Significant Accounting Policies (Policies)	6 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2020
Accounting Policies [Abstract]
Nature of Operations [Policy Text Block]	Nature of Operations: Consumers Bancorp, Inc. (the Corporation) is a bank holding company headquartered in Minerva, Ohio that provides, through its banking subsidiary, Consumers National Bank (the Bank), a broad array of products and services throughout its primary market area of Carroll, Columbiana, Jefferson, Stark, Summit, Wayne and contiguous counties in Ohio. The Bank's business involves attracting deposits from businesses and individual customers and using such deposits to originate commercial, mortgage and consumer loans in its primary market area.
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation : The consolidated financial statements for interim periods are unaudited and reflect all adjustments (consisting of only normal recurring adjustments), which, in the opinion of management, are necessary to present fairly the financial position and results of operations and cash flows for the periods presented. The unaudited financial statements are presented in accordance with the requirements of Form 10 -Q and do not include all disclosures normally required by accounting principles generally accepted in the United States of America. The financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Corporation's Form 10 -K for the year ended June 30, 2020. The results of operations for the interim period disclosed herein are not necessarily indicative of the results that may be expected for a full year. The consolidated financial statements include the accounts of the Corporation and the Bank. All significant inter-company transactions and accounts have been eliminated in consolidation.
Segment Reporting, Policy [Policy Text Block]	Segment Information: The Corporation is a bank holding company engaged in the business of commercial and retail banking, which accounts for substantially all the revenues, operating income, and assets. Accordingly, all of the Corporation's operations are recorded in one segment, banking.
Reclassification, Comparability Adjustment [Policy Text Block]	Reclassifications: Certain items in prior financial statements have been reclassified to conform to the current presentation. Any reclassifications had no impact on prior year net income or shareholders' equity.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Issued Accounting Pronouncements Not Yet Effective: In June 2016, the Financial Accounting Standards Board (FASB) issued ASU 2016 - 13, Financial Instruments—Credit Losses (Topic 326 ): Measurement of Credit Losses on Financial Instruments. This ASU adds a new Topic 326 to the codification and removes the thresholds that companies apply to measure credit losses on financial instruments measured at amortized cost, such as loans, receivables, and held-to-maturity debt securities. Under current U.S. generally accepted accounting principles, companies generally recognize credit losses when it is probable that the loss has been incurred. The revised guidance will remove all current loss recognition thresholds and will require companies to recognize an allowance for credit losses for the difference between the amortized cost basis of a financial instrument and the amount of amortized cost that the corporation expects to collect over the instrument's contractual life. ASU 2016 - 13 also amends the credit loss measurement guidance for available-for-sale debt securities and beneficial interests in securitized financial assets. The guidance in ASU 2016 - 13 is effective for “public business entities,” as defined in the guidance, that are SEC filers for fiscal years and for interim periods within those fiscal years beginning after December 15, 2019. Early adoption of the guidance is permitted for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. However, during July 2019, FASB unanimously voted for a proposal to delay this ASU to January 2023 for smaller reporting companies. On October 16, 2019, FASB approved a final ASU delaying the effective date. The new guidance is effective for annual and interim periods beginning after December 15, 2022 for certain entities, including smaller reporting companies. The Corporation is a smaller reporting company. In March 2020, the FASB issued ASU 2020 - 04, "Facilitation of the Effects of Reference Rate Reform on Financial Reporting". The ASU is intended to provide relief for companies preparing for discontinuation of interest rates based on LIBOR, or other reference rates that may be discontinued, and provides optional expedients and exceptions for applying GAAP to contract modifications and hedging relationships, subject to meeting certain criteria. The ASU also provides for a one -time sale and/or transfer to AFS or trading to be made for HTM debt securities that both reference an eligible reference rate and were classified as HTM before January 1, 2020. ASU 2020 - 04 is effective March 12, 2020 through December 31, 2022. The guidance requires companies to apply the guidance prospectively to contract modifications and hedging relationships while the one -time election to sell and/or transfer debt securities classified as HTM may be made any time after March 12, 2020. The Corporation does not expect ASU 2020 - 04 to have a material impact on its financial statements and disclosures.

- Definition

Disclosure of accounting policy for segment reporting.

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