v3.6.0.2
Document And Entity Information - shares
3 Months Ended
Dec. 31, 2016
Feb. 10, 2017
Document And Entity Information [Abstract]    
Entity Registrant Name Oncobiologics, Inc.  
Entity Central Index Key 0001649989  
Trading Symbol ons  
Current Fiscal Year End Date --09-30  
Entity Filer Category Smaller Reporting Company  
Entity Common Stock, Shares Outstanding   23,631,448
Document Type 10-Q  
Document Period End Date Dec. 31, 2016  
Amendment Flag false  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q1