XML 13 R1.htm IDEA: XBRL DOCUMENT v3.6.0.2
Document And Entity Information - USD ($)
 12 Months Ended
Sep. 30, 2016
Dec. 26, 2016
Mar. 31, 2016
Document and Entity Information [Abstract]      
Entity Registrant Name CSP INC /MA/    
Document Type 10-K    
Current Fiscal Year End Date --09-30    
Entity Common Stock, Shares Outstanding   3,820,737  
Entity Public Float     $ 28,944,452
Amendment Flag false    
Entity Central Index Key 0000356037    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Smaller Reporting Company    
Entity Well-known Seasoned Issuer No    
Document Period End Date Sep. 30, 2016    
Document Fiscal Year Focus 2016    
Document Fiscal Period Focus FY