Quarterly report pursuant to Section 13 or 15(d)

Document And Entity Information

v3.21.2
Document And Entity Information - shares
 9 Months Ended
Sep. 30, 2021
Nov. 12, 2021
Document Information [Line Items]    
Entity Central Index Key 0000882361  
Entity Registrant Name Aptose Biosciences Inc.  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Document Fiscal Period Focus Q3  
Document Fiscal Year Focus 2021  
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2021  
Document Transition Report false  
Entity File Number 1-35447  
Entity Incorporation, State or Country Code CA  
Entity Tax Identification Number 98-1136802  
Entity Address, Address Line One 251 Consumers Road, Suite 1105  
Entity Address, City or Town Toronto  
Entity Address, State or Province ON  
Entity Address, Country CA  
Entity Address, Postal Zip Code M2J 4R3  
City Area Code 647  
Local Phone Number 479-9828  
Title of 12(b) Security Common Shares, no par value  
Trading Symbol APTO  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current 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   88,948,744