Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

Document and Entity Information - shares
9 Months Ended
Dec. 31, 2018
Sep. 28, 2018
Document and Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Entity Interactive Data Current Yes  
Document Period End Date Dec. 31, 2018  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Entity Registrant Name QUANTUM CORP /DE/  
Entity Central Index Key 0000709283  
Trading Symbol QMCO  
Current Fiscal Year End Date --03-31  
Entity Filer Category Non-accelerated Filer  
Entity Current Reporting Status Yes  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Address, State or Province CA  
Entity Common Stock, Shares Outstanding   35,551,570
Title of 12(b) Security Common Stock  
Security Exchange Name NONE