Quarterly report pursuant to Section 13 or 15(d)

Note 2 - Going Concern and Management's Plan (Details)

v2.4.1.9
Note 2 - Going Concern and Management's Plan (Details) (USD $)
0 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended 0 Months Ended
Mar. 13, 2014
Dec. 27, 2014
Dec. 28, 2013
Dec. 27, 2014
Dec. 28, 2013
Mar. 29, 2014
Mar. 14, 2014
Jun. 17, 2014
Jun. 28, 2014
Jun. 16, 2014
Note 2 - Going Concern and Management's Plan (Details) [Line Items]                    
Net Income (Loss) Attributable to Parent   $ 67,000us-gaap_NetIncomeLoss $ (718,000)us-gaap_NetIncomeLoss $ (283,000)us-gaap_NetIncomeLoss $ (2,476,000)us-gaap_NetIncomeLoss $ (3,742,000)us-gaap_NetIncomeLoss        
Retained Earnings (Accumulated Deficit)   (18,541,000)us-gaap_RetainedEarningsAccumulatedDeficit   (18,541,000)us-gaap_RetainedEarningsAccumulatedDeficit   (18,258,000)us-gaap_RetainedEarningsAccumulatedDeficit        
Proceeds from Lines of Credit       8,125,000us-gaap_ProceedsFromLinesOfCredit 136,000us-gaap_ProceedsFromLinesOfCredit          
Debt Instrument, Term 3 years                  
Proceeds from Issuance of Debt       500,000us-gaap_ProceedsFromIssuanceOfDebt            
Unbilled Receivables, Not Billable, Amount Expected to be Collected in Remainder of Fiscal Year                 6,200,000us-gaap_UnbilledReceivablesNotBillableAmountExpectedToBeCollectedInRemainderOfFiscalYear  
Unbilled Receivables, Not Billable, Amount Expected to be Collected in Next Twelve Months                 2,400,000us-gaap_UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedWithinOneYear  
Advance Payment Arrangements       1,400,000giga_AdvancePaymentArrangements   1,300,000giga_AdvancePaymentArrangements        
Scenario, Forecast [Member] | Microsource [Member] | New Order [Member]                    
Note 2 - Going Concern and Management's Plan (Details) [Line Items]                    
Unbilled Receivables, Not Billable, Amount Expected to be Collected after Next Twelve Months   10,000,000us-gaap_UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedAfterOneYear
/ us-gaap_ProductOrServiceAxis
= giga_NewOrderMember
/ us-gaap_StatementBusinessSegmentsAxis
= giga_MicrosourceMember
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
  10,000,000us-gaap_UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedAfterOneYear
/ us-gaap_ProductOrServiceAxis
= giga_NewOrderMember
/ us-gaap_StatementBusinessSegmentsAxis
= giga_MicrosourceMember
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
           
Microsource [Member]                    
Note 2 - Going Concern and Management's Plan (Details) [Line Items]                    
Net Income (Loss) Attributable to Parent   1,333,000us-gaap_NetIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= giga_MicrosourceMember
491,000us-gaap_NetIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= giga_MicrosourceMember
3,679,000us-gaap_NetIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= giga_MicrosourceMember
485,000us-gaap_NetIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= giga_MicrosourceMember
         
PFG Loan [Member]                    
Note 2 - Going Concern and Management's Plan (Details) [Line Items]                    
Debt Instrument, Term 3 years                  
Proceeds from Issuance of Debt 1,000,000us-gaap_ProceedsFromIssuanceOfDebt
/ us-gaap_DebtInstrumentAxis
= giga_PFGLoanMember
          1,000,000us-gaap_ProceedsFromIssuanceOfDebt
/ us-gaap_DebtInstrumentAxis
= giga_PFGLoanMember
     
Revolving Credit Facility [Member] | Partners For Growth IV, L.P. [Member]                    
Note 2 - Going Concern and Management's Plan (Details) [Line Items]                    
Line of Credit Facility, Maximum Borrowing Capacity                   500,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_LineOfCreditFacilityAxis
= giga_PartnersForGrowthIVLPMember
Proceeds from Lines of Credit             500,000us-gaap_ProceedsFromLinesOfCredit
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_LineOfCreditFacilityAxis
= giga_PartnersForGrowthIVLPMember
500,000us-gaap_ProceedsFromLinesOfCredit
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_LineOfCreditFacilityAxis
= giga_PartnersForGrowthIVLPMember
   
Line of Credit Facility, Maximum Borrowing Capacity, Additional       500,000giga_LineOfCreditFacilityMaximumBorrowingCapacityAdditional
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_LineOfCreditFacilityAxis
= giga_PartnersForGrowthIVLPMember
           
Silicon Valley Bank [Member]                    
Note 2 - Going Concern and Management's Plan (Details) [Line Items]                    
Long-term Line of Credit   1,600,000us-gaap_LineOfCredit
/ us-gaap_LineOfCreditFacilityAxis
= giga_SiliconValleyBankMember
  1,600,000us-gaap_LineOfCredit
/ us-gaap_LineOfCreditFacilityAxis
= giga_SiliconValleyBankMember
           
Line of Credit Facility, Maximum Borrowing Capacity   $ 3,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
/ us-gaap_LineOfCreditFacilityAxis
= giga_SiliconValleyBankMember
  $ 3,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
/ us-gaap_LineOfCreditFacilityAxis
= giga_SiliconValleyBankMember