XML 11 R1.htm IDEA: XBRL DOCUMENT v3.8.0.1
Document and Entity Information - shares
 3 Months Ended
Apr. 30, 2018
May 31, 2018
Document And Entity Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Apr. 30, 2018  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Trading Symbol BOX  
Entity Registrant Name BOX INC  
Entity Central Index Key 0001372612  
Current Fiscal Year End Date --01-31  
Entity Filer Category Large Accelerated Filer  
Class A Common Stock    
Document And Entity Information [Line Items]    
Entity Common Stock, Shares Outstanding   131,764,530
Class B Common Stock    
Document And Entity Information [Line Items]    
Entity Common Stock, Shares Outstanding   8,383,930