Restructuring Charges (Schedule Of Accrued Restructuring Balances) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 1,091us-gaap_RestructuringReserve	$ 717us-gaap_RestructuringReserve
Restructuring charges	1,049us-gaap_RestructuringCharges	7,084us-gaap_RestructuringCharges
Cash Payment	(1,809)us-gaap_PaymentsForRestructuring	(4,997)us-gaap_PaymentsForRestructuring
Non-Cash Activity	(344)	(1,690)
Foreign Exchange Adjustments	13	(23)
Ending Balance	0us-gaap_RestructuringReserve	1,091us-gaap_RestructuringReserve
2014 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0
Restructuring charges	879
Cash Payment	(879)
Non-Cash Activity	0
Foreign Exchange Adjustments	0
Ending Balance	0
2013 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	953	0
Restructuring charges	186	5,590
Cash Payment	(820)	(3,387)
Non-Cash Activity	(344)	(1,224)
Foreign Exchange Adjustments	25	(26)
Ending Balance	0	953
2012 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	138	704
Restructuring charges	(16)	1,596
Cash Payment	(110)	(1,697)
Non-Cash Activity	0	(466)
Foreign Exchange Adjustments	(12)	1
Ending Balance	0	138
2011 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance		13
Restructuring charges		(102)
Cash Payment		87
Non-Cash Activity		0
Foreign Exchange Adjustments		2
Ending Balance		0
Severance [Member] \| 2014 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0
Restructuring charges	876
Cash Payment	(876)
Non-Cash Activity	0
Foreign Exchange Adjustments	0
Ending Balance	0
Severance [Member] \| 2013 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	120	0
Restructuring charges	87	2,202
Cash Payment	(193)	(2,003)
Non-Cash Activity	0	0
Foreign Exchange Adjustments	(14)	(79)
Ending Balance	0	120
Severance [Member] \| 2012 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	34	538
Restructuring charges	45	660
Cash Payment	(79)	(1,262)
Non-Cash Activity	0	0
Foreign Exchange Adjustments	0	98
Ending Balance	0	34
Lease Facility Costs [Member] \| 2013 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance		0
Restructuring charges		142
Cash Payment		(139)
Non-Cash Activity		0
Foreign Exchange Adjustments		(3)
Ending Balance		0
Lease Facility Costs [Member] \| 2012 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance		0
Restructuring charges		798
Cash Payment		(328)
Non-Cash Activity		(466)
Foreign Exchange Adjustments		(4)
Ending Balance		0
Lease Facility Costs [Member] \| 2011 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance		13
Restructuring charges		(102)
Cash Payment		87
Non-Cash Activity		0
Foreign Exchange Adjustments		2
Ending Balance		0
Other Exit Costs [Member] \| 2014 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0
Restructuring charges	3
Cash Payment	(3)
Non-Cash Activity	0
Foreign Exchange Adjustments	0
Ending Balance	0
Other Exit Costs [Member] \| 2013 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	833	0
Restructuring charges	99	3,246
Cash Payment	(627)	(1,245)
Non-Cash Activity	(344)	(1,224)
Foreign Exchange Adjustments	39	56
Ending Balance	0	833
Other Exit Costs [Member] \| 2012 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	104	166
Restructuring charges	(61)	138
Cash Payment	(31)	(107)
Non-Cash Activity	0
Foreign Exchange Adjustments	(12)	(93)
Ending Balance	$ 0	$ 104

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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

- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b))

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 5.P.3)

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140864-122747

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

+ Details

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

- Details

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

- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b))

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

+ Details

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

- Definition

Amount of consideration other than cash used to fully or partially settle an accrued restructuring cost.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b)(2))

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringReserveSettledWithoutCash1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of foreign currency translation adjustment increasing or decreasing the accrual for a specified type of restructuring cost.

+ References

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b)(2))

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)(2)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

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

- Details

Name:	us-gaap_ReserveQuantitiesByTypeOfReserveAxis=bhe_OtherexitcostsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReserveQuantitiesByTypeOfReserveAxis=us-gaap_EmployeeSeveranceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReserveQuantitiesByTypeOfReserveAxis=us-gaap_FacilityClosingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=bhe_TwoThousandAndFourteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=bhe_TwoThousandAndThirteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=bhe_TwoThousandAndTwelveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=bhe_TwoThousandElevenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: