<?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>2.4.1.9</Version>
  <ProcessingTime />
  <ReportFormat>Html</ReportFormat>
  <ContextCount>229</ContextCount>
  <ElementCount>343</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>65</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>10</UnitCount>
  <MyReports>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>100000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
    </Report>
    <Report>
      <IsDefault>true</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>100010 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>100020 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>100030 - Statement - Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/StatementConsolidatedStatementsOfOperations</Role>
      <ShortName>Consolidated Statements of Operations</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>100040 - Statement - Consolidated Statements of Comprehensive Loss</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/StatementConsolidatedStatementsOfComprehensiveLoss</Role>
      <ShortName>Consolidated Statements of Comprehensive Loss</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>100050 - Statement - Consolidated Statements of Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/StatementConsolidatedStatementsOfStockholdersEquity</Role>
      <ShortName>Consolidated Statements of Stockholders' Equity</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>100060 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>100070 - Disclosure - Organization and Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>100080 - Disclosure - Fair Value Measurement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureFairValueMeasurement</Role>
      <ShortName>Fair Value Measurement</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>100090 - Disclosure - Marketable Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMarketableSecurities</Role>
      <ShortName>Marketable Securities</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>100100 - Disclosure - Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockBasedCompensation</Role>
      <ShortName>Stock-Based Compensation</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>100110 - Disclosure - Major Customers, Partnerships and Strategic Alliances</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMajorCustomersPartnershipsAndStrategicAlliances</Role>
      <ShortName>Major Customers, Partnerships and Strategic Alliances</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>100120 - Disclosure - Acquisition of Ceregene</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureAcquisitionOfCeregene</Role>
      <ShortName>Acquisition of Ceregene</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>100130 - Disclosure - Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureIntangibleAssets</Role>
      <ShortName>Intangible Assets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>100140 - Disclosure - Property and Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosurePropertyAndEquipment</Role>
      <ShortName>Property and Equipment</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>100150 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>100160 - Disclosure - Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockholdersEquity</Role>
      <ShortName>Stockholders' Equity</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>100170 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>100180 - Disclosure - Accounts Payable and Accrued Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureAccountsPayableAndAccruedLiabilities</Role>
      <ShortName>Accounts Payable and Accrued Liabilities</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>100190 - Disclosure - Employee Benefit Plan</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureEmployeeBenefitPlan</Role>
      <ShortName>Employee Benefit Plan</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>100200 - Disclosure - Quarterly Financial Data (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureQuarterlyFinancialDataUnaudited</Role>
      <ShortName>Quarterly Financial Data (Unaudited)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>100210 - Disclosure - Organization and Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies (Policies)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>100220 - Disclosure - Fair Value Measurement (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureFairValueMeasurementTables</Role>
      <ShortName>Fair Value Measurement (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>100230 - Disclosure - Marketable Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMarketableSecuritiesTables</Role>
      <ShortName>Marketable Securities (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>100240 - Disclosure - Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockBasedCompensationTables</Role>
      <ShortName>Stock-Based Compensation (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>100250 - Disclosure - Major Customers, Partnerships and Strategic Alliances (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMajorCustomersPartnershipsAndStrategicAlliancesTables</Role>
      <ShortName>Major Customers, Partnerships and Strategic Alliances (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>100260 - Disclosure - Acquisition of Ceregene (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureAcquisitionOfCeregeneTables</Role>
      <ShortName>Acquisition of Ceregene (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>100270 - Disclosure - Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureIntangibleAssetsTables</Role>
      <ShortName>Intangible Assets (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>100280 - Disclosure - Property and Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosurePropertyAndEquipmentTables</Role>
      <ShortName>Property and Equipment (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>100290 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureCommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>100300 - Disclosure - Stockholders' Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockholdersEquityTables</Role>
      <ShortName>Stockholders' Equity (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>100310 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>100320 - Disclosure - Accounts Payable and Accrued Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureAccountsPayableAndAccruedLiabilitiesTables</Role>
      <ShortName>Accounts Payable and Accrued Liabilities (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>100330 - Disclosure - Quarterly Financial Data (Unaudited) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureQuarterlyFinancialDataUnauditedTables</Role>
      <ShortName>Quarterly Financial Data (Unaudited) (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>100340 - Disclosure - Organization and Summary of Significant Accounting Policies - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesAdditionalInformationDetail</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>100350 - Disclosure - Fair Value Measurement - Summary of Fair Value Measurements of Cash Equivalents, Available-for-Sale Securities and Contingent Consideration Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureFairValueMeasurementSummaryOfFairValueMeasurementsOfCashEquivalentsAvailableForSaleSecuritiesAndContingentConsiderationLiabilitiesDetail</Role>
      <ShortName>Fair Value Measurement - Summary of Fair Value Measurements of Cash Equivalents, Available-for-Sale Securities and Contingent Consideration Liabilities (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>100360 - Disclosure - Fair Value Measurement - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureFairValueMeasurementAdditionalInformationDetail</Role>
      <ShortName>Fair Value Measurement - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>100370 - Disclosure - Fair Value Measurement - Schedule of Changes in Estimated Fair Value of Contingent Consideration Liability (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureFairValueMeasurementScheduleOfChangesInEstimatedFairValueOfContingentConsiderationLiabilityDetail</Role>
      <ShortName>Fair Value Measurement - Schedule of Changes in Estimated Fair Value of Contingent Consideration Liability (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>100380 - Disclosure - Marketable Securities - Summary of Cash Equivalents and Available-for-Sale Securities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMarketableSecuritiesSummaryOfCashEquivalentsAndAvailableForSaleSecuritiesDetail</Role>
      <ShortName>Marketable Securities - Summary of Cash Equivalents and Available-for-Sale Securities (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>100390 - Disclosure - Marketable Securities - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMarketableSecuritiesAdditionalInformationDetail</Role>
      <ShortName>Marketable Securities - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>100400 - Disclosure - Stock-Based Compensation - Stock-Based Compensation Expense (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetail</Role>
      <ShortName>Stock-Based Compensation - Stock-Based Compensation Expense (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>100410 - Disclosure - Stock-Based Compensation - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail</Role>
      <ShortName>Stock-Based Compensation - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>100420 - Disclosure - Stock-Based Compensation - Assumptions Used for Estimating Fair Value of Employee Stock Options (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockBasedCompensationAssumptionsUsedForEstimatingFairValueOfEmployeeStockOptionsDetail</Role>
      <ShortName>Stock-Based Compensation - Assumptions Used for Estimating Fair Value of Employee Stock Options (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>100430 - Disclosure - Stock-Based Compensation - Weighted-Average Assumptions Used for Estimating Fair Value of ESPP Purchased Rights (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockBasedCompensationWeightedAverageAssumptionsUsedForEstimatingFairValueOfESPPPurchasedRightsDetail</Role>
      <ShortName>Stock-Based Compensation - Weighted-Average Assumptions Used for Estimating Fair Value of ESPP Purchased Rights (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>100440 - Disclosure - Major Customers, Partnerships and Strategic Alliances - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMajorCustomersPartnershipsAndStrategicAlliancesAdditionalInformationDetail</Role>
      <ShortName>Major Customers, Partnerships and Strategic Alliances - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>100450 - Disclosure - Major Customers, Partnerships and Strategic Alliances - Revenues Recognized under Agreement (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMajorCustomersPartnershipsAndStrategicAlliancesRevenuesRecognizedUnderAgreementDetail</Role>
      <ShortName>Major Customers, Partnerships and Strategic Alliances - Revenues Recognized under Agreement (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>100460 - Disclosure - Major Customers, Partnerships and Strategic Alliances - Agreement with Sigma-Aldrich Corporation - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMajorCustomersPartnershipsAndStrategicAlliancesAgreementWithSigmaAldrichCorporationAdditionalInformationDetail</Role>
      <ShortName>Major Customers, Partnerships and Strategic Alliances - Agreement with Sigma-Aldrich Corporation - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>100470 - Disclosure - Major Customers, Partnerships and Strategic Alliances - Agreement with Dow AgroSciences in Plant Agriculture - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMajorCustomersPartnershipsAndStrategicAlliancesAgreementWithDowAgrosciencesInPlantAgricultureAdditionalInformationDetail</Role>
      <ShortName>Major Customers, Partnerships and Strategic Alliances - Agreement with Dow AgroSciences in Plant Agriculture - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>100480 - Disclosure - Major Customers, Partnerships and Strategic Alliances - California Institute for Regenerative Medicine - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMajorCustomersPartnershipsAndStrategicAlliancesCaliforniaInstituteForRegenerativeMedicineAdditionalInformationDetail</Role>
      <ShortName>Major Customers, Partnerships and Strategic Alliances - California Institute for Regenerative Medicine - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>100490 - Disclosure - Major Customers, Partnerships and Strategic Alliances - CHDI Foundation, Inc. - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMajorCustomersPartnershipsAndStrategicAlliancesCHDIFoundationIncAdditionalInformationDetail</Role>
      <ShortName>Major Customers, Partnerships and Strategic Alliances - CHDI Foundation, Inc. - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>100500 - Disclosure - Major Customers, Partnerships and Strategic Alliances - Juvenile Diabetes Research Foundation International - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureMajorCustomersPartnershipsAndStrategicAlliancesJuvenileDiabetesResearchFoundationInternationalAdditionalInformationDetail</Role>
      <ShortName>Major Customers, Partnerships and Strategic Alliances - Juvenile Diabetes Research Foundation International - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>100510 - Disclosure - Acquisition of Ceregene - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureAcquisitionOfCeregeneAdditionalInformationDetail</Role>
      <ShortName>Acquisition of Ceregene - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>100520 - Disclosure - Acquisition of Ceregene - Summary of Estimated Fair Value of Consideration Transferred (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureAcquisitionOfCeregeneSummaryOfEstimatedFairValueOfConsiderationTransferredDetail</Role>
      <ShortName>Acquisition of Ceregene - Summary of Estimated Fair Value of Consideration Transferred (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>100530 - Disclosure - Acquisition of Ceregene - Summary of Estimated Fair Value of Net Assets Acquired (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureAcquisitionOfCeregeneSummaryOfEstimatedFairValueOfNetAssetsAcquiredDetail</Role>
      <ShortName>Acquisition of Ceregene - Summary of Estimated Fair Value of Net Assets Acquired (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>100540 - Disclosure - Acquisition of Ceregene - Summary of Assets, Estimated Fair Values (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureAcquisitionOfCeregeneSummaryOfAssetsEstimatedFairValuesDetail</Role>
      <ShortName>Acquisition of Ceregene - Summary of Assets, Estimated Fair Values (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>100550 - Disclosure - Intangible Assets - Carrying Value of Intangibles Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureIntangibleAssetsCarryingValueOfIntangiblesAssetsDetail</Role>
      <ShortName>Intangible Assets - Carrying Value of Intangibles Assets (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>100560 - Disclosure - Property and Equipment - Summary of Property and Equipment (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosurePropertyAndEquipmentSummaryOfPropertyAndEquipmentDetail</Role>
      <ShortName>Property and Equipment - Summary of Property and Equipment (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>100570 - Disclosure - Property and Equipment - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosurePropertyAndEquipmentAdditionalInformationDetail</Role>
      <ShortName>Property and Equipment - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>100580 - Disclosure - Commitments and Contingencies - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetail</Role>
      <ShortName>Commitments and Contingencies - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>100590 - Disclosure - Commitments and Contingencies - Summary of Future Minimum Payments under Contractual Obligations (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureCommitmentsAndContingenciesSummaryOfFutureMinimumPaymentsUnderContractualObligationsDetail</Role>
      <ShortName>Commitments and Contingencies - Summary of Future Minimum Payments under Contractual Obligations (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>100600 - Disclosure - Stockholders' Equity - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockholdersEquityAdditionalInformationDetail</Role>
      <ShortName>Stockholders' Equity - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>100610 - Disclosure - Stockholders' Equity - Summary of Stock Option Activity (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockholdersEquitySummaryOfStockOptionActivityDetail</Role>
      <ShortName>Stockholders' Equity - Summary of Stock Option Activity (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>100620 - Disclosure - Stockholders' Equity - Summary of Stock Options Outstanding (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockholdersEquitySummaryOfStockOptionsOutstandingDetail</Role>
      <ShortName>Stockholders' Equity - Summary of Stock Options Outstanding (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>100630 - Disclosure - Stockholders' Equity - Summary of Restricted Stock Unit Activity (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureStockholdersEquitySummaryOfRestrictedStockUnitActivityDetail</Role>
      <ShortName>Stockholders' Equity - Summary of Restricted Stock Unit Activity (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>100640 - Disclosure - Income Taxes - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail</Role>
      <ShortName>Income Taxes - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>100650 - Disclosure - Income Taxes - Schedule of Company's Deferred Tax Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureIncomeTaxesScheduleOfCompanySDeferredTaxAssetsDetail</Role>
      <ShortName>Income Taxes - Schedule of Company's Deferred Tax Assets (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>100660 - Disclosure - Income Taxes - Summary of Activity Related to Company's Unrecognized Tax Benefits (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureIncomeTaxesSummaryOfActivityRelatedToCompanySUnrecognizedTaxBenefitsDetail</Role>
      <ShortName>Income Taxes - Summary of Activity Related to Company's Unrecognized Tax Benefits (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>100670 - Disclosure - Accounts Payable and Accrued Liabilities - Summary of Accounts Payable and Accrued Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureAccountsPayableAndAccruedLiabilitiesSummaryOfAccountsPayableAndAccruedLiabilitiesDetail</Role>
      <ShortName>Accounts Payable and Accrued Liabilities - Summary of Accounts Payable and Accrued Liabilities (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>100680 - Disclosure - Employee Benefit Plan - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureEmployeeBenefitPlanAdditionalInformationDetail</Role>
      <ShortName>Employee Benefit Plan - Additional Information (Detail)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>100690 - Disclosure - Quarterly Financial Data (Unaudited) - Summary of Quarterly Financial Data (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.sangamo.com/20141231/taxonomy/role/DisclosureQuarterlyFinancialDataUnauditedSummaryOfQuarterlyFinancialDataDetail</Role>
      <ShortName>Quarterly Financial Data (Unaudited) - Summary of Quarterly Financial Data (Detail)</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 sgmo_AggregateAdditionalRevenueRecognitionMilestoneMethodRevenueEligibleToReceive had a mix of decimals attribute values: -6 -5.</Log>
    <Log type="Info">Element sgmo_NetProceedsFromIssuancePublicOffering had a mix of decimals attribute values: -5 -3.</Log>
    <Log type="Info">Element us-gaap_DeferredTaxAssetsValuationAllowance had a mix of decimals attribute values: -6 -3.</Log>
    <Log type="Info">Element us-gaap_ResearchAndDevelopmentExpense had a mix of decimals attribute values: -5 -3.</Log>
    <Log type="Info">Element us-gaap_RevenueFromGrants had a mix of decimals attribute values: -5 -3.</Log>
    <Log type="Info">Element us-gaap_RoyaltyRevenue had a mix of decimals attribute values: -5 -3.</Log>
    <Log type="Info">Element us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized had a mix of decimals attribute values: -5 0.</Log>
    <Log type="Info">Element us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent had a mix of decimals attribute values: 0 2.</Log>
    <Log type="Info">Element us-gaap_StockIssuedDuringPeriodValueNewIssues had a mix of decimals attribute values: -5 -3.</Log>
    <Log type="Info">Columns in Cash Flows statement 'Consolidated Statements of Cash Flows (USD $)' have maximum duration 365 days and at least 28 values. Shorter duration columns must have at least one fourth (7) as many values. Column '1/1/2013 - 3/31/2013' is shorter (89 days) and has only 2 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'Consolidated Statements of Cash Flows (USD $)' have maximum duration 365 days and at least 28 values. Shorter duration columns must have at least one fourth (7) as many values. Column '4/1/2013 - 6/30/2013' is shorter (90 days) and has only 1 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'Consolidated Statements of Cash Flows (USD $)' have maximum duration 365 days and at least 28 values. Shorter duration columns must have at least one fourth (7) as many values. Column '7/1/2013 - 9/30/2013' is shorter (91 days) and has only 1 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'Consolidated Statements of Cash Flows (USD $)' have maximum duration 365 days and at least 28 values. Shorter duration columns must have at least one fourth (7) as many values. Column '10/1/2013 - 12/31/2013' is shorter (91 days) and has only 2 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'Consolidated Statements of Cash Flows (USD $)' have maximum duration 365 days and at least 28 values. Shorter duration columns must have at least one fourth (7) as many values. Column '1/1/2014 - 3/31/2014' is shorter (89 days) and has only 2 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'Consolidated Statements of Cash Flows (USD $)' have maximum duration 365 days and at least 28 values. Shorter duration columns must have at least one fourth (7) as many values. Column '4/1/2014 - 6/30/2014' is shorter (90 days) and has only 1 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'Consolidated Statements of Cash Flows (USD $)' have maximum duration 365 days and at least 28 values. Shorter duration columns must have at least one fourth (7) as many values. Column '7/1/2014 - 9/30/2014' is shorter (91 days) and has only 1 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'Consolidated Statements of Cash Flows (USD $)' have maximum duration 365 days and at least 28 values. Shorter duration columns must have at least one fourth (7) as many values. Column '10/1/2014 - 12/31/2014' is shorter (91 days) and has only 2 values, so it is being removed.</Log>
    <Log type="Info">'Monetary' elements on report '100410 - Disclosure - Stock-Based Compensation - Additional Information (Detail)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '100440 - Disclosure - Major Customers, Partnerships and Strategic Alliances - Additional Information (Detail)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '100460 - Disclosure - Major Customers, Partnerships and Strategic Alliances - Agreement with Sigma-Aldrich Corporation - Additional Information (Detail)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '100470 - Disclosure - Major Customers, Partnerships and Strategic Alliances - Agreement with Dow AgroSciences in Plant Agriculture - Additional Information (Detail)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '100480 - Disclosure - Major Customers, Partnerships and Strategic Alliances - California Institute for Regenerative Medicine - Additional Information (Detail)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '100510 - Disclosure - Acquisition of Ceregene - Additional Information (Detail)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '100570 - Disclosure - Property and Equipment - Additional Information (Detail)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '100600 - Disclosure - Stockholders' Equity - Additional Information (Detail)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '100640 - Disclosure - Income Taxes - Additional Information (Detail)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">Process Flow-Through: 100010 - Statement - Consolidated Balance Sheets</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2012'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2011'</Log>
    <Log type="Info">Process Flow-Through: 100020 - Statement - Consolidated Balance Sheets (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 100030 - Statement - Consolidated Statements of Operations</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Dec. 31, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Sep. 30, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Jun. 30, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Mar. 31, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Dec. 31, 2013'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Sep. 30, 2013'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Jun. 30, 2013'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Mar. 31, 2013'</Log>
    <Log type="Info">Process Flow-Through: 100040 - Statement - Consolidated Statements of Comprehensive Loss</Log>
    <Log type="Info">Process Flow-Through: 100060 - Statement - Consolidated Statements of Cash Flows</Log>
  </Logs>
  <InputFiles>
    <File>sgmo-20141231.xml</File>
    <File>sgmo-20141231.xsd</File>
    <File>sgmo-20141231_cal.xml</File>
    <File>sgmo-20141231_def.xml</File>
    <File>sgmo-20141231_lab.xml</File>
    <File>sgmo-20141231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles />
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
