XML 13 R1.htm IDEA: XBRL DOCUMENT v3.3.1.900
Document and Entity Information - shares
 9 Months Ended
Dec. 31, 2015
Jan. 25, 2016
Document And Entity Information    
Entity Registrant Name 8X8 INC /DE/  
Entity Central Index Key 0001023731  
Document Type 10-Q  
Document Period End Date Dec. 31, 2015  
Amendment Flag false  
Current Fiscal Year End Date --03-31  
Is Entity a Well-known Seasoned Issuer? Yes  
Is Entity a Voluntary Filer? No  
Is Entity's Reporting Status Current? Yes  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   88,456,638
Document Fiscal Period Focus Q3  
Document Fiscal Year Focus 2016