Name:	bhe_ActualCommonEquityPercentageAsCalculatedInAccordanceWithAcquisitionCommitment
Namespace Prefix:	bhe_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the minimum common equity to total capitalization percentage, excluding short-term debt and current maturities of long-term debt, allowed under acquisition commitments without prior regulatory approval of dividends.

No definition available.

Name:	bhe_MinimumCommonEquityToCapitalizationPercentage
Namespace Prefix:	bhe_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The percentage of preferred stock in existence prior to acquisition to be treated as common equity when calculating common equity to defined capitalization percentage according to the terms of the state regulatory orders.

No definition available.

Name:	bhe_PercentageOfPreferredStockToBeTreatedAsCommonEquityForCommonEquityPercentageCalculation
Namespace Prefix:	bhe_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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

Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Name:	us-gaap_DividendsCommonStockCash
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of dividends that can be declared or paid without approval of regulatory agency.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690