Basis of Accounting	9 Months Ended
Basis of Accounting	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Accounting [Text Block]	(1) The condensed statements included herein have been prepared by the registrant, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission, and reflect all adjustments which are, in the opinion of management, necessary to a fair statement of the results of operations for the interim period, on a basis consistent with the annual audited statements. The adjustments made to these condensed statements consist only of normal recurring adjustments. Certain information, accounting policies, and footnote disclosures normally included in financial statements prepared in accordance with United States Generally Accepted Accounting Principles (US GAAP) have been condensed or omitted pursuant to such rules and regulations, although the registrant believes that the disclosures are adequate to make the information presented not misleading. It is suggested that these condensed financial statements be read in conjunction with the financial statements and the summary of significant accounting policies and notes thereto included in the registrant’s latest annual report on Form 10‑K.

AEI INCOME & GROWTH FUND XXI LTD PARTNERSHIP 10-Q