v3.10.0.1
Document and Entity Information - shares
9 Months Ended
Sep. 30, 2018
Nov. 07, 2018
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Document Period End Date Sep. 30, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q3  
Trading Symbol ARPO  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period true  
Entity Registrant Name Aerpio Pharmaceuticals, Inc.  
Entity Central Index Key 0001422142  
Entity Common Stock, Shares Outstanding   40,588,004