| Significant Accounting Policies (Policies) | 9 Months Ended |
| Sep. 30, 2018 |
| Accounting Policies [Abstract] | |
| Basis of Accounting, Policy [Policy Text Block] | (a) Adoption of US GAAP: The Company’s consolidated financial statements have been prepared by management in accordance with United States generally accepted accounting principles (U.S. GAAP). Comparative figures, which were previously presented in accordance with International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board have been adjusted as necessary to be compliant with the Company’s policies under U.S. GAAP and are further described in note 12. (b) Basis of presentation: These consolidated financial statements of Aptose Biosciences Inc, which include the accounts of its subsidiaries have been prepared in accordance with U.S. generally accepted accounting principles, or U.S GAAP. All intercompany transactions, balances, revenue and expenses are eliminated on consolidation. |
| Use of Estimates, Policy [Policy Text Block] | (c) Significant accounting policies, estimates and judgments: The preparation of these consolidated financial statements requires management to make judgments, estimates and assumptions that affect the application of accounting policies and reported amounts of assets and liabilities at the date of the consolidated financial statements and reported amounts of revenue and expenses during the reporting period. Actual outcomes could differ from those estimates. The consolidated financial statements include estimates, which, by their nature, are uncertain. The impacts of such estimates are pervasive throughout the consolidated financial statements and may The estimates and underlying assumptions are reviewed on a regular basis. Revisions to accounting estimates are recognized in the period in which the estimate is revised and in any future periods affected. |
| Foreign Currency Transactions and Translations Policy [Policy Text Block] | (d) Foreign currency The functional and presentation currency of the Company is the US dollar. Effective January 1, 2017, 1986 2014 2015 2016, January 2017. |
| Cash and Cash Equivalents, Policy [Policy Text Block] | (e) Cash and cash equivalents Cash and cash equivalents are short-term highly liquid investments with original maturities of three |
| Investment, Policy [Policy Text Block] | (f) Investments: Investments consist of time deposits with original maturities greater than three |
| Concentration Risk, Credit Risk, Policy [Policy Text Block] | (g) Concentration of risk: The company is subject to credit risk from the Company’s cash and cash equivalents and investments. The carrying amount of the financial assets represents the maximum credit exposure. The Company manages credit risk associated with its cash and cash equivalents and investments by maintaining minimum standards of R1 |
| Property, Plant and Equipment, Policy [Policy Text Block] | (h) Property and equipment: Property and equipment is measured at cost less accumulated depreciation and accumulated impairment losses. Cost includes expenditures that are directly attributable to the acquisition of the asset. The Company records depreciation at rates that charge operations with the cost of the assets over their estimated useful lives on a straight-line basis as follows: Office furniture (in years) 5 Laboratory equipment (in years) 5 Computer hardware (in years) 3 Computer software (in years) 3 Leasehold improvements (in years) Life of lease The assets’ residual value, useful lives and methods of depreciation are reviewed at each reporting period and adjusted prospectively if appropriate. |
| Research and Development Expense, Policy [Policy Text Block] | (i) Research and development: Research and development (R&D) costs are expensed as incurred. R&D costs consist primarily of salaries and benefits, stock-based compensation, manufacturing, contract services, clinical trials, intangibles, and research related overhead. Non-refundable advance payments for goods and services that will be used in future research are recorded in prepaid and other assets and are expensed when the services are performed. |
| Fair Value Measurement, Policy [Policy Text Block] | (j) Fair value: The Company measures its financial assets and liabilities at fair value. The carrying amounts for the Company’s financial instruments, including cash and cash equivalents, investments, accounts payable and accrued liabilities approximate their fair value due to their short maturities. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. |
| Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] | (k) Stock-based compensation: The Company has a stock-based compensation plan (the “Plan”) available to officers, directors, employees and consultants with grants under the Plan approved by the Company’s Board of Directors. Under the Plan, the exercise price of each option equals the closing trading price of the Company’s stock on the day prior to the grant if the grant is made during the trading day or the closing trading price on the day of grant if the grant is issued after markets have closed. Vesting is provided for at the discretion of the Board of Directors and the expiration of options is to be no 10 The Company uses the fair value based method of accounting for employee awards granted under the Plan. The Company calculates the fair value of each stock option grant using the Black-Scholes option pricing model at the grant date. The stock-based compensation cost of the options is recognized as stock-based compensation expense over the relevant vesting period of the stock options using an estimate of the number of options that will eventually vest. Stock options awarded to non-employees are accounted for at the fair value of the goods received or the services rendered. The fair value is measured at the grant date. In June 2018, No 2018 07, 718 December 15, 2018. not The Company has a stock incentive plan pursuant to which the Board may |
| Segment Reporting, Policy [Policy Text Block] | (l) Segment reporting: Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker, or CODM. The Company’s Chief Executive Officer serves as its CODM. The Company views its operations and manages its business as one |
| Income Tax, Policy [Policy Text Block] | (n) Income taxes: The Company accounts for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted rates in effect for the year in which these temporary differences are expected to be recovered or settled. Valuation allowances are provided if, based on the weight of available evidence, it is more likely than not not The Company provides reserves for potential payments of tax to various tax authorities related to uncertain tax positions and other issues. Reserves are based on a determination of whether and how much of a tax benefit taken by the Company in its tax filing is more likely than not December 31, 2017 December 31, 2017, not not |
| New Accounting Pronouncements, Policy [Policy Text Block] | (o) Recently issued accounting pronouncements not In February 2016, No. 2016 02, 842 No. 2016 02. 2016 02 December 15, 2018 first December 31, 2019 January 1, 2019. No. 2016 02 December 31, 2018 $2.0 No. 2016 02. |
