Subsidiary Debt - BHE Pipeline Group (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Par value	$ 38,593us-gaap_DebtInstrumentFaceAmount
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	26,924
Other long-term debt	26,995	22,802
BHE Pipeline Group [Member] \| Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	1,367
Other long-term debt	1,366	1,448
Kern River [Member] \| Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	467
Other long-term debt	467	548
Kern River [Member] \| Subsidiary Debt [Member] \| Senior Notes, 6.676%, due 2016 [Member]
Debt Instrument [Line Items]
Par value	167
Other long-term debt	167	197
Kern River [Member] \| Subsidiary Debt [Member] \| Senior Notes, 4.893%, due 2018 [Member]
Debt Instrument [Line Items]
Par value	300
Other long-term debt	300	351
Northern Natural Gas [Member] \| Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	900
Other long-term debt	899	900
Northern Natural Gas [Member] \| Subsidiary Debt [Member] \| Senior Notes, 5.125%, due 2015 [Member]
Debt Instrument [Line Items]
Par value	100
Other long-term debt	100	100
Northern Natural Gas [Member] \| Subsidiary Debt [Member] \| Senior Notes, 5.75%, due 2018 [Member]
Debt Instrument [Line Items]
Par value	200
Other long-term debt	200	200
Northern Natural Gas [Member] \| Subsidiary Debt [Member] \| Senior Notes, 4.25%, due 2021 [Member]
Debt Instrument [Line Items]
Par value	200
Other long-term debt	200	200
Northern Natural Gas [Member] \| Subsidiary Debt [Member] \| Senior Bonds, 5.8%, due 2037 [Member]
Debt Instrument [Line Items]
Par value	150
Other long-term debt	150	150
Northern Natural Gas [Member] \| Subsidiary Debt [Member] \| Senior Bonds, 4.1%, due 2042 [Member]
Debt Instrument [Line Items]
Par value	250
Other long-term debt	249	250
Kern River [Member] \| BHE Pipeline Group [Member] \| Subsidiary Debt [Member] \| Senior Notes, 6.676%, due 2016 [Member]
Debt Instrument [Line Items]
Stated interest rate	6.676%	6.676%
Kern River [Member] \| BHE Pipeline Group [Member] \| Subsidiary Debt [Member] \| Senior Notes, 4.893%, due 2018 [Member]
Debt Instrument [Line Items]
Stated interest rate	4.893%	4.893%
Kern River [Member] \| Letter of Credit [Member] \| BHE Pipeline Group [Member]
Debt Instrument [Line Items]
Letters of credit outstanding, amount	$ 56	$ 56
Northern Natural Gas [Member] \| BHE Pipeline Group [Member] \| Subsidiary Debt [Member] \| Senior Notes, 5.125%, due 2015 [Member]
Debt Instrument [Line Items]
Stated interest rate	5.125%	5.125%
Northern Natural Gas [Member] \| BHE Pipeline Group [Member] \| Subsidiary Debt [Member] \| Senior Notes, 5.75%, due 2018 [Member]
Debt Instrument [Line Items]
Stated interest rate	5.75%	5.75%
Northern Natural Gas [Member] \| BHE Pipeline Group [Member] \| Subsidiary Debt [Member] \| Senior Notes, 4.25%, due 2021 [Member]
Debt Instrument [Line Items]
Stated interest rate	4.25%	4.25%
Northern Natural Gas [Member] \| BHE Pipeline Group [Member] \| Subsidiary Debt [Member] \| Senior Bonds, 5.8%, due 2037 [Member]
Debt Instrument [Line Items]
Stated interest rate	5.80%	5.80%
Northern Natural Gas [Member] \| BHE Pipeline Group [Member] \| Subsidiary Debt [Member] \| Senior Bonds, 4.1%, due 2042 [Member]
Debt Instrument [Line Items]
Stated interest rate	4.10%	4.10%

Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Including both current and noncurrent portions, carrying amount as of the balance sheet date of other forms of debt not elsewhere specified in the taxonomy with initial maturities beyond one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

+ Details

Name:	us-gaap_OtherLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	bhe_LongTermDebtIssuerAxis=bhe_KernRiverMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bhe_LongTermDebtIssuerAxis=bhe_NorthernNaturalGasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=bhe_KernRiverMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=bhe_NorthernNaturalGasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=bhe_SubsidiaryDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bhe_MidamericanEnergyPipelineGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: