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, 2020
May 18, 2020
Sep. 30, 2019
Entity Registrant Name WESTELL TECHNOLOGIES INC    
Entity Central Index Key 0001002135    
Current Fiscal Year End Date --03-31    
Entity Filer Category Non-accelerated Filer    
Document Type 10-K    
Document Period End Date Mar. 31, 2020    
Document Fiscal Year Focus 2020    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Shell Company false    
Entity Emerging Growth Company false    
Entity Small Business true    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 14
Class A Common Stock [Member]      
Entity Common Stock, Shares Outstanding   12,324,775  
Class B Common Stock [Member]      
Entity Common Stock, Shares Outstanding   3,484,287