Annual report pursuant to Section 13 and 15(d)

Document And Entity Information

Document And Entity Information - USD ($)
12 Months Ended
Dec. 31, 2021
Mar. 22, 2022
Jun. 30, 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 FY    
Document Fiscal Year Focus 2021    
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2021    
Document Transition Report false    
Entity File Number 001-3200    
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, 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 Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
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 Public Float     $ 293,330,791
Entity Common Stock, Shares Outstanding   92,229,189  
Auditor Name KPMG LLP    
Auditor Location Vaughan, Canada    
Auditor Firm ID 85