Annual report pursuant to Section 13 and 15(d)

Basis of Presentation (Details Textual)

v2.4.1.9
Basis of Presentation (Details Textual) (USD $)
 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2015
Mar. 31, 2014
Mar. 31, 2013
Dec. 31, 2012
Mar. 31, 2012
Apr. 02, 2013
Mar. 02, 2014
Apr. 15, 2011
Dec. 31, 2011
Business Acquisition [Line Items]                            
Selling and Marketing Expense           $ 12,407,000us-gaap_SellingAndMarketingExpense $ 13,304,000us-gaap_SellingAndMarketingExpense [1] $ 6,783,000us-gaap_SellingAndMarketingExpense [1]            
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax           227,000us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax (45,000)us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax (2,309,000)us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax            
Income (loss) from discontinued operations, net of tax benefit (expense) of $(88), $0 and $813 for fiscal years 2015, 2014 and 2013, respectively 139,000us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax (6,000)us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax (29,000)us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax 4,000us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax (14,000)us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax 139,000us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax (45,000)us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax (1,496,000)us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax            
Cost of revenue           57,317,000us-gaap_CostOfGoodsAndServicesSold 61,612,000us-gaap_CostOfGoodsAndServicesSold [1],[2] 26,192,000us-gaap_CostOfGoodsAndServicesSold [1]            
CostofRevenueAdjustmentUsingPreviousAccountingGuidance           (900,000)wstl_CostofRevenueAdjustmentUsingPreviousAccountingGuidance                
Kentrox [Member]                            
Business Acquisition [Line Items]                            
Business Acquisition, Percentage of Voting Interests Acquired                     100.00%us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
/ us-gaap_BusinessAcquisitionAxis
= wstl_KentroxMember 		     
CSI [Member]                            
Business Acquisition [Line Items]                            
Business Acquisition, Percentage of Voting Interests Acquired                       100.00%us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
/ us-gaap_BusinessAcquisitionAxis
= wstl_CSIMember 		   
CNS [Member]                            
Business Acquisition [Line Items]                            
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax             (45,000)us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_CnsMember 		(951,000)us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_CnsMember 		           
Proceeds from CNS asset sale                   36,700,000us-gaap_ProceedsFromSalesOfAssetsInvestingActivities
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_CnsMember 		       
Escrow deposit made                         3,400,000us-gaap_EscrowDeposit
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_CnsMember 		 
Litigation Settlement, Amount                 900,000us-gaap_LitigationSettlementAmount
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_CnsMember 		         
Loss Contingency Accrual, at Carrying Value                   400,000us-gaap_LossContingencyAccrualAtCarryingValue
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_CnsMember 		       
Additional expense related to CNS claim               500,000wstl_AdditionalExpensesOnClaims
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_CnsMember 		           
ConferencePlus [Member]                            
Business Acquisition [Line Items]                            
Sale of conference plus                           40,300,000wstl_BusinessSegmentSaleConsideration
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_ConferenceplusMember
Loss Contingency, Loss in Period               1,500,000us-gaap_LossContingencyLossInPeriod
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_ConferenceplusMember 		           
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax               (1,358,000)us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_ConferenceplusMember 		           
Escrow Deposit Released             2,500,000wstl_EscrowDepositReleased
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_ConferenceplusMember 		1,600,000wstl_EscrowDepositReleased
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_ConferenceplusMember 		           
Escrow deposit made                           4,100,000us-gaap_EscrowDeposit
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_ConferenceplusMember
Westell [Member] | CNS [Member]                            
Business Acquisition [Line Items]                            
Escrow Deposit Released               2,600,000wstl_EscrowDepositReleased
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_CnsMember
/ dei_LegalEntityAxis
= wstl_WestellMember 		           
Westell [Member] | ConferencePlus [Member]                            
Business Acquisition [Line Items]                            
Escrow Deposit Released             3,000,000wstl_EscrowDepositReleased
/ dei_LegalEntityAxis
= wstl_WestellMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= wstl_ConferenceplusMember 		             
Arkadin [Member] | ConferencePlus [Member]                            
Business Acquisition [Line Items]                            
Escrow Deposit Released             1,100,000wstl_EscrowDepositReleased
/ dei_LegalEntityAxis
= wstl_ArkadinMemberMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= wstl_ConferenceplusMember 		             
Netgear [Member] | CNS [Member]                            
Business Acquisition [Line Items]                            
Escrow Deposit Released               900,000wstl_EscrowDepositReleased
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= wstl_CnsMember
/ dei_LegalEntityAxis
= wstl_NetgearMember 		           
Restatement Adjustment [Member]                            
Business Acquisition [Line Items]                            
Selling and Marketing Expense             (1,359,000)us-gaap_SellingAndMarketingExpense
/ us-gaap_StatementScenarioAxis
= us-gaap_RestatementAdjustmentMember 		[3] (709,000)us-gaap_SellingAndMarketingExpense
/ us-gaap_StatementScenarioAxis
= us-gaap_RestatementAdjustmentMember 		[3]            
Cost of revenue             1,359,000us-gaap_CostOfGoodsAndServicesSold
/ us-gaap_StatementScenarioAxis
= us-gaap_RestatementAdjustmentMember 		[3] 709,000us-gaap_CostOfGoodsAndServicesSold
/ us-gaap_StatementScenarioAxis
= us-gaap_RestatementAdjustmentMember 		[3]            
Restatement Adjustment [Member] | CSI [Member]                            
Business Acquisition [Line Items]                            
Cost of revenue             $ 138,000us-gaap_CostOfGoodsAndServicesSold
/ us-gaap_BusinessAcquisitionAxis
= wstl_CSIMember
/ us-gaap_StatementScenarioAxis
= us-gaap_RestatementAdjustmentMember 		[2]              
[1] Certain amounts have been reclassified to reflect a change in accounting principle (see Note 1).
[2] Certain amounts have been adjusted to reflect measurement period adjustments related to the CSI acquisition (see Note 2).
[3] See Voluntary Change in Accounting Principle above