Significant Accounting Policies (Policies)	3 Months Ended
Significant Accounting Policies (Policies)	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Principles of consolidation and nature of operations: Yunhong CTI Ltd, its Mexican subsidiary (Flexo Universal, S. de R.L. de C.V.), its German subsidiary (CTI Europe GmbH) and CTI Supply, Inc. (collectively, the “Company”) (i) design, manufacture and distribute metalized and latex balloon products throughout the world and (ii) operate systems for the production, lamination, coating and printing of films used for food packaging and other commercial uses and for conversion of films to flexible packaging containers and other products. As discussed in Note 2 Discontinued Operations, effective in the third quarter of 2019, the Company determined that it was exiting the business formerly conducted by CTI Europe GmbH (“CTI Europe”). Accordingly, the operations of this entity are classified as discontinued operations in these financial statements. The condensed consolidated financial statements include the accounts of Yunhong CTI Ltd., and CTI Supply, Inc. and its majority owned subsidiaries, Flexo Universal and CTI Europe, as well as the accounts of Venture Leasing S. A. de R. L. The determination of whether or not to consolidate a variable interest entity under U.S. GAAP requires a significant amount of judgment concerning the degree of control over an entity by its holders of variable interest. To make these judgments, management has conducted an analysis of the relationship of the holders of variable interest to each other, the design of the entity, the expected operations of the entity, which holder of variable interests is most “closely associated” to the entity and which holder of variable interests is the primary beneficiary required to consolidate the entity. Upon the occurrence of certain events, management reviews and reconsiders its previous conclusion regarding the status of an entity as a variable interest entity.
Use of Estimates, Policy [Policy Text Block]	Use of estimates: In preparing financial statements in conformity with accounting principles generally accepted in the United States of America, management makes estimates and assumptions that affect the amounts reported of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period in the financial statements and accompanying notes. Actual results may differ from those estimates. The Company's significant estimates include valuation allowances for doubtful accounts and inventory valuation, and assumptions used as inputs in the Black-Scholes option-pricing model.
Earnings Per Share, Policy [Policy Text Block]	Earnings per share: Basic (loss) per share is computed by dividing net loss by the weighted average number of shares of common stock outstanding during each period. Diluted (loss) per share is computed by dividing the net loss by the weighted average number of shares of common stock and equivalents (stock options and warrants), unless anti-dilutive, during each period. As of March 31, 2021 and 2020, shares to be issued upon the exercise of options and warrants aggregated nil and 632,660, respectively. The number of shares included in the determination of earnings on a diluted basis for the three months ended March 31, 2021 and 2020 were none , as doing so would have been anti-dilutive.
New Accounting Pronouncements, Policy [Policy Text Block]	Significant Accounting Policies: The Company's significant accounting policies are summarized in Note 2 of the Company's consolidated financial statements for the year ended December 31, 2020. There were no significant changes to these accounting policies during the three months ended March 31, 2021. Net sales include revenues from sales of products and shipping and handling charges, net of estimates for product returns. Revenue is measured at the amount of consideration the Company expects to receive in exchange for the transferred products. Revenue is recognized at the point in time when we transfer the promised products to the customer and the customer obtains control over the products. The Company recognizes revenue for shipping and handling charges at the time the goods are shipped to the customer, and the costs of outbound freight are included in cost of sales, as we have elected the practical expedient included in ASC 606. The Company provides for product returns based on historical return rates. While we incur costs for sales commissions to our sales employees and outside agents, we recognize commission costs concurrent with the related revenue, as the amortization period is less than one year and we have elected the practical expedient included in ASC 606. We do not incur incremental costs to obtain contracts with our customers. Our product warranties are assurance-type warranties, which promise the customer that the products are as specified in the contract. Therefore, the product warranties are not a separate performance obligation and are accounted for as described herein. Sales taxes assessed by governmental authorities are accounted for on a net basis and are excluded from net sales.