligations	—		14		—		14
Municipal obligations	—		44		—		44
Agency, asset and mortgage-backed obligations	—		12		—		12
Equity securities:
United States companies	84		—		—		84
Investment funds(2)	112		—		—		112
Total assets measured at fair value	$	207	$	70	$	—	$	277

(1) Refer to Note 12 for additional discussion regarding the three levels of the fair value hierarchy.

(2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 78% and 22%, respectively, for 2018 and 81% and 19%, respectively, for 2017. Additionally, these funds are invested in United States and international securities of approximately 41% and 59%, respectively, for 2018 and 42% and 58%, respectively, for 2017.

The following table presents MidAmerican Energy's assets and liabilities recognized on the Balance Sheets and measured at fair value on a recurring basis (in millions):

	Input Levels for Fair Value Measurements
	Level 1		Level 2			Level 3			Other(1)			Total
As of December 31, 2018:
Assets:
Commodity derivatives	$	—	$	4		$	2		$	(3	)	$	3
Money market mutual funds(2)	2		—			—			—			2
Debt securities:
United States government obligations	187		—			—			—			187
International government obligations	—		4			—			—			4
Corporate obligations	—		46			—			—			46
Municipal obligations	—		2			—			—			2
Agency, asset and mortgage-backed obligations	—		1			—			—			1
Equity securities:
United States companies	256		—			—			—			256
International companies	6		—			—			—			6
Investment funds	10		—			—			—			10
	$	461	$	57		$	2		$	(3	)	$	517
Liabilities:
Commodity derivatives	$	—	$	(4	)	$	(2	)	$	3		$	(3	)
Interest rate derivatives(3)	—		(19		)	—			—			(19		)
	$	—	$	(23	)	$	(2	)	$	3		$	(22	)
As of December 31, 2017
Assets:
Commodity derivatives	$	—	$	3		$	4		$	(2	)	$	5
Money market mutual funds(2)	133		—			—			—			133
Debt securities:
United States government obligations	176		—			—			—			176
International government obligations	—		5			—			—			5
Corporate obligations	—		36			—			—			36
Municipal obligations	—		2			—			—			2
Equity securities:
United States companies	288		—			—			—			288
International companies	7		—			—			—			7
Investment funds	15		—			—			—			15
	$	619	$	46		$	4		$	(2	)	$	667
Liabilities - commodity derivatives	$	—	$	(9	)	$	(1	)	$	2		$	(8	)

(1) Represents netting under master netting arrangements and a net cash collateral receivable of $- million as of December 31, 2018 and 2017.

(2) Amounts are included in cash and cash equivalents and investments and restricted cash and investments on the Balance Sheets. The fair value of these money market mutual funds approximates cost.

MidAmerican Funding, LLC and Subsidiaries [Domain]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs [Table Text Block]

Pension and postretirement costs allocated by MidAmerican Funding to its parent and other affiliates in each of the years ended December 31, were as follows (in millions):

	2018			2017			2016
Pension costs	$	3		$	4		$	4
Other postretirement costs	(2		)	(3		)	(1		)