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

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, 2016:
Assets:
Commodity derivatives	$	5		$	49		$	87		$	(22	)	$	119
Interest rate derivatives	—			16			7			—			23
Mortgage loans held for sale	—			359			—			—			359
Money market mutual funds⁽²⁾	586			—			—			—			586
Debt securities:
United States government obligations	161			—			—			—			161
International government obligations	—			3			—			—			3
Corporate obligations	—			36			—			—			36
Municipal obligations	—			2			—			—			2
Agency, asset and mortgage-backed obligations	—			2			—			—			2
Equity securities:
United States companies	250			—			—			—			250
International companies	1,190			—			—			—			1,190
Investment funds	147			—			—			—			147
	$	2,339		$	467		$	94		$	(22	)	$	2,878
Liabilities:
Commodity derivatives	$	(2	)	$	(199	)	$	(27	)	$	96		$	(132	)
Interest rate derivatives	(1		)	(11		)	(1		)	—			(13		)
	$	(3	)	$	(210	)	$	(28	)	$	96		$	(145	)



As of December 31, 2015:
Assets:
Commodity derivatives	$	—		$	16		$	93		$	(16	)	$	93
Interest rate derivatives	—			5			5			—			10
Mortgage loans held for sale	—			327			—			—			327
Money market mutual funds⁽²⁾	421			—			—			—			421
Debt securities:
United States government obligations	133			—			—			—			133
International government obligations	—			2			—			—			2
Corporate obligations	—			39			—			—			39
Municipal obligations	—			1			—			—			1
Agency, asset and mortgage-backed obligations	—			3			—			—			3
Auction rate securities	—			—			44			—			44
Equity securities:
United States companies	239			—			—			—			239
International companies	1,244			—			—			—			1,244
Investment funds	136			—			—			—			136
	$	2,173		$	393		$	142		$	(16	)	$	2,692
Liabilities:
Commodity derivatives	$	(13	)	$	(283	)	$	(46	)	$	119		$	(223	)
Interest rate derivatives	—			(13		)	(1		)	—			(14		)
	$	(13	)	$	(296	)	$	(47	)	$	119		$	(237	)


(1)	Represents netting under master netting arrangements and a net cash collateral receivable of $74 million and $103 million as of December 31, 2016 and 2015, 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.

United States Pension Plan of US Entity [Member]

Changes in Fair Value of Plan Assets [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
	2016			2015			2014			2016			2015			2014

Service cost	$	29		$	33		$	36		$	9		$	11		$	14
Interest cost	126			121			131			31			31			46
Expected return on plan assets	(160		)	(169		)	(164		)	(41		)	(45		)	(53		)
Net amortization	46			53			44			(12		)	(11		)	(3		)
Net periodic benefit cost (credit)	$	41		$	38		$	47		$	(13	)	$	(14	)	$	4

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



	Pension						Other Postretirement
	2016			2015			2016			2015

Plan assets at fair value, beginning of year	$	2,489		$	2,718		$	662		$	858
Employer contributions	78			13			2			2
Participant contributions	—			—			10			9
Actual return on plan assets	163			(17		)	41			—
Settlement	(11		)	(23		)	—			(150		)
Benefits paid	(194		)	(202		)	(49		)	(57		)
Plan assets at fair value, end of year	$	2,525		$	2,489		$	666		$	662

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
	2016			2015			2016			2015

Benefit obligation, beginning of year	$	2,934		$	3,119		$	740		$	936
Service cost	29			33			9			11
Interest cost	126			121			31			31
Participant contributions	—			—			10			9
Actuarial loss (gain)	67			(110		)	(7		)	(43		)
Amendment	1			(4		)	—			3
Settlement	(11		)	(23		)	—			(150		)
Benefits paid	(194		)	(202		)	(49		)	(57		)
Benefit obligation, end of year	$	2,952		$	2,934		$	734		$	740
Accumulated benefit obligation, end of year	$	2,929		$	2,906

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
	2016		2015		2016		2015

Fair value of plan assets	$	1,841	$	1,811	$	413	$	413

Projected benefit obligation	$	2,294	$	2,263	$	500	$	505

Accumulated benefit obligation	$	2,278	$	2,244

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
	2016			2015			2016			2015

Plan assets at fair value, end of year	$	2,525		$	2,489		$	666		$	662
Benefit obligation, end of year	2,952			2,934			734			740
Funded status	$	(427	)	$	(445	)	$	(68	)	$	(78	)

Amounts recognized on the Consolidated Balance Sheets:
Other assets	$	26		$	7		$	19		$	15
Other current liabilities	(15		)	(15		)	—			—
Other long-term liabilities	(438		)	(437		)	(87		)	(93		)
Amounts recognized	$	(427	)	$	(445	)	$	(68	)	$	(78	)

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 for the years ended December 31, 2016 and 2015 is as follows (in millions):



							Accumulated
							Other
	Regulatory			Regulatory			Comprehensive
	Asset			Liability			Loss			Total
Pension
Balance, December 31, 2014	$	710		$	(6	)	$	19		$	723
Net loss (gain) arising during the year	76			5			(6		)	75
Net prior service credit arising during the year	(4		)	—			—			(4		)
Net amortization	(53		)	—			—			(53		)
Total	19			5			(6		)	18
Balance, December 31, 2015	729			(1		)	13			741
Net loss arising during the year	76			(11		)	—			65
Net prior service cost arising during the year	1			—			—			1
Net amortization	(45		)	(1		)	—			(46		)
Total	32			(12		)	—			20
Balance, December 31, 2016	$	761		$	(13	)	$	13		$	761



	Regulatory			Regulatory
	Asset			Liability			Total
Other Postretirement
Balance, December 31, 2014	$	37		$	(14	)	$	23
Net (gain) loss arising during the year	(1		)	1			—
Net prior service cost arising during the year	3			—			3
Net amortization	10			1			11
Total	12			2			14
Balance, December 31, 2015	49			(12		)	37
Net gain arising during the year	(5		)	(1		)	(6		)
Net amortization	11			1			12
Total	6			—			6
Balance, December 31, 2016	$	55		$	(12	)	$	43

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
	2016			2015			2016			2015

Net loss	$	775		$	768		$	88		$	97
Prior service credit	(7		)	(25		)	(52		)	(68		)
Regulatory deferrals	(7		)	(2		)	7			8
Total	$	761		$	741		$	43		$	37

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

The net loss, prior service credit and regulatory deferrals that will be amortized in 2017 into net periodic benefit cost are estimated to be as follows (in millions):



	Net		Prior Service			Regulatory
	Loss		Credit			Deferrals			Total

Pension	$	33	$	(3	)	$	(2	)	$	28
Other postretirement	2		(16		)	1			(13		)
Total	$	35	$	(19	)	$	(1	)	$	15

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

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



	Pension						Other Postretirement
	2016		2015		2014		2016		2015		2014

Benefit obligations as of December 31:
Discount rate	4.06	%	4.43	%	4.00	%	4.01	%	4.33	%	3.88	%
Rate of compensation increase	2.75	%	2.75	%	2.75	%	N/A		N/A		N/A

Net periodic benefit cost for the years ended December 31:
Discount rate	4.43	%	4.00	%	4.81	%	4.33	%	3.93	%	4.82	%
Expected return on plan assets	6.78	%	6.88	%	6.86	%	7.03	%	7.00	%	7.34	%
Rate of compensation increase	2.75	%	2.75	%	3.00	%	N/A		N/A		N/A

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.



	2016		2015
Assumed healthcare cost trend rates as of December 31:
Healthcare cost trend rate assumed for next year	7.40	%	7.70	%
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

A one percentage-point change in assumed healthcare cost trend rates would have the following effects (in millions):



	One Percentage-Point
	Increase		Decrease
Increase (decrease) in:
Total service and interest cost for the year ended December 31, 2016	$	1	$	—
Other postretirement benefit obligation as of December 31, 2016	4		(4		)

The expected benefit payments to participants in the Company's pension and other postretirement benefit plans for 2017 through 2021 and for the five years thereafter are summarized below (in millions):



	Projected Benefit
	Payments
			Other
	Pension		Postretirement

2017	$	219	$	56
2018	226		57
2019	224		57
2020	221		60
2021	214		57
2022-2026	1,002		259

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

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, 2016:



		Other
	Pension	Postretirement
	%	%
PacifiCorp:
Debt securities⁽¹⁾	33-37	33-37
Equity securities⁽¹⁾	53-57	61-65
Limited partnership interests	8-12	1-3
Other	0-1	0-1

MidAmerican Energy:
Debt securities⁽¹⁾	20-40	25-45
Equity securities⁽¹⁾	60-80	50-80
Real estate funds	2-8	—
Other	0-5	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.

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		Level 3		Total
As of December 31, 2016:
Cash equivalents	$	4	$	54	$	—	$	58
Debt securities:
United States government obligations	161		—		—		161
International government obligations	—		2		—		2
Corporate obligations	—		295		—		295
Municipal obligations	—		20		—		20
Agency, asset and mortgage-backed obligations	—		112		—		112
Equity securities:
United States companies	583		—		—		583
International companies	117		—		—		117
Investment funds⁽²⁾	146		—		—		146
Total assets in the fair value hierarchy	$	1,011	$	483	$	—	1,494
Investment funds⁽²⁾ measured at net asset value							920
Limited partnership interests⁽³⁾ measured at net asset value							61
Real estate funds measured at net asset value							50
Total assets measured at fair value							$	2,525

As of December 31, 2015:
Cash equivalents	$	—	$	26	$	—	$	26
Debt securities:
United States government obligations	155		—		—		155
International government obligations	—		4		—		4
Corporate obligations	—		335		—		335
Municipal obligations	—		25		—		25
Agency, asset and mortgage-backed obligations	—		154		—		154
Equity securities:
United States companies	586		—		—		586
International companies	122		—		—		122
Investment funds⁽²⁾	144		—		—		144
Total assets in the fair value hierarchy	$	1,007	$	544	$	—	1,551
Investment funds⁽²⁾ measured at net asset value							823
Limited partnership interests⁽³⁾ measured at net asset value							65
Real estate funds measured at net asset value							50
Total assets measured at fair value							$	2,489


(1)	Refer to Note 15 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 62% and 38%, respectively, for 2016 and 66% and 34%, respectively, for 2015. Additionally, these funds are invested in United States and international securities of approximately 60% and 40%, respectively, for 2016 and 58% and 42%, respectively, for 2015.


(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		Level 3		Total
As of December 31, 2016:
Cash equivalents	$	18	$	2	$	—	$	20
Debt securities:
United States government obligations	19		—		—		19
Corporate obligations	—		29		—		29
Municipal obligations	—		39		—		39
Agency, asset and mortgage-backed obligations	—		25		—		25
Equity securities:
United States companies	217		—		—		217
International companies	5		—		—		5
Investment funds⁽²⁾	152		—		—		152
Total assets in the fair value hierarchy	$	411	$	95	$	—	506
Investment funds⁽²⁾ measured at net asset value							156
Limited partnership interests⁽³⁾ measured at net asset value							4
Total assets measured at fair value							$	666

As of December 31, 2015:
Cash equivalents	$	12	$	1	$	—	$	13
Debt securities:
United States government obligations	18		—		—		18
Corporate obligations	—		33		—		33
Municipal obligations	—		41		—		41
Agency, asset and mortgage-backed obligations	—		28		—		28
Equity securities:
United States companies	216		—		—		216
International companies	6		—		—		6
Investment funds⁽²⁾	149		—		—		149
Total assets in the fair value hierarchy	$	401	$	103	$	—	504
Investment funds⁽²⁾ measured at net asset value							154
Limited partnership interests⁽³⁾ measured at net asset value							4
Total assets measured at fair value							$	662


(1)	Refer to Note 15 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 63% and 37%, respectively, for both 2016 and 2015. Additionally, these funds are invested in United States and international securities of approximately 72% and 28%, respectively, for 2016 and 70% and 30%, respectively, for 2015.


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

UK Pension Plans [Member]

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

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



	2016			2015			2014

Service cost	$	20		$	24		$	24
Interest cost	72			79			95
Expected return on plan assets	(110		)	(116		)	(124		)
Net amortization	44			62			51
Net periodic benefit cost	$	26		$	49		$	46

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



	2016			2015

Plan assets at fair value, beginning of year	$	2,276		$	2,368
Employer contributions	55			77
Participant contributions	1			2
Actual return on plan assets	349			48
Benefits paid	(115		)	(91		)
Foreign currency exchange rate changes	(397		)	(128		)
Plan assets at fair value, end of year	$	2,169		$	2,276

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):



	2016			2015

Benefit obligation, beginning of year	$	2,142		$	2,279
Service cost	20			24
Interest cost	72			79
Participant contributions	1			2
Actuarial loss (gain)	387			(30		)
Benefits paid	(115		)	(91		)
Foreign currency exchange rate changes	(382		)	(121		)
Benefit obligation, end of year	$	2,125		$	2,142
Accumulated benefit obligation, end of year	$	1,858		$	1,891

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

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):



	2016		2015

Plan assets at fair value, end of year	$	2,169	$	2,276
Benefit obligation, end of year	2,125		2,142
Funded status	$	44	$	134

Amounts recognized on the Consolidated Balance Sheets:
Other assets	$	44	$	134

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):



	2016			2015

Balance, beginning of year	$	592		$	655
Net loss arising during the year	148			38
Net amortization	(44		)	(62		)
Foreign currency exchange rate changes	(106		)	(39		)
Total	(2		)	(63		)
Balance, end of year	$	590		$	592

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):



	2016		2015

Net loss	$	590	$	592

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



	2016		2015		2014

Benefit obligations as of December 31:
Discount rate	2.70	%	3.70	%	3.60	%
Rate of compensation increase	3.00	%	2.90	%	2.80	%
Rate of future price inflation	3.00	%	2.90	%	2.80	%

Net periodic benefit cost for the years ended December 31:
Discount rate	3.70	%	3.60	%	4.40	%
Expected return on plan assets	5.60	%	5.60	%	6.10	%
Rate of compensation increase	2.90	%	2.80	%	3.15	%
Rate of future price inflation	2.90	%	2.80	%	3.15	%

Employer contributions to the UK Plan are expected to be £37 million during 2017. The expected benefit payments to participants in the UK Plan for 2017 through 2021 and for the five years thereafter, using the foreign currency exchange rate as of December 31, 2016, are summarized below (in millions):



2017	$	75
2018	77
2019	79
2020	81
2021	83
2022-2026	448

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

The target allocations (percentage of plan assets) for the UK Plan assets are as follows as of December 31, 2016:



	%
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 Company adopted ASU No. 2015-07, "Fair Value Measurement (Topic 820) - Disclosures for Investments in Certain Entities that Calculate Net Asset Value per Share (or its Equivalent)" effective January 1, 2016 under a retrospective method.

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, 2016:
Cash equivalents	$	4	$	83	$	—	$	87
Debt securities:
United Kingdom government obligations	718		—		—		718
Equity securities:
Investment funds⁽²⁾	—		1,095		—		1,095
Real estate funds	—		—		105		105
Total	$	722	$	1,178	$	105	2,005
Investment funds⁽²⁾ measured at net asset value							164
Total assets measured at fair value							$	2,169

As of December 31, 2015:
Cash equivalents	$	46	$	—	$	—	$	46
Debt securities:
United Kingdom government obligations	424		—		—		424
Other international government obligations	—		13		—		13
Corporate obligations	—		186		—		186
Equity securities:
Investment funds⁽²⁾	24		1,189		—		1,213
Real estate funds	—		—		204		204
Total	$	494	$	1,388	$	204	2,086
Investment funds⁽²⁾ measured at net asset value							190
Total assets measured at fair value							$	2,276


(1)	Refer to Note 15 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 44% and 56%, respectively, for both 2016 and 2015.

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 value using significant Level 3 inputs for the years ended December 31 (in millions):



	Real Estate Funds
	2016			2015			2014

Beginning balance	$	204		$	199		$	179
Actual return on plan assets still held at period end	10			18			33
Sales	(80		)	—			—
Foreign currency exchange rate changes	(29		)	(13		)	(13		)
Ending balance	$	105		$	204		$	199

PacifiCorp [Member]

Changes in Fair Value of Plan Assets [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
	2016			2015			2014			2016			2015			2014

Service cost	$	4		$	4		$	5		$	2		$	3		$	6
Interest cost	54			53			57			15			16			28
Expected return on plan assets	(75		)	(77		)	(76		)	(21		)	(23		)	(31		)
Net amortization	34			42			29			(5		)	(4		)	2
Net periodic benefit cost (credit)	$	17		$	22		$	15		$	(9	)	$	(8	)	$	5

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



	Pension						Other Postretirement
	2016			2015			2016			2015

Plan assets at fair value, beginning of year	$	1,043		$	1,146		$	305		$	482
Employer contributions	5			4			1			1
Participant contributions	—			—			6			6
Actual return on plan assets	51			—			17			1
Settlement	—			—			—			(150		)
Benefits paid	(100		)	(107		)	(27		)	(35		)
Plan assets at fair value, end of year	$	999		$	1,043		$	302		$	305

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
	2016			2015			2016			2015

Benefit obligation, beginning of year	$	1,289		$	1,378		$	362		$	539
Service cost	4			4			2			3
Interest cost	54			53			15			16
Participant contributions	—			—			6			6
Actuarial (gain) loss	29			(39		)	—			(17		)
Settlement	—			—			—			(150		)
Benefits paid	(100		)	(107		)	(27		)	(35		)
Benefit obligation, end of year	$	1,276		$	1,289		$	358		$	362
Accumulated benefit obligation, end of year	$	1,276		$	1,289

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
	2016			2015			2016			2015

Plan assets at fair value, end of year	$	999		$	1,043		$	302		$	305
Less - Benefit obligation, end of year	1,276			1,289			358			362
Funded status	$	(277	)	$	(246	)	$	(56	)	$	(57	)

Amounts recognized on the Consolidated Balance Sheets:
Other current liabilities	$	(5	)	$	(4	)	$	—		$	—
Other long-term liabilities	(272		)	(242		)	(56		)	(57		)
Amounts recognized	$	(277	)	$	(246	)	$	(56	)	$	(57	)

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
	2016			2015			2016			2015

Net loss	$	518		$	508		$	39		$	36
Prior service credit	—			(13		)	(13		)	(19		)
Regulatory deferrals	(7		)	(3		)	8			9
Total	$	511		$	492		$	34		$	26

A reconciliation of the amounts not yet recognized as components of net periodic benefit cost for the years ended December 31, 2016 and 2015 is as follows (in millions):



				Accumulated
				Other
	Regulatory			Comprehensive
	Asset			Loss			Total
Pension
Balance, December 31, 2014	$	474		$	22		$	496
Net loss (gain) arising during the year	40			(2		)	38
Net amortization	(41		)	(1		)	(42		)
Total	(1		)	(3		)	(4		)
Balance, December 31, 2015	473			19			492
Net loss arising during the year	51			2			53
Net amortization	(33		)	(1		)	(34		)
Total	18			1			19
Balance, December 31, 2016	$	491		$	20		$	511



	Regulatory
	Asset
Other Postretirement
Balance, December 31, 2014	$	17
Net loss arising during the year	5
Net amortization	4
Total	9
Balance, December 31, 2015	26
Net loss arising during the year	3
Net amortization	5
Total	8
Balance, December 31, 2016	$	34

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

The net loss, prior service credit and regulatory deferrals that will be amortized in 2017 into net periodic benefit cost are estimated to be as follows (in millions):



	Net		Prior Service			Regulatory
	Loss		Credit			Deferrals			Total

Pension	$	16	$	—		$	(2	)	$	14
Other postretirement	—		(7		)	1			(6		)
Total	$	16	$	(7	)	$	(1	)	$	8

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



	Pension						Other Postretirement
	2016		2015		2014		2016		2015		2014

Benefit obligations as of December 31:
Discount rate	4.05	%	4.40	%	4.00	%	4.05	%	4.35	%	3.90	%
Rate of compensation increase	N/A		2.75		2.75		N/A		N/A		N/A

Net periodic benefit cost for the years ended December 31:
Discount rate	4.40	%	4.00	%	4.80	%	4.35	%	3.99	%	4.90	%
Expected return on plan assets	7.50		7.50		7.50		7.50		7.08		7.50
Rate of compensation increase	2.75		2.75		3.00		N/A		N/A		N/A

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 discussed above in "Utah Mine Disposition and Labor Agreement," PacifiCorp remeasured the other postretirement plan assets and benefit obligation as of May 31, 2015. The other postretirement assumptions for the year ended December 31, 2015 presented above reflect a weighted average calculation that considered the assumptions used in the periods preceding and subsequent to the remeasurement.

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 the labor settlement discussed above in "Utah Mine Disposition and Labor Agreement," the benefit obligation for the other postretirement plan is no longer affected by healthcare cost trends.

The expected benefit payments to participants in PacifiCorp's pension and other postretirement benefit plans for 2017 through 2021 and for the five years thereafter are summarized below (in millions):



	Projected Benefit Payments
	Pension		Other Postretirement

2017	$	105	$	28
2018	109		28
2019	108		27
2020	104		30
2021	97		26
2022-2026	426		116

Fair Value, Assets and Liabilities Measured on Recurring Basis [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, 2016:



	Pension⁽¹⁾	Other Postretirement⁽¹⁾
	%	%
Debt securities⁽²⁾	33 - 37	33 - 37
Equity securities⁽²⁾	53 - 57	61 - 65
Limited partnership interests	8 - 12	1 - 3
Other	0 - 1	0 - 1

(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.

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, 2016:
Cash equivalents	$	—	$	10	$	—	$	10
Debt securities:
United States government obligations	25		—		—		25
Corporate obligations	—		36		—		36
Municipal obligations	—		6		—		6
Agency, asset and mortgage-backed obligations	—		37		—		37
Equity securities:
United States companies	389		—		—		389
International companies	15		—		—		15
Investment funds⁽²⁾	83		—		—		83
Total assets in the fair value hierarchy	$	512	$	89	$	—	601
Investment funds⁽²⁾measured at net asset value							337
Limited partnership interests⁽³⁾measured at net asset value							61
Investments at fair value							$	999

As of December 31, 2015:
Cash equivalents	$	—	$	10	$	—	$	10
Debt securities:
United States government obligations	19		—		—		19
Corporate obligations	—		42		—		42
Municipal obligations	—		5		—		5
Agency, asset and mortgage-backed obligations	—		43		—		43
Equity securities:
United States companies	408		—		—		408
International companies	17		—		—		17
Investment funds⁽²⁾	83		—		—		83
Total assets in the fair value hierarchy	$	527	$	100	$	—	627
Investment funds⁽²⁾measured at net asset value							351
Limited partnership interests⁽³⁾measured at net asset value							65
Investments at fair value							$	1,043


(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 approximately 54% and 46% respectively, for 2016 and 53% and 47%, respectively, for 2015, and are invested in United States and international securities of approximately 39% and 61%, respectively, for 2016 and 40% and 60%, respectively, for 2015.


(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, 2016:
Cash and cash equivalents	$	4	$	1	$	—	$	5
Debt securities:
United States government obligations	11		—		—		11
Corporate obligations	—		13		—		13
Municipal obligations	—		2		—		2
Agency, asset and mortgage-backed obligations	—		13		—		13
Equity securities:
United States companies	93		—		—		93
International companies	4		—		—		4
Investment funds⁽²⁾	32		—		—		32
Total assets in the fair value hierarchy	$	144	$	29	$	—	173
Investment funds⁽²⁾measured at net asset value							125
Limited partnership interests⁽³⁾measured at net asset value							4
Investments at fair value							$	302

As of December 31, 2015:
Cash and cash equivalents	$	4	$	1	$	—	$	5
Debt securities:
United States government obligations	9		—		—		9
Corporate obligations	—		15		—		15
Municipal obligations	—		1		—		1
Agency, asset and mortgage-backed obligations	—		14		—		14
Equity securities:
United States companies	95		—		—		95
International companies	4		—		—		4
Investment funds⁽²⁾	32		—		—		32
Total assets in the fair value hierarchy	$	144	$	31	$	—	175
Investment funds⁽²⁾measured at net asset value							126
Limited partnership interests⁽³⁾measured at net asset value							4
Investments at fair value							$	305


(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 approximately 62% and 38%, respectively, for 2016 and 61% and 39%, respectively, for 2015, and are invested in United States and international securities of approximately 71% and 29%, respectively, for 2016 and 67% and 33%, respectively, for 2015.


(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, 2016:
Assets:
Commodity derivatives	$	—	$	27		$	—	$	(7	)	$	20
Money market mutual funds⁽²⁾	13		—			—		—			13
Investment funds	17		—			—		—			17
	$	30	$	27		$	—	$	(7	)	$	50

Liabilities - Commodity derivatives	$	—	$	(104	)	$	—	$	76		$	(28	)

As of December 31, 2015:
Assets:
Commodity derivatives	$	—	$	9		$	3	$	(3	)	$	9
Money market mutual funds ⁽²⁾	13		—			—		—			13
Investment funds	15		—			—		—			15
	$	28	$	9		$	3	$	(3	)	$	37

Liabilities - Commodity derivatives	$	—	$	(148	)	$	—	$	78		$	(70	)


(1)	Represents netting under master netting arrangements and a net cash collateral receivable of $69 million and $75 million as of December 31, 2016 and 2015, 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 and Energy West Mining Company'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	2016	2015	2014	Funding improvement plan	Surcharge imposed under PPA⁽¹⁾	2016		2015		2014		Year contributions to plan exceeded more than 5% of total contributions⁽²⁾
UMWA 1974 Pension Plan	52-1050282	Critical and Declining	Critical and Declining	Critical	Implemented	Yes	$	—	$	1	$	2	None
Local 57 Trust Fund	87-0640888	At least 80%	At least 80%	At least 80%	None	None	$	8	$	8	$	9	2015, 2014, 2013

(1)

PacifiCorp's and Energy West Mining Company's minimum contributions to the plans are based on the amount of wages paid to employees covered by the Local 57 Trust Fund collective bargaining agreements and the number of mining hours worked for the UMWA 1974 Pension Plan, respectively, subject to ERISA minimum funding requirements. As a result of the plan's critical status, Energy West Mining Company was required to begin paying a surcharge for hours worked on and after December 1, 2014.


(2)	For the UMWA 1974 Pension Plan, information is for plan years beginning July 1, 2014, 2013 and 2012. Information for the plan year beginning July 1, 2015 is not yet available. For the Local 57 Trust Fund, information is for plan years beginning July 1, 2014, 2013 and 2012. Information for the plan year beginning July 1, 2015 is not yet available.

MidAmerican Energy Company [Member]

Changes in Fair Value of Plan Assets [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
	2016			2015			2014			2016			2015			2014

Service cost	$	10		$	12		$	14		$	5		$	7		$	6
Interest cost	34			32			35			10			9			10
Expected return on plan assets	(44		)	(46		)	(45		)	(13		)	(15		)	(15		)
Net amortization	2			2			1			(4		)	(3		)	(3		)
Net periodic benefit cost (credit)	$	2		$	—		$	5		$	(2	)	$	(2	)	$	(2	)

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



	Pension						Other Postretirement
	2016			2015			2016			2015

Plan assets at fair value, beginning of year	$	678		$	730		$	249		$	259
Employer contributions	7			7			1			1
Participant contributions	—			—			1			1
Actual return on plan assets	57			4			14			—
Benefits paid	(58		)	(63		)	(13		)	(12		)
Plan assets at fair value, end of year	$	684		$	678		$	252		$	249

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
	2016			2015			2016			2015

Benefit obligation, beginning of year	$	785		$	840		$	234		$	249
Service cost	10			12			5			7
Interest cost	34			32			10			9
Participant contributions	—			—			1			1
Actuarial loss (gain)	2			(36		)	(4		)	(20		)
Benefits paid	(58		)	(63		)	(13		)	(12		)
Benefit obligation, end of year	$	773		$	785		$	233		$	234
Accumulated benefit obligation, end of year	$	764		$	773

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
	2016			2015			2016		2015

Plan assets at fair value, end of year	$	684		$	678		$	252	$	249
Less - Benefit obligation, end of year	773			785			233		234
Funded status	$	(89	)	$	(107	)	$	19	$	15

Amounts recognized on the Balance Sheets:
Other assets	$	26		$	7		$	19	$	15
Other current liabilities	(8		)	(8		)	—		—
Other liabilities	(107		)	(106		)	—		—
Amounts recognized	$	(89	)	$	(107	)	$	19	$	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 for the years ended December 31, 2016 and 2015 is as follows (in millions):



	Regulatory Asset			Regulatory Liability			Receivables (Payables) with Affiliates			Total
Pension
Balance, December 31, 2014	$	22		$	(5	)	$	7		$	24
Net loss (gain) arising during the year	2			5			(1		)	6
Net amortization	(2		)	—			—			(2		)
Total	—			5			(1		)	4
Balance, December 31, 2015	22			—			6			28
Net gain arising during the year	1			(11		)	—			(10		)
Net amortization	(1		)	(1		)	—			(2		)
Total	—			(12		)	—			(12		)
Balance, December 31, 2016	$	22		$	(12	)	$	6		$	16



	Regulatory Asset			Regulatory Liability		Receivables (Payables) with Affiliates			Total
Other Postretirement
Balance, December 31, 2014	$	20		$	—	$	(13	)	$	7
Net gain arising during the year	(5		)	—		—			(5		)
Net amortization	2			—		2			4
Total	(3		)	—		2			(1		)
Balance, December 31, 2015	17			—		(11		)	6
Net gain arising during the year	(2		)	—		(3		)	(5		)
Net amortization	3			—		1			4
Total	1			—		(2		)	(1		)
Balance, December 31, 2016	$	18		$	—	$	(13	)	$	5

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
	2016		2015		2016			2015

Net loss	$	15	$	26	$	36		$	42
Prior service cost (credit)	1		2		(31		)	(36		)
Total	$	16	$	28	$	5		$	6

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

The net loss and prior service cost (credit) that will be amortized in 2017 into net periodic benefit cost are estimated to be as follows (in millions):



	Net Loss		Prior Service Cost (Credit)			Total

Pension	$	1	$	1		$	2
Other postretirement	2		(6		)	(4		)
Total	$	3	$	(5	)	$	(2	)

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

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



	Pension						Other Postretirement
	2016		2015		2014		2016		2015		2014
Benefit obligations as of December 31:
Discount rate	4.10	%	4.50	%	4.00	%	3.90	%	4.25	%	3.75	%
Rate of compensation increase	2.75	%	2.75	%	2.75	%	N/A		N/A		N/A

Net periodic benefit cost for the years ended December 31:
Discount rate	4.50	%	4.00	%	4.75	%	4.25	%	3.75	%	4.50	%
Expected return on plan assets⁽¹⁾	7.00	%	7.25	%	7.50	%	6.75	%	7.00	%	7.25	%
Rate of compensation increase	2.75	%	2.75	%	3.00	%	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 5.00% for 2016, and 5.18% for 2015, and 5.37% for 2014.

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.



	2016		2015
Assumed healthcare cost trend rates as of December 31:
Healthcare cost trend rate assumed for next year	7.40	%	7.70	%
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

A one percentage-point change in assumed healthcare cost trend rates would have the following effects (in millions):



	One Percentage-Point
	Increase		Decrease
Increase (decrease) in:
Total service and interest cost for the year ended December 31, 2016	$	—	$	—
Other postretirement benefit obligation as of December 31, 2016	3		(2		)

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 2017 through 2021 and for the five years thereafter are summarized below (in millions):



	Projected Benefit Payments
	Pension		Other Postretirement

2017	$	60	$	18
2018	60		19
2019	62		20
2020	62		21
2021	60		21
2022-2026	278		97

Fair Value, Assets and Liabilities Measured on Recurring Basis [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, 2016:



	Pension	Other Postretirement
	%	%
Debt securities⁽¹⁾	20-40	25-45
Equity securities⁽¹⁾	60-80	50-80
Real estate funds	2-8	—
Other	0-5	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.

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, 2016:
Cash equivalents	$	—	$	17	$	—	$	17
Debt securities:
United States government obligations	9		—		—		9
Corporate obligations	—		53		—		53
Municipal obligations	—		6		—		6
Agency, asset and mortgage-backed obligations	—		22		—		22
Equity securities:
United States companies	130		—		—		130
International equity securities	39		—		—		39
Investment funds⁽²⁾	63		—		—		63
Total assets in the hierarchy	$	241	$	98	$	—	339
Investment funds⁽²⁾ measured at net asset value							295
Real estate funds measured at net asset value							50
Total assets measured at fair value							$	684

As of December 31, 2015:
Cash equivalents	$	—	$	16	$	—	$	16
Debt securities:
United States government obligations	5		—		—		5
Corporate obligations	—		57		—		57
Municipal obligations	—		6		—		6
Agency, asset and mortgage-backed obligations	—		27		—		27
Equity securities:
United States companies	130		—		—		130
International equity securities	40		—		—		40
Investment funds⁽²⁾	61		—		—		61
Total assets in the hierarchy	$	236	$	106	$	—	342
Investment funds⁽²⁾ measured at net asset value							296
Real estate funds measured at net asset value							40
Total assets measured at fair value							$	678


(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 74% and 26%, respectively, for 2016 and 72% and 28%, respectively, for 2015. Additionally, these funds are invested in United States and international securities of approximately 71% and 29%, respectively, for 2016 and 73% and 27%, respectively, for 2015.

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, 2016:
Cash equivalents	$	10	$	—	$	—	$	10
Debt securities:
United States government obligations	5		—		—		5
Corporate obligations	—		11		—		11
Municipal obligations	—		37		—		37
Agency, asset and mortgage-backed obligations	—		11		—		11
Equity securities:
United States companies	122		—		—		122
Investment funds⁽²⁾	56		—		—		56
Total assets measured at fair value	$	193	$	59	$	—	$	252

As of December 31, 2015:
Cash equivalents	$	5	$	—	$	—	$	5
Debt securities:
United States government obligations	5		—		—		5
Corporate obligations	—		12		—		12
Municipal obligations	—		39		—		39
Agency, asset and mortgage-backed obligations	—		12		—		12
Equity securities:
United States companies	120		—		—		120
Investment funds⁽²⁾	56		—		—		56
Total assets measured at fair value	$	186	$	63	$	—	$	249


(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 70% and 30%, respectively, for 2016 and 68% and 32%, respectively, for 2015. Additionally, these funds are invested in United States and international securities of approximately 30% and 70%, respectively, for 2016 and 32% and 68%, respectively, for 2015.

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, 2016:
Assets:
Commodity derivatives	$	—		$	9		$	1		$	(2	)	$	8
Money market mutual funds⁽²⁾	1			—			—			—			1
Debt securities:
United States government obligations	161			—			—			—			161
International government obligations	—			3			—			—			3
Corporate obligations	—			36			—			—			36
Municipal obligations	—			2			—			—			2
Agency, asset and mortgage-backed obligations	—			2			—			—			2
Equity securities:
United States companies	250			—			—			—			250
International companies	5			—			—			—			5
Investment funds	9			—			—			—			9
	$	426		$	52		$	1		$	(2	)	$	477

Liabilities - commodity derivatives	$	—		$	(3	)	$	(3	)	$	3		$	(3	)

As of December 31, 2015
Assets:
Commodity derivatives	$	—		$	8		$	18		$	(13	)	$	13
Money market mutual funds⁽²⁾	56			—			—			—			56
Debt securities:
United States government obligations	133			—			—			—			133
International government obligations	—			2			—			—			2
Corporate obligations	—			39			—			—			39
Municipal obligations	—			1			—			—			1
Agency, asset and mortgage-backed obligations	—			3			—			—			3
Auction rate securities	—			—			26			—			26
Equity securities:
United States companies	239			—			—			—			239
International companies	6			—			—			—			6
Investment funds	4			—			—			—			4
	$	438		$	53		$	44		$	(13	)	$	522

Liabilities - commodity derivatives	$	(13	)	$	(61	)	$	(24	)	$	41		$	(57	)


(1)	Represents netting under master netting arrangements and a net cash collateral receivable of $1 million and $28 million as of December 31, 2016 and 2015, respectively.


(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]