Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Mar. 31, 2015
May. 14, 2015
Sep. 30, 2014
Entity Registrant Name WESTELL TECHNOLOGIES INC    
Entity Central Index Key 0001002135    
Current Fiscal Year End Date --03-31    
Document Type 10-K/A    
Document Period End Date Mar. 31, 2015    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Amendment Flag true    
Amendment Description This Amendment No. 1 on Form 10-K/A ("Amendment No. 1") amends the Annual Report on Form 10-K of Westell Technologies, Inc. (the “Company”) for the fiscal year ended March 31, 2015, as originally filed with the Securities and Exchange Commission (the “SEC”) on May 22, 2015 (the “Original Filing”). This Amendment No. 1 amends the Original Filing to correct an error related to a previously unidentified pre-acquisition liability, as more fully described in Note 1 to the Consolidated Financial Statements contained in this Amendment No. 1.    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Accelerated Filer    
Entity Public Float     $ 79
Class A Common Stock [Member]      
Entity Common Stock, Shares Outstanding   46,892,935  
Class B Common Stock [Member]      
Entity Common Stock, Shares Outstanding   13,937,151