Name:	bhe_CashAndInvestmentsRestricted
Namespace Prefix:	bhe_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Carrying amount of all investments in debt and equity securities categorized as available-for-sale securities, reported at fair value. Includes restricted cash and investments primarily related to (a) funds held in trust for nuclear decommissioning and (b) debt service requirements that are restricted by certain project debt agreements to be used only for the related project. Includes equity method investments. Includes Rabbi trusts that hold corporate-owned life insurance on certain key executives and directors and represents the cash surrender value, net of any amounts borrowed against the cash surrender value.

No definition available.

Name:	bhe_InvestmentsIncludingEquityMethodAndRestrictedCashAndInvestments
Namespace Prefix:	bhe_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Carrying amount of investments in debt and equity securities categorized as available-for-sale securities, reported at fair value and expected to be used in operations within one year or the normal operating cycle, if longer. Includes restricted cash and investments primarily related to (a) funds held in trust for nuclear decommissioning and (b) debt service requirements that are restricted by certain project debt agreements to be used only for the related project. Includes equity method investments. Includes Rabbi trusts that hold corporate-owned life insurance on certain key executives and directors and represents the cash surrender value, net of any amounts borrowed against the cash surrender value.

No definition available.

Name:	bhe_InvestmentsIncludingEquityMethodAndRestrictedCashAndInvestmentsCurrent
Namespace Prefix:	bhe_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Carrying amount of investments in debt and equity securities categorized as available-for-sale securities, reported at fair value and not expected to be used in operations within one year or the normal operating cycle, if longer. Includes restricted cash and investments primarily related to (a) funds held in trust for nuclear decommissioning and (b) debt service requirements that are restricted by certain project debt agreements to be used only for the related project. Includes equity method investments. Includes Rabbi trusts that hold corporate-owned life insurance on certain key executives and directors and represents the cash surrender value, net of any amounts borrowed against the cash surrender value.

No definition available.

Name:	bhe_InvestmentsIncludingEquityMethodAndRestrictedCashAndInvestmentsNoncurrent
Namespace Prefix:	bhe_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of equity securities categorized neither as held-to-maturity nor as trading.

No definition available.

Name:	us-gaap_AvailableForSaleSecuritiesEquitySecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The fair value of investments held in a trust fund to pay for the costs of decontaminating and decommissioning facilities, whether such amount is presented as a separate caption or as a parenthetical disclosure on the balance sheet. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Name:	us-gaap_DecommissioningTrustAssetsAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

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

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 25
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8813-108599

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_EquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of realized and unrealized gain (loss) on investment.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27405-111563

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(c),9(a))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Name:	us-gaap_GainLossOnInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Sum of the carrying amounts as of the balance sheet date of all investments.

Name:	us-gaap_Investments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

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

This item represents the amount that could be realized under a life insurance contract or contracts owned by the Entity as of the date of the statement of financial position. Such Entity-owned life insurance policies are commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 325
-SubTopic 30
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6384206&loc=d3e41899-111602

Name:	us-gaap_LifeInsuranceCorporateOrBankOwnedAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of realized gain (loss) on investment in marketable security, including other-than-temporary impairment (OTTI).

No definition available.

Name:	us-gaap_MarketableSecuritiesRealizedGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of unrealized gain (loss) on investment in marketable security.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

Name:	us-gaap_MarketableSecuritiesUnrealizedGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of investments classified as other.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(f,g))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_OtherInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

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

Name:	bhe_RestrictedCashAndInvestmentsAxis=bhe_NuclearDecommissioningTrustFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	bhe_RestrictedCashAndInvestmentsAxis=bhe_RestrictedCashAndInvestmentsOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=bhe_EquityMethodInvestmentstaxequityinvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=bhe_EquityMethodInvestmentsElectricTransmissionTexasLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=bhe_EquityMethodInvestmentsBridgerCoalCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=bhe_EquityMethodInvestmentsOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_InvestmentTypeAxis=bhe_BydCompanyLimitedCommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_InvestmentTypeAxis=bhe_RabbiTrustMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: