<?xml version="1.0" encoding="utf-8"?>
<FilingSummary xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Version>2.4.0.8</Version>
  <ProcessingTime />
  <ReportFormat>Html</ReportFormat>
  <ContextCount>170</ContextCount>
  <ElementCount>266</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>50</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>7</UnitCount>
  <MyReports>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000090 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document And Entity Information</ShortName>
    </Report>
    <Report>
      <IsDefault>true</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>000100 - Statement - Condensed Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/StatementCondensedConsolidatedBalanceSheets</Role>
      <ShortName>Condensed Consolidated Balance Sheets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>000105 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>000200 - Statement - Condensed Consolidated Statements Of Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/StatementCondensedConsolidatedStatementsOfIncome</Role>
      <ShortName>Condensed Consolidated Statements Of Income</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>000300 - Statement - Condensed Consolidated Statements of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Income</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>000400 - Statement - Condensed Consolidated Statements Of Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/StatementCondensedConsolidatedStatementsOfShareholdersEquity</Role>
      <ShortName>Condensed Consolidated Statements Of Shareholders' Equity</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>000500 - Statement - Condensed Consolidated Statements Of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/StatementCondensedConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Condensed Consolidated Statements Of Cash Flows</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>010101 - Disclosure - Basis Of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureBasisOfPresentation</Role>
      <ShortName>Basis Of Presentation</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>010201 - Disclosure - Stock Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/StockBasedCompensation</Role>
      <ShortName>Stock Based Compensation</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>010301 - Disclosure - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureEarningsPerShare</Role>
      <ShortName>Earnings Per Share</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>010401 - Disclosure - Goodwill And Other Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureGoodwillAndOtherIntangibleAssets</Role>
      <ShortName>Goodwill And Other Intangible Assets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>010501 - Disclosure - Borrowing Facilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureBorrowingFacilities</Role>
      <ShortName>Borrowing Facilities</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>010601 - Disclosure - Inventories</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureInventories</Role>
      <ShortName>Inventories</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>010701 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>010801 - Disclosure - Segment And Geographic Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureSegmentAndGeographicInformation</Role>
      <ShortName>Segment And Geographic Information</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>010901 - Disclosure - Supplemental Cash Flow Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureSupplementalCashFlowInformation</Role>
      <ShortName>Supplemental Cash Flow Information</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>011001 - Disclosure - Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureContingencies</Role>
      <ShortName>Contingencies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>011101 - Disclosure - Impact Of Recently Enacted Accounting Standards</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureImpactOfRecentlyEnactedAccountingStandards</Role>
      <ShortName>Impact Of Recently Enacted Accounting Standards</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>011201 - Disclosure - Restructuring Charges</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/RestructuringCharges</Role>
      <ShortName>Restructuring Charges</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>011301 - Disclosure - Fair Value</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureFairValue</Role>
      <ShortName>Fair Value</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>011401 - Disclosure - Thailand Flood Related Items</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/ThailandFloodRelatedItems</Role>
      <ShortName>Thailand Flood Related Items</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>011501 - Disclosure - Acquisition</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/Acquisition</Role>
      <ShortName>Acquisition</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>011601 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>030203 - Disclosure - Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureStockBasedCompensationTables</Role>
      <ShortName>Stock-Based Compensation (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>030303 - Disclosure - Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureEarningsPerShareTables</Role>
      <ShortName>Earnings Per Share (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>030403 - Disclosure - Goodwill And Other Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureGoodwillAndOtherIntangibleAssetsTables</Role>
      <ShortName>Goodwill And Other Intangible Assets (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>030603 - Disclosure - Inventories (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureInventoriesTables</Role>
      <ShortName>Inventories (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>030703 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>030803 - Disclosure - Segment And Geographic Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureSegmentAndGeographicInformationTables</Role>
      <ShortName>Segment And Geographic Information (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>030903 - Disclosure - Supplemental Cash Flow Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureSupplementalCashFlowInformationTables</Role>
      <ShortName>Supplemental Cash Flow Information (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>031203 - Disclosure - Restructuring Charges (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureRestructuringChargesTables</Role>
      <ShortName>Restructuring Charges (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>031303 - Disclosure - Fair Value (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureFairValueTables</Role>
      <ShortName>Fair Value (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>031503 - Disclosure - Acquisitions (Table)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureAcquisitionsTable</Role>
      <ShortName>Acquisitions (Table)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>040201 - Disclosure - Stock-Based Compensation (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureStockBasedCompensationNarrativeDetails</Role>
      <ShortName>Stock-Based Compensation (Narrative) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>040202 - Disclosure - Stock-Based Compensation (Schedule Of Unrecognized Compensation Cost And Remaining Weighted-Average Amortization Period) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureStockBasedCompensationScheduleOfUnrecognizedCompensationCostAndRemainingWeightedAverageAmortizationPeriodDetails</Role>
      <ShortName>Stock-Based Compensation (Schedule Of Unrecognized Compensation Cost And Remaining Weighted-Average Amortization Period) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>040203 - Disclosure - Stock-Based Compensation (Weighted-Average Assumptions) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/StockBasedCompensationWeightedAverageAssumptionsDetails</Role>
      <ShortName>Stock-Based Compensation (Weighted-Average Assumptions) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>040204 - Disclosure - Stock-Based Compensation (Summary Of Stock Options) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/StockBasedCompensationSummaryOfStockOptionsDetails</Role>
      <ShortName>Stock-Based Compensation (Summary Of Stock Options) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>040205 - Disclosure - Stock-Based Compensation (Summary Of Stock-Based Awards) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/StockBasedCompensationSummaryOfStockBasedAwardsDetails</Role>
      <ShortName>Stock-Based Compensation (Summary Of Stock-Based Awards) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>040301 - Disclosure - Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureEarningsPerShareDetails</Role>
      <ShortName>Earnings Per Share (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>040401 - Disclosure - Goodwill And Other Intangible Assets (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureGoodwillAndOtherIntangibleAssetsNarrativeDetails</Role>
      <ShortName>Goodwill And Other Intangible Assets (Narrative) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>040402 - Disclosure - Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureGoodwillAndOtherIntangibleAssetsScheduleOfOtherIntangibleAssetsDetails</Role>
      <ShortName>Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>040403 - Disclosure - Goodwill And Other Intangible Assets (Schedule Of Estimated Future Amortization Expense) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureGoodwillAndOtherIntangibleAssetsScheduleOfEstimatedFutureAmortizationExpenseDetails</Role>
      <ShortName>Goodwill And Other Intangible Assets (Schedule Of Estimated Future Amortization Expense) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>040501 - Disclosure - Borrowing Facilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureBorrowingFacilitiesDetails</Role>
      <ShortName>Borrowing Facilities (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>040601 - Disclosure - Inventories (Schedule Of Inventory Costs) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureInventoriesScheduleOfInventoryCostsDetails</Role>
      <ShortName>Inventories (Schedule Of Inventory Costs) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>040701 - Disclosure - Income Taxes (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureIncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes (Narrative) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>040702 - Disclosure - Income Taxes (Schedule Of Income Tax Expense (Benefit)) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/2011-06-30/role/DisclosureIncomeTaxesScheduleOfIncomeTaxExpenseBenefitDetails</Role>
      <ShortName>Income Taxes (Schedule Of Income Tax Expense (Benefit)) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>040703 - Disclosure - Income Taxes (Schedule Of Tax Incentives) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureIncomeTaxesScheduleOfTaxIncentivesDetails</Role>
      <ShortName>Income Taxes (Schedule Of Tax Incentives) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>040801 - Disclosure - Segment And Geographic Information (Operating Segments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureSegmentAndGeographicInformationOperatingSegmentsDetails</Role>
      <ShortName>Segment And Geographic Information (Operating Segments) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>040802 - Disclosure - Segment And Geographic Information (Schedule Of Geographic Net Sales And Long-Lived Assets) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureSegmentAndGeographicInformationScheduleOfGeographicNetSalesAndLongLivedAssetsDetails</Role>
      <ShortName>Segment And Geographic Information (Schedule Of Geographic Net Sales And Long-Lived Assets) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>040901 - Disclosure - Supplemental Cash Flow (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureSupplementalCashFlowNarrativeDetails</Role>
      <ShortName>Supplemental Cash Flow (Narrative) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>040902 - Disclosure - Supplemental Cash Flow Information (Schedule Of Supplemental Cash Flow Information) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/SupplementalCashFlowInformationScheduleOfSupplementalCashFlowInformationDetails</Role>
      <ShortName>Supplemental Cash Flow Information (Schedule Of Supplemental Cash Flow Information) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>041201 - Disclosure - Restructuring Charges (Schedule Of Accrued Restructuring Balances) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureRestructuringChargesScheduleOfAccruedRestructuringBalancesDetails</Role>
      <ShortName>Restructuring Charges (Schedule Of Accrued Restructuring Balances) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>041301 - Disclosure - Fair Value (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureFairValueNarrativeDetails</Role>
      <ShortName>Fair Value (Narrative) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>041302 - Disclosure - Fair Value (Schedule Of Long-Term Investments Measured At Fair Value) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureFairValueScheduleOfLongTermInvestmentsMeasuredAtFairValueDetails</Role>
      <ShortName>Fair Value (Schedule Of Long-Term Investments Measured At Fair Value) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>041401 - Disclosure - Thailand Flood Related Items (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/ThailandFloodRelatedItemsDetails</Role>
      <ShortName>Thailand Flood Related Items (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>041501 - Disclosure - Acquisitions (Narratives) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureAcquisitionsNarrativesDetails</Role>
      <ShortName>Acquisitions (Narratives) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>041512 - Disclosure - Acquisitions (Schedule of Purchase Price Allocation) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureAcquisitionsScheduleOfPurchasePriceAllocationDetails</Role>
      <ShortName>Acquisitions (Schedule of Purchase Price Allocation) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>041601 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://bench.com/role/DisclosureSubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Info">Element us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity had a mix of decimals attribute values: -6 -5.</Log>
    <Log type="Info">Element us-gaap_PaymentsToAcquireBusinessesGross had a mix of decimals attribute values: -6 -3.</Log>
    <Log type="Info">'Shares' elements on report '040201 - Disclosure - Stock-Based Compensation (Narrative) (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Shares' elements on report '040301 - Disclosure - Earnings Per Share (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '040401 - Disclosure - Goodwill And Other Intangible Assets (Narrative) (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '040701 - Disclosure - Income Taxes (Narrative) (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '041301 - Disclosure - Fair Value (Narrative) (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '041501 - Disclosure - Acquisitions (Narratives) (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '041601 - Disclosure - Subsequent Events (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">Process Flow-Through: 000100 - Statement - Condensed Consolidated Balance Sheets</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Sep. 30, 2012'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2011'</Log>
    <Log type="Info">Process Flow-Through: 000105 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 000200 - Statement - Condensed Consolidated Statements Of Income</Log>
    <Log type="Info">Process Flow-Through: 000300 - Statement - Condensed Consolidated Statements of Comprehensive Income</Log>
    <Log type="Info">Process Flow-Through: 000500 - Statement - Condensed Consolidated Statements Of Cash Flows</Log>
  </Logs>
  <InputFiles>
    <File>bhe-20130930.xml</File>
    <File>bhe-20130930.xsd</File>
    <File>bhe-20130930_cal.xml</File>
    <File>bhe-20130930_def.xml</File>
    <File>bhe-20130930_lab.xml</File>
    <File>bhe-20130930_pre.xml</File>
  </InputFiles>
  <SupplementalFiles />
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
