Annual report pursuant to Section 13 and 15(d)

Income Taxes (Details Textual)

v2.4.1.9
Income Taxes (Details Textual) (USD $)
 3 Months Ended 12 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2015
Mar. 31, 2014
Mar. 31, 2013
Mar. 31, 2022
Mar. 31, 2023
Income Tax Contingency [Line Items]                          
Unrecognized Tax Benefits that Would Impact Effective Tax Rate $ 1,500,000us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate       $ 1,300,000us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate       $ 1,500,000us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate $ 1,300,000us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate      
Income Tax Expense (Benefit) (31,000)us-gaap_IncomeTaxExpenseBenefit (72,000)us-gaap_IncomeTaxExpenseBenefit (69,000)us-gaap_IncomeTaxExpenseBenefit (29,000)us-gaap_IncomeTaxExpenseBenefit (8,585,000)us-gaap_IncomeTaxExpenseBenefit 38,000us-gaap_IncomeTaxExpenseBenefit 68,000us-gaap_IncomeTaxExpenseBenefit 19,000us-gaap_IncomeTaxExpenseBenefit (201,000)us-gaap_IncomeTaxExpenseBenefit (8,460,000)us-gaap_IncomeTaxExpenseBenefit [1] 29,392,000us-gaap_IncomeTaxExpenseBenefit    
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent         8,800,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent         8,800,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent      
IncomeTaxExpenseBenefitExcludingValuationAllowanceReversalAcquiredDeferredTaxLiability                   400,000wstl_IncomeTaxExpenseBenefitExcludingValuationAllowanceReversalAcquiredDeferredTaxLiability      
Valuation Allowance, Deferred Tax Asset, Change in Amount                     34,000,000us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount    
Tax Credit Carryforward, Amount 1,500,000us-gaap_TaxCreditCarryforwardAmount               1,500,000us-gaap_TaxCreditCarryforwardAmount        
Deferred Tax Assets, Valuation Allowance 39,117,000us-gaap_DeferredTaxAssetsValuationAllowance       28,864,000us-gaap_DeferredTaxAssetsValuationAllowance       39,117,000us-gaap_DeferredTaxAssetsValuationAllowance 28,864,000us-gaap_DeferredTaxAssetsValuationAllowance      
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense                 6,000us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense 3,000us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense 12,000us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense    
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued 1,000us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued       1,000us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued       1,000us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued 1,000us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued      
Federal [Member]                          
Income Tax Contingency [Line Items]                          
Operating Loss Carryforwards 30,900,000us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= wstl_FederalMember 		              30,900,000us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= wstl_FederalMember 		       
State and Local Jurisdiction [Member]                          
Income Tax Contingency [Line Items]                          
Income Tax Expense (Benefit)                 (118,000)us-gaap_IncomeTaxExpenseBenefit
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember 		(1,279,000)us-gaap_IncomeTaxExpenseBenefit
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember 		4,799,000us-gaap_IncomeTaxExpenseBenefit
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember 		   
Operating Loss Carryforwards $ 6,000,000us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember 		              $ 6,000,000us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember 		       
Subsequent Event [Member]                          
Income Tax Contingency [Line Items]                          
Other Tax Carryforward, Expiration Dates                       Mar. 31, 2022  
Subsequent Event [Member] | Minimum [Member] | Federal [Member]                          
Income Tax Contingency [Line Items]                          
Operating Loss Carryforwards, Expiration Dates                         Mar. 31, 2023
Subsequent Event [Member] | Minimum [Member] | State and Local Jurisdiction [Member]                          
Income Tax Contingency [Line Items]                          
Operating Loss Carryforwards, Expiration Dates                         Mar. 31, 2016
[1] Certain amounts have been adjusted to reflect measurement period adjustments related to the CSI acquisition (see Note 2).