v3.19.2
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2019
Aug. 06, 2019
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Document Period End Date Jun. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Trading Symbol ARPO  
Entity Filer Category 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
Entity Shell Company false  
Entity Current Reporting Status Yes  
Entity File Number 001-38560  
Entity Tax Identification Number 611547850  
Entity Address, Address Line One 9987 Carver Road  
Entity Address, City or Town Cincinnati  
Entity Address, State or Province OH  
Entity Address, Postal Zip Code 45242  
City Area Code 513  
Local Phone Number 985-1920