XML 18 R1.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Document and Entity Information - shares
 3 Months Ended
Dec. 31, 2019
Jan. 31, 2020
Document and Entity Information    
Entity Registrant Name INNOVATIVE SOLUTIONS & SUPPORT INC  
Entity Central Index Key 0000836690  
Document Type 10-Q  
Document Period End Date Dec. 31, 2019  
Amendment Flag false  
Current Fiscal Year End Date --09-30  
Entity Current Reporting Status Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   16,982,092
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q1