3.20.1 html 255 486 1 false 87 0 false 10 false false R1.htm 00090 - Document - Document and Entity Information Sheet http://gsitechnology.com/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 00100 - Statement - CONSOLIDATED BALANCE SHEETS Sheet http://gsitechnology.com/role/StatementConsolidatedBalanceSheets CONSOLIDATED BALANCE SHEETS Statements 2 false false R3.htm 00105 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://gsitechnology.com/role/StatementConsolidatedBalanceSheetsParenthetical CONSOLIDATED BALANCE SHEETS (Parenthetical) Statements 3 false false R4.htm 00200 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS Sheet http://gsitechnology.com/role/StatementConsolidatedStatementsOfOperations CONSOLIDATED STATEMENTS OF OPERATIONS Statements 4 false false R5.htm 00300 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) Sheet http://gsitechnology.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) Statements 5 false false R6.htm 00400 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY Sheet http://gsitechnology.com/role/StatementConsolidatedStatementsOfStockholdersEquity CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY Statements 6 false false R7.htm 00500 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://gsitechnology.com/role/StatementConsolidatedStatementsOfCashFlows CONSOLIDATED STATEMENTS OF CASH FLOWS Statements 7 false false R8.htm 10101 - Disclosure - 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Sheet http://gsitechnology.com/role/Disclosure1CompanyAndSummaryOfSignificantAccountingPolicies 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Notes 8 false false R9.htm 10201 - Disclosure - 2. REVENUE RECOGNITION Sheet http://gsitechnology.com/role/Disclosure2RevenueRecognition 2. REVENUE RECOGNITION Notes 9 false false R10.htm 10301 - Disclosure - 3. NET INCOME (LOSS) PER COMMON SHARE Sheet http://gsitechnology.com/role/Disclosure3NetIncomeLossPerCommonShare 3. NET INCOME (LOSS) PER COMMON SHARE Notes 10 false false R11.htm 10401 - Disclosure - 4. BALANCE SHEET DETAIL Sheet http://gsitechnology.com/role/Disclosure4BalanceSheetDetail 4. BALANCE SHEET DETAIL Notes 11 false false R12.htm 10501 - Disclosure - 5. GOODWILL Sheet http://gsitechnology.com/role/Disclosure5Goodwill 5. GOODWILL Notes 12 false false R13.htm 10601 - Disclosure - 6. INCOME TAXES Sheet http://gsitechnology.com/role/Disclosure6IncomeTaxes 6. INCOME TAXES Notes 13 false false R14.htm 10701 - Disclosure - 7. FINANCIAL INSTRUMENTS Sheet http://gsitechnology.com/role/Disclosure7FinancialInstruments 7. FINANCIAL INSTRUMENTS Notes 14 false false R15.htm 10801 - Disclosure - 8. LEASES Sheet http://gsitechnology.com/role/Disclosure8Leases 8. LEASES Notes 15 false false R16.htm 10901 - Disclosure - 9. COMMITMENTS AND CONTINGENCIES Sheet http://gsitechnology.com/role/Disclosure9CommitmentsAndContingencies 9. COMMITMENTS AND CONTINGENCIES Notes 16 false false R17.htm 11001 - Disclosure - 10. COMMON STOCK Sheet http://gsitechnology.com/role/Disclosure10CommonStock 10. COMMON STOCK Notes 17 false false R18.htm 11101 - Disclosure - 11. STOCK-BASED COMPENSATION Sheet http://gsitechnology.com/role/Disclosure11StockBasedCompensation 11. STOCK-BASED COMPENSATION Notes 18 false false R19.htm 11201 - Disclosure - 12. RELATED PARTY TRANSACTION Sheet http://gsitechnology.com/role/Disclosure12RelatedPartyTransaction 12. RELATED PARTY TRANSACTION Notes 19 false false R20.htm 11301 - Disclosure - 13. SEGMENT AND GEOGRAPHIC INFORMATION Sheet http://gsitechnology.com/role/Disclosure13SegmentAndGeographicInformation 13. SEGMENT AND GEOGRAPHIC INFORMATION Notes 20 false false R21.htm 11401 - Disclosure - 14. ACQUISITION Sheet http://gsitechnology.com/role/Disclosure14Acquisition 14. ACQUISITION Notes 21 false false R22.htm 11501 - Disclosure - 15. EMPLOYEE BENEFIT PLANS Sheet http://gsitechnology.com/role/Disclosure15EmployeeBenefitPlans 15. EMPLOYEE BENEFIT PLANS Notes 22 false false R23.htm 11601 - Disclosure - 16. QUARTERLY FINANCIAL DATA Sheet http://gsitechnology.com/role/Disclosure16QuarterlyFinancialData 16. QUARTERLY FINANCIAL DATA Notes 23 false false R24.htm 20102 - Disclosure - 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) Sheet http://gsitechnology.com/role/Disclosure1CompanyAndSummaryOfSignificantAccountingPoliciesPolicies 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) Policies 24 false false R25.htm 30103 - Disclosure - 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) Sheet http://gsitechnology.com/role/Disclosure1CompanyAndSummaryOfSignificantAccountingPoliciesTables 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) Tables http://gsitechnology.com/role/Disclosure1CompanyAndSummaryOfSignificantAccountingPolicies 25 false false R26.htm 30203 - Disclosure - 2. REVENUE RECOGNITION (Tables) Sheet http://gsitechnology.com/role/Disclosure2RevenueRecognitionTables 2. REVENUE RECOGNITION (Tables) Tables http://gsitechnology.com/role/Disclosure2RevenueRecognition 26 false false R27.htm 30303 - Disclosure - 3. NET INCOME (LOSS) PER COMMON SHARE (Tables) Sheet http://gsitechnology.com/role/Disclosure3NetIncomeLossPerCommonShareTables 3. NET INCOME (LOSS) PER COMMON SHARE (Tables) Tables http://gsitechnology.com/role/Disclosure3NetIncomeLossPerCommonShare 27 false false R28.htm 30403 - Disclosure - 4. BALANCE SHEET DETAIL (Tables) Sheet http://gsitechnology.com/role/Disclosure4BalanceSheetDetailTables 4. BALANCE SHEET DETAIL (Tables) Tables http://gsitechnology.com/role/Disclosure4BalanceSheetDetail 28 false false R29.htm 30603 - Disclosure - 6. INCOME TAXES (Tables) Sheet http://gsitechnology.com/role/Disclosure6IncomeTaxesTables 6. INCOME TAXES (Tables) Tables http://gsitechnology.com/role/Disclosure6IncomeTaxes 29 false false R30.htm 30703 - Disclosure - 7. FINANCIAL INSTRUMENTS (Tables) Sheet http://gsitechnology.com/role/Disclosure7FinancialInstrumentsTables 7. FINANCIAL INSTRUMENTS (Tables) Tables http://gsitechnology.com/role/Disclosure7FinancialInstruments 30 false false R31.htm 30803 - Disclosure - 8. LEASES (Tables) Sheet http://gsitechnology.com/role/Disclosure8LeasesTables 8. LEASES (Tables) Tables http://gsitechnology.com/role/Disclosure8Leases 31 false false R32.htm 31103 - Disclosure - 11. STOCK-BASED COMPENSATION (Tables) Sheet http://gsitechnology.com/role/Disclosure11StockBasedCompensationTables 11. STOCK-BASED COMPENSATION (Tables) Tables http://gsitechnology.com/role/Disclosure11StockBasedCompensation 32 false false R33.htm 31303 - Disclosure - 13. SEGMENT AND GEOGRAPHIC INFORMATION (Tables) Sheet http://gsitechnology.com/role/Disclosure13SegmentAndGeographicInformationTables 13. SEGMENT AND GEOGRAPHIC INFORMATION (Tables) Tables http://gsitechnology.com/role/Disclosure13SegmentAndGeographicInformation 33 false false R34.htm 31603 - Disclosure - 16. QUARTERLY FINANCIAL DATA (Tables) Sheet http://gsitechnology.com/role/Disclosure16QuarterlyFinancialDataTables 16. QUARTERLY FINANCIAL DATA (Tables) Tables http://gsitechnology.com/role/Disclosure16QuarterlyFinancialData 34 false false R35.htm 40101 - Disclosure - 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) Sheet http://gsitechnology.com/role/Disclosure1CompanyAndSummaryOfSignificantAccountingPoliciesDetails 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) Details http://gsitechnology.com/role/Disclosure1CompanyAndSummaryOfSignificantAccountingPoliciesTables 35 false false R36.htm 40102 - Disclosure - 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - PP&E (Details) Sheet http://gsitechnology.com/role/Disclosure1CompanyAndSummaryOfSignificantAccountingPoliciesPpEDetails 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - PP&E (Details) Details http://gsitechnology.com/role/Disclosure1CompanyAndSummaryOfSignificantAccountingPoliciesTables 36 false false R37.htm 40103 - Disclosure - 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Recent accounting pronouncements (Details) Sheet http://gsitechnology.com/role/Disclosure1CompanyAndSummaryOfSignificantAccountingPoliciesRecentAccountingPronouncementsDetails 1. THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Recent accounting pronouncements (Details) Details 37 false false R38.htm 40201 - Disclosure - 2. REVENUE RECOGNITION (Details) Sheet http://gsitechnology.com/role/Disclosure2RevenueRecognitionDetails 2. REVENUE RECOGNITION (Details) Details http://gsitechnology.com/role/Disclosure2RevenueRecognitionTables 38 false false R39.htm 40202 - Disclosure - 2. REVENUE RECOGNITION - Revenue disaggregated (Details) Sheet http://gsitechnology.com/role/Disclosure2RevenueRecognitionRevenueDisaggregatedDetails 2. REVENUE RECOGNITION - Revenue disaggregated (Details) Details 39 false false R40.htm 40301 - Disclosure - 3. NET INCOME (LOSS) PER COMMON SHARE (Details) Sheet http://gsitechnology.com/role/Disclosure3NetIncomeLossPerCommonShareDetails 3. NET INCOME (LOSS) PER COMMON SHARE (Details) Details http://gsitechnology.com/role/Disclosure3NetIncomeLossPerCommonShareTables 40 false false R41.htm 40302 - Disclosure - 3. NET INCOME (LOSS) PER COMMON SHARE - Shares underlying options (Details) Sheet http://gsitechnology.com/role/Disclosure3NetIncomeLossPerCommonShareSharesUnderlyingOptionsDetails 3. NET INCOME (LOSS) PER COMMON SHARE - Shares underlying options (Details) Details http://gsitechnology.com/role/Disclosure3NetIncomeLossPerCommonShareTables 41 false false R42.htm 40401 - Disclosure - 4. BALANCE SHEET DETAIL - Inventories (Details) Sheet http://gsitechnology.com/role/Disclosure4BalanceSheetDetailInventoriesDetails 4. BALANCE SHEET DETAIL - Inventories (Details) Details 42 false false R43.htm 40402 - Disclosure - 4. BALANCE SHEET DETAIL - Accounts receivable, net (Details) Sheet http://gsitechnology.com/role/Disclosure4BalanceSheetDetailAccountsReceivableNetDetails 4. BALANCE SHEET DETAIL - Accounts receivable, net (Details) Details 43 false false R44.htm 40403 - Disclosure - 4. BALANCE SHEET DETAIL - Prepaid expenses and other current assets (Details) Sheet http://gsitechnology.com/role/Disclosure4BalanceSheetDetailPrepaidExpensesAndOtherCurrentAssetsDetails 4. BALANCE SHEET DETAIL - Prepaid expenses and other current assets (Details) Details 44 false false R45.htm 40404 - Disclosure - 4. BALANCE SHEET DETAIL - Property and equipment, net (Details) Sheet http://gsitechnology.com/role/Disclosure4BalanceSheetDetailPropertyAndEquipmentNetDetails 4. BALANCE SHEET DETAIL - Property and equipment, net (Details) Details 45 false false R46.htm 40405 - Disclosure - 4. BALANCE SHEET DETAIL - Other assets (Details) Sheet http://gsitechnology.com/role/Disclosure4BalanceSheetDetailOtherAssetsDetails 4. BALANCE SHEET DETAIL - Other assets (Details) Details 46 false false R47.htm 40406 - Disclosure - 4. BALANCE SHEET DETAIL - Intangible assets (Details) Sheet http://gsitechnology.com/role/Disclosure4BalanceSheetDetailIntangibleAssetsDetails 4. BALANCE SHEET DETAIL - Intangible assets (Details) Details 47 false false R48.htm 40407 - Disclosure - 4. BALANCE SHEET DETAIL - Future amortization (Details) Sheet http://gsitechnology.com/role/Disclosure4BalanceSheetDetailFutureAmortizationDetails 4. BALANCE SHEET DETAIL - Future amortization (Details) Details 48 false false R49.htm 40408 - Disclosure - 4. BALANCE SHEET DETAIL - Accrued expenses and other liabilities (Details) Sheet http://gsitechnology.com/role/Disclosure4BalanceSheetDetailAccruedExpensesAndOtherLiabilitiesDetails 4. BALANCE SHEET DETAIL - Accrued expenses and other liabilities (Details) Details 49 false false R50.htm 40501 - Disclosure - 5. GOODWILL (Details) Sheet http://gsitechnology.com/role/Disclosure5GoodwillDetails 5. GOODWILL (Details) Details http://gsitechnology.com/role/Disclosure5Goodwill 50 false false R51.htm 40601 - Disclosure - 6. INCOME TAXES - Provision for income taxes (Details) Sheet http://gsitechnology.com/role/Disclosure6IncomeTaxesProvisionForIncomeTaxesDetails 6. INCOME TAXES - Provision for income taxes (Details) Details 51 false false R52.htm 40602 - Disclosure - 6. INCOME TAXES - Statutory income tax (Details) Sheet http://gsitechnology.com/role/Disclosure6IncomeTaxesStatutoryIncomeTaxDetails 6. INCOME TAXES - Statutory income tax (Details) Details 52 false false R53.htm 40603 - Disclosure - 6. INCOME TAXES - Deferred tax assets and liabilities (Details) Sheet http://gsitechnology.com/role/Disclosure6IncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails 6. INCOME TAXES - Deferred tax assets and liabilities (Details) Details 53 false false R54.htm 40604 - Disclosure - 6. INCOME TAXES - Unrecognized tax benefits (Details) Sheet http://gsitechnology.com/role/Disclosure6IncomeTaxesUnrecognizedTaxBenefitsDetails 6. INCOME TAXES - Unrecognized tax benefits (Details) Details 54 false false R55.htm 40605 - Disclosure - 6. INCOME TAXES - Tax Cuts and Jobs Act (Details) Sheet http://gsitechnology.com/role/Disclosure6IncomeTaxesTaxCutsAndJobsActDetails 6. INCOME TAXES - Tax Cuts and Jobs Act (Details) Details 55 false false R56.htm 40701 - Disclosure - 7. FINANCIAL INSTRUMENTS (Details) Sheet http://gsitechnology.com/role/Disclosure7FinancialInstrumentsDetails 7. FINANCIAL INSTRUMENTS (Details) Details http://gsitechnology.com/role/Disclosure7FinancialInstrumentsTables 56 false false R57.htm 40702 - Disclosure - 7. FINANCIAL INSTRUMENTS - Change in contingent consideration (Details) Sheet http://gsitechnology.com/role/Disclosure7FinancialInstrumentsChangeInContingentConsiderationDetails 7. FINANCIAL INSTRUMENTS - Change in contingent consideration (Details) Details 57 false false R58.htm 40703 - Disclosure - 7. FINANCIAL INSTRUMENTS - Available-for-sale investments (Details) Sheet http://gsitechnology.com/role/Disclosure7FinancialInstrumentsAvailableForSaleInvestmentsDetails 7. FINANCIAL INSTRUMENTS - Available-for-sale investments (Details) Details 58 false false R59.htm 40704 - Disclosure - 7. FINANCIAL INSTRUMENTS - Unrealized losses and fair value (Details) Sheet http://gsitechnology.com/role/Disclosure7FinancialInstrumentsUnrealizedLossesAndFairValueDetails 7. FINANCIAL INSTRUMENTS - Unrealized losses and fair value (Details) Details 59 false false R60.htm 40705 - Disclosure - 7. FINANCIAL INSTRUMENTS - Other information (Details) Sheet http://gsitechnology.com/role/Disclosure7FinancialInstrumentsOtherInformationDetails 7. FINANCIAL INSTRUMENTS - Other information (Details) Details 60 false false R61.htm 40706 - Disclosure - 7. FINANCIAL INSTRUMENTS - Contractual maturities (Details) Sheet http://gsitechnology.com/role/Disclosure7FinancialInstrumentsContractualMaturitiesDetails 7. FINANCIAL INSTRUMENTS - Contractual maturities (Details) Details 61 false false R62.htm 40801 - Disclosure - 8. LEASES - Operating leases (Details) Sheet http://gsitechnology.com/role/Disclosure8LeasesOperatingLeasesDetails 8. LEASES - Operating leases (Details) Details 62 false false R63.htm 40802 - Disclosure - 8. LEASES - Lease costs (Details) Sheet http://gsitechnology.com/role/Disclosure8LeasesLeaseCostsDetails 8. LEASES - Lease costs (Details) Details 63 false false R64.htm 40803 - Disclosure - 8. LEASES - Other information (Details) Sheet http://gsitechnology.com/role/Disclosure8LeasesOtherInformationDetails 8. LEASES - Other information (Details) Details 64 false false R65.htm 40804 - Disclosure - 8. LEASES - Maturity of lease liabilities (Details) Sheet http://gsitechnology.com/role/Disclosure8LeasesMaturityOfLeaseLiabilitiesDetails 8. LEASES - Maturity of lease liabilities (Details) Details 65 false false R66.htm 40902 - Disclosure - 9. COMMITMENTS AND CONTINGENCIES - Product warranties (Details) Sheet http://gsitechnology.com/role/Disclosure9CommitmentsAndContingenciesProductWarrantiesDetails 9. COMMITMENTS AND CONTINGENCIES - Product warranties (Details) Details 66 false false R67.htm 40903 - Disclosure - 10. COMMON STOCK - Repurchases (Details) Sheet http://gsitechnology.com/role/Disclosure10CommonStockRepurchasesDetails 10. COMMON STOCK - Repurchases (Details) Details 67 false false R68.htm 41001 - Disclosure - 10. COMMON STOCK (Details) Sheet http://gsitechnology.com/role/Disclosure10CommonStockDetails 10. COMMON STOCK (Details) Details http://gsitechnology.com/role/Disclosure10CommonStock 68 false false R69.htm 41002 - Disclosure - 10. COMMON STOCK - Dutch auction (Details) Sheet http://gsitechnology.com/role/Disclosure10CommonStockDutchAuctionDetails 10. COMMON STOCK - Dutch auction (Details) Details 69 false false R70.htm 41101 - Disclosure - 11. STOCK-BASED COMPENSATION (Details) Sheet http://gsitechnology.com/role/Disclosure11StockBasedCompensationDetails 11. STOCK-BASED COMPENSATION (Details) Details http://gsitechnology.com/role/Disclosure11StockBasedCompensationTables 70 false false R71.htm 41102 - Disclosure - 11. STOCK-BASED COMPENSATION - Stock option activities (Details) Sheet http://gsitechnology.com/role/Disclosure11StockBasedCompensationStockOptionActivitiesDetails 11. STOCK-BASED COMPENSATION - Stock option activities (Details) Details 71 false false R72.htm 41103 - Disclosure - 11. STOCK-BASED COMPENSATION - Options outstanding by exercise price (Details) Sheet http://gsitechnology.com/role/Disclosure11StockBasedCompensationOptionsOutstandingByExercisePriceDetails 11. STOCK-BASED COMPENSATION - Options outstanding by exercise price (Details) Details 72 false false R73.htm 41104 - Disclosure - 11. STOCK-BASED COMPENSATION - Stock-based compensation expense (Details) Sheet http://gsitechnology.com/role/Disclosure11StockBasedCompensationStockBasedCompensationExpenseDetails 11. STOCK-BASED COMPENSATION - Stock-based compensation expense (Details) Details 73 false false R74.htm 41105 - Disclosure - 11. STOCK-BASED COMPENSATION - Weighted average assumptions (Details) Sheet http://gsitechnology.com/role/Disclosure11StockBasedCompensationWeightedAverageAssumptionsDetails 11. STOCK-BASED COMPENSATION - Weighted average assumptions (Details) Details 74 false false R75.htm 41201 - Disclosure - 12. RELATED PARTY TRANSACTION (Details) Sheet http://gsitechnology.com/role/Disclosure12RelatedPartyTransactionDetails 12. RELATED PARTY TRANSACTION (Details) Details http://gsitechnology.com/role/Disclosure12RelatedPartyTransaction 75 false false R76.htm 41301 - Disclosure - 13. SEGMENT AND GEOGRAPHIC INFORMATION - Revenue (Details) Sheet http://gsitechnology.com/role/Disclosure13SegmentAndGeographicInformationRevenueDetails 13. SEGMENT AND GEOGRAPHIC INFORMATION - Revenue (Details) Details 76 false false R77.htm 41302 - Disclosure - 13. SEGMENT AND GEOGRAPHIC INFORMATION - Long-lived assets (Details) Sheet http://gsitechnology.com/role/Disclosure13SegmentAndGeographicInformationLongLivedAssetsDetails 13. SEGMENT AND GEOGRAPHIC INFORMATION - Long-lived assets (Details) Details 77 false false R78.htm 41401 - Disclosure - 14. ACQUISITION (Details) Sheet http://gsitechnology.com/role/Disclosure14AcquisitionDetails 14. ACQUISITION (Details) Details http://gsitechnology.com/role/Disclosure14Acquisition 78 false false R79.htm 41501 - Disclosure - 15. EMPLOYEE BENEFIT PLANS (Details) Sheet http://gsitechnology.com/role/Disclosure15EmployeeBenefitPlansDetails 15. EMPLOYEE BENEFIT PLANS (Details) Details http://gsitechnology.com/role/Disclosure15EmployeeBenefitPlans 79 false false R80.htm 41601 - Disclosure - 16. QUARTERLY FINANCIAL DATA (Unaudited) (Details) Sheet http://gsitechnology.com/role/Disclosure16QuarterlyFinancialDataUnauditedDetails 16. QUARTERLY FINANCIAL DATA (Unaudited) (Details) Details http://gsitechnology.com/role/Disclosure16QuarterlyFinancialDataTables 80 false false All Reports Book All Reports gsit-20200331.xml gsit-20200331.xsd gsit-20200331_cal.xml gsit-20200331_def.xml gsit-20200331_lab.xml gsit-20200331_pre.xml http://xbrl.sec.gov/country/2017-01-31 http://xbrl.sec.gov/dei/2019-01-31 http://fasb.org/srt/2019-01-31 http://fasb.org/us-gaap/2019-01-31 true true