Annual report pursuant to Section 13 and 15(d)

Benefit Plans (Details)

v2.4.1.9
Benefit Plans (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended 9 Months Ended 1 Months Ended 9 Months Ended
Mar. 31, 2014
Mar. 31, 2015
Dec. 31, 2013
Mar. 31, 2014
Dec. 31, 2014
Westell [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent   100.00%us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
/ dei_LegalEntityAxis
= wstl_WestellMember 		     
Defined Contribution Plan, Employer Matching Contribution, Percent of Match   50.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
/ dei_LegalEntityAxis
= wstl_WestellMember 		     
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay   4.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
/ dei_LegalEntityAxis
= wstl_WestellMember 		     
Defined Contribution Plan, Employer Discretionary Contribution Amount $ 100us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
/ dei_LegalEntityAxis
= wstl_WestellMember 		$ 300us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
/ dei_LegalEntityAxis
= wstl_WestellMember 		     
Kentrox [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent     75.00%us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
/ dei_LegalEntityAxis
= wstl_KentroxMember 		   
Defined Contribution Plan, Employer Matching Contribution, Percent of Match     50.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
/ dei_LegalEntityAxis
= wstl_KentroxMember 		   
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay     6.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
/ dei_LegalEntityAxis
= wstl_KentroxMember 		   
Defined Contribution Plan, Employer Discretionary Contribution Amount     100us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
/ dei_LegalEntityAxis
= wstl_KentroxMember 		   
CSI [Member]          
Defined Benefit Plan Disclosure [Line Items]          
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent         100.00%us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
/ dei_LegalEntityAxis
= wstl_CSIMember
Defined Contribution Plan, Employer Discretionary Contribution Amount       $ 16us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
/ dei_LegalEntityAxis
= wstl_CSIMember 		$ 200us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
/ dei_LegalEntityAxis
= wstl_CSIMember
Deferred Compensation Arrangement with Individual, Employer Contribution         3.00%us-gaap_DeferredCompensationArrangementWithIndividualCashAwardsGrantedPercentage
/ dei_LegalEntityAxis
= wstl_CSIMember