Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

New Accounting Pronouncements, Policy [Policy Text Block]

New Accounting Pronouncements

In January 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-01, which amends FASB Accounting Standards Codification ("ASC") Subtopic 825-10, "Financial Instruments - Overall." The amendments in this guidance address certain aspects of recognition, measurement, presentation and disclosure of financial instruments including a requirement that all investments in equity securities that do not qualify for equity method accounting or result in consolidation of the investee be measured at fair value with changes in fair value recognized in net income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption not permitted, and is required to be adopted prospectively by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. The Company is currently evaluating the impact of adopting this guidance on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements.

In November 2015, the FASB issued ASU No. 2015-17, which amends FASB ASC Topic 740, "Income Taxes." The amendments in this guidance require that deferred income tax liabilities and assets be classified as noncurrent in the balance sheet. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016, with early adoption permitted, and may be adopted prospectively or retrospectively for each period presented to reflect the new guidance. The Company early adopted this guidance as of December 31, 2015 under a retrospective method, resulting in decreases in other current assets of $291 million, other current liabilities of $3 million and noncurrent deferred income tax liabilities of $288 million as of December 31, 2014.

In April 2015, the FASB issued ASU No. 2015-03, which amends FASB ASC Subtopic 835-30, "Interest - Imputation of Interest." The amendments in this guidance require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability instead of as an asset. This guidance is effective for interim and annual reporting periods beginning after December 15, 2015, with early adoption permitted. This guidance must be adopted retrospectively, wherein the balance sheet of each period presented should be adjusted to reflect the new guidance. The Company early adopted this guidance as of December 31, 2015 under a retrospective method, resulting in a decrease in other assets of $197 million, BHE senior debt of $50 million and subsidiary debt of $147 million as of December 31, 2014.

In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. The Company is currently evaluating the impact of adopting this guidance on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements.

In January 2014, the FASB issued ASU No. 2014-05, which amends FASB ASC Topic 853, "Service Concession Arrangements" ("ASC 853"). The amendments in this guidance require an entity to not account for service concession arrangements as a lease and should also not recognize them as property, plant and equipment. This guidance is effective for interim and annual reporting periods beginning after December 15, 2014. The Company adopted this guidance effective January 1, 2015 under a modified retrospective method where the cumulative effect is recognized at the date of initial application. The adoption resulted in the establishment of a financial asset with a related recognition of interest income, the elimination of a portion of previously recognized property, plant and equipment, the elimination of recognizing guaranteed water and energy delivery fees in operating revenue and increases to retained earnings attributable to the Company of $56 million and noncontrolling interests of $11 million.

New Accounting Pronouncements

In November 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2015-17, which amends FASB Accounting Standards Codification ("ASC") Topic 740, "Income Taxes". The amendments in this guidance require that deferred income tax liabilities and assets be classified as noncurrent in the balance sheet. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016, with early adoption permitted, and may be adopted prospectively or retrospectively for each period presented to reflect the new guidance. Sierra Pacific early adopted this guidance as of December 31, 2015 under a retrospective method, resulting in decreases in current deferred income tax assets and noncurrent deferred income tax liabilities of $42 million as of December 31, 2014.

In April 2015, the FASB issued ASU No. 2015-03, which amends FASB ASC Subtopic 835-30, "Interest - Imputation of Interest." The amendments in this guidance require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability instead of as an asset. This guidance is effective for interim and annual reporting periods beginning after December 15, 2015, with early adoption permitted. This guidance must be adopted retrospectively, wherein the balance sheet of each period presented should be adjusted to reflect the new guidance. Sierra Pacific early adopted this guidance as of December 31, 2015 under a retrospective method, resulting in a decrease in other assets and long-term debt of $10 million as of December 31, 2014.

In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. Sierra Pacific is currently evaluating the impact of adopting this guidance on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements.

PacifiCorp [Member]

Accounting Policies [Abstract]

New Accounting Pronouncements, Policy [Policy Text Block]

New Accounting Pronouncements

In January 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-01, which amends FASB Accounting Standards Codification ("ASC") Subtopic 825-10, "Financial Instruments - Overall." The amendments in this guidance address certain aspects of recognition, measurement, presentation and disclosure of financial instruments including a requirement that all investments in equity securities that do not qualify for equity method accounting or result in consolidation of the investee be measured at fair value with changes in fair value recognized in net income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption not permitted, and is required to be adopted prospectively by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. PacifiCorp is currently evaluating the impact of adopting this guidance on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements.

In November 2015, the FASB issued ASU No. 2015-17, which amends ASC Topic 740, "Income Taxes". The amendments in this guidance require that deferred income tax liabilities and assets be classified as noncurrent in the balance sheet. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016, with early adoption permitted, and may be adopted prospectively or retrospectively for each period presented to reflect the new guidance. PacifiCorp early adopted this guidance as of December 31, 2015 under a retrospective method, resulting in decreases in current deferred income tax assets of $28 million and noncurrent deferred income tax liabilities of $28 million as of December 31, 2014.

In April 2015, the FASB issued ASU No. 2015-03, which amends FASB ASC Subtopic 835-30, "Interest - Imputation of Interest." The amendments in this guidance require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability instead of as an asset. This guidance is effective for interim and annual reporting periods beginning after December 15, 2015, with early adoption permitted, and must be adopted retrospectively for each period presented to reflect the new guidance. PacifiCorp early adopted this guidance as of December 31, 2015 under a retrospective method, resulting in a decrease in other assets of $34 million and long-term debt of $34 million as of December 31, 2014.

In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. PacifiCorp is currently evaluating the impact of adopting this guidance on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements.

Allowance for Doubtful Accounts [Line Items]

Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]

Property, plant and equipment, net consists of the following as of December 31 (in millions):



	Depreciable Life	2015			2014
Property, plant and equipment:
Generation	10 - 67 years	$	12,164		$	11,932
Transmission	58 - 75 years	5,914			5,392
Distribution	20 - 70 years	6,408			6,197
Intangible plant⁽¹⁾	5 - 62 years	875			879
Other	5 - 60 years	1,396			1,413
Property, plant and equipment in-service		26,757			25,813
Accumulated depreciation and amortization		(8,360		)	(8,026		)
Net property, plant and equipment in-service		18,397			17,787
Construction work-in-progress		629			932
Total property, plant and equipment, net		$	19,026		$	18,719


(1)	Computer software costs included in intangible plant are initially assigned a depreciable life of 5 to 10 years.

Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]

The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions):



	2015			2014			2013

Beginning balance	$	7		$	8		$	9
Charged to operating costs and expenses, net	10			11			13
Write-offs, net	(10		)	(12		)	(14		)
Ending balance	$	7		$	7		$	8

MidAmerican Energy Company [Member]

Accounting Policies [Abstract]

New Accounting Pronouncements, Policy [Policy Text Block]

New Accounting Pronouncements

In January 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-01, which amends FASB Accounting Standards Codification ("ASC") Subtopic 825-10, "Financial Instruments - Overall." The amendments in this guidance address certain aspects of recognition, measurement, presentation and disclosure of financial instruments including a requirement that all investments in equity securities that do not qualify for equity method accounting or result in consolidation of the investee be measured at fair value with changes in fair value recognized in net income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption not permitted, and is required to be adopted prospectively by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. MidAmerican Energy is currently evaluating the impact of adopting this guidance on its Financial Statements and disclosures included within Notes to Financial Statements.

In November 2015, the FASB issued ASU No. 2015-17, which amends FASB ASC Topic 740, "Income Taxes." The amendments in this guidance require that deferred income tax liabilities and assets be classified as noncurrent in the balance sheet. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016, with early adoption permitted, and may be adopted prospectively or retrospectively for each period presented to reflect the new guidance. MidAmerican Energy early adopted this guidance as of December 31, 2015, under a retrospective method, resulting in a decrease of $1 million each in other current assets and noncurrent deferred income tax liabilities as of December 31, 2014.

In April 2015, the FASB issued ASU No. 2015-03, which amends FASB ASC Subtopic 835-30, "Interest - Imputation of Interest." The amendments in this guidance require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability instead of as an asset. This guidance is effective for interim and annual reporting periods beginning after December 15, 2015, with early adoption permitted. This guidance must be adopted retrospectively, wherein the balance sheet of each period presented should be adjusted to reflect the new guidance. MidAmerican Energy early adopted this guidance as of December 31, 2015, under a retrospective method, resulting in a decrease of $22 million each in other assets and long-term debt as of December 31, 2014.

In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016. Early application is not permitted. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. MidAmerican Energy is currently evaluating the impact of adopting this guidance on its Financial Statements and disclosures included within Notes to Financial Statements.

Allowance for Doubtful Accounts [Line Items]

Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]

Property, plant and equipment, net consists of the following as of December 31 (in millions):



	Depreciable Life	2015			2014

Utility plant in service:
Generation	20-100 years	$	10,404		$	9,351
Transmission	52-70 years	1,305			1,142
Electric distribution	20-70 years	3,059			2,933
Gas distribution	28-70 years	1,507			1,432
Utility plant in service		16,275			14,858
Accumulated depreciation and amortization		(5,229		)	(4,954		)
Utility plant in service, net		11,046			9,904
Nonregulated property, net:
Nonregulated property gross	5-45 years	15			14
Accumulated depreciation and amortization		(5		)	(5		)
Nonregulated property, net		10			9
		11,056			9,913
Construction work in progress		667			606
Property, plant and equipment, net		$	11,723		$	10,519

Nevada Power Company [Member]

Accounting Policies [Abstract]

New Accounting Pronouncements, Policy [Policy Text Block]

New Accounting Pronouncements

In November 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2015-17, which amends FASB Accounting Standards Codification ("ASC") Topic 740, "Income Taxes". The amendments in this guidance require that deferred income tax liabilities and assets be classified as noncurrent in the balance sheet. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016, with early adoption permitted, and may be adopted prospectively or retrospectively for each period presented to reflect the new guidance. Nevada Power early adopted this guidance as of December 31, 2015 under a retrospective method, resulting in decreases in current deferred income tax assets and noncurrent deferred income tax liabilities of $145 million as of December 31, 2014.

In April 2015, the FASB issued ASU No. 2015-03, which amends FASB ASC Subtopic 835-30, "Interest - Imputation of Interest." The amendments in this guidance require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability instead of as an asset. This guidance is effective for interim and annual reporting periods beginning after December 15, 2015, with early adoption permitted. This guidance must be adopted retrospectively, wherein the balance sheet of each period presented should be adjusted to reflect the new guidance. Nevada Power early adopted this guidance as of December 31, 2015 under a retrospective method, resulting in a decrease in other assets and long-term debt of $32 million as of December 31, 2014.

In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. Nevada Power is currently evaluating the impact of adopting this guidance on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements.

Allowance for Doubtful Accounts [Line Items]

Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]

Property, plant and equipment, net consists of the following as of December 31 (in millions):



	Depreciable Life	2015			2014
Utility plant:
Generation	25 - 80 years	$	4,212		$	4,034
Distribution	20 - 65 years	3,118			3,018
Transmission	45 - 65 years	1,788			1,757
General and intangible plant	5 - 65 years	694			669
Utility plant		9,812			9,478
Accumulated depreciation and amortization		(2,971		)	(2,599		)
Utility plant, net		6,841			6,879
Other non-regulated, net of accumulated depreciation and amortization	5 - 65 years	2			4
Plant, net		6,843			6,883
Construction work-in-progress		153			120
Property, plant and equipment, net		$	6,996		$	7,003

Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]



	2015			2014			2013
Beginning balance	$	14		$	8		$	8
Charged to operating costs and expenses, net	16			14			15
Write-offs, net	(17		)	(8		)	(15		)
Ending balance	$	13		$	14		$	8

Sierra Pacific Power Company [Member]

Allowance for Doubtful Accounts [Line Items]

Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]

Property, plant and equipment, net consists of the following as of December 31 (in millions):



	Depreciable Life	2015			2014
Utility plant:
Electric generation	40 - 125 years	$	1,134		$	1,036
Electric distribution	20 - 70 years	1,382			1,321
Electric transmission	50 - 70 years	739			719
Electric general and intangible plant	5 - 65 years	139			123
Natural gas distribution	40 - 70 years	374			366
Natural gas general and intangible plant	8 - 10 years	13			13
Common general	5 - 65 years	265			234
Utility plant		4,046			3,812
Accumulated depreciation and amortization		(1,368		)	(1,300		)
Utility plant, net		2,678			2,512
Construction work-in-progress		88			128
Property, plant and equipment, net		$	2,766		$	2,640

Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]



	2015			2014			2013
Beginning balance	$	2		$	1		$	1
Charged to operating costs and expenses, net	1			2			2
Write-offs, net	(2		)	(1		)	(2		)
Ending balance	$	1		$	2		$	1