Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 12, 2021
Document Information Line Items
Entity Registrant Name	Dune Acquisition Corp
Trading Symbol	DUNE
Document Type	10-Q/A
Current Fiscal Year End Date	--12-31
Amendment Flag	true
Amendment Description	References throughout this Amendment No. 1 to the Quarterly Report on Form 10-Q to “we,” “us,” the “Company” or “our company” are to Dune Acquisition Corporation, unless the context otherwise indicates.This Amendment No. 1 (“Amendment No. 1”) to the Quarterly Report on Form 10-Q amends the Quarterly Report on Form 10-Q of Dune Acquisition Corporation for the period ended September 30, 2021, as filed with the Securities and Exchange Commission (“SEC”) on November 12, 2021 (the “Q3 Form 10-Q”).On November 12, 2021, Dune Acquisition Corporation (the “Company”) filed the Q3 Form 10-Q, which included a Note 2, Revision of Previously Issued Financial Statements, (“Note 2”) that describes a revision to the Company’s classification of its Class A common stock subject to redemption issued as part of the units sold in the Company’s initial public offering (“IPO”) on December 22, 2020. As described in Note 2, upon its IPO, the Company classified a portion of the Class A common stock as permanent equity to maintain net tangible assets greater than $5,000,000 on the basis that the Company will consummate its initial business combination only if the Company has net tangible assets of at least $5,000,001. The Company’s management re-evaluated the conclusion and determined that the Class A common stock subject to redemption included certain provisions that require classification of the Class A common stock as temporary equity regardless of the minimum net tangible assets required to complete the Company’s initial business combination. As a result, management corrected the error by revising the classification of all Class A common stock subject to redemption as temporary equity. This resulted in an adjustment to the initial carrying value of the Class A common stock subject to possible redemption with the offset recorded to additional paid-in capital (to the extent available), accumulated deficit and Class A common stock.In connection with the change in presentation for the Class A common stock subject to possible redemption, the Company restated its earnings per share calculation to allocate income and losses shared pro rata between the two classes of shares. This presentation differs from the previously presented method of earnings per share, which was similar to the two-class method.The Company previously determined the changes were not qualitatively material to the Company’s previously issued financial statements and did not restate its financial statements. Instead, the Company revised its previously financial statements in Note 2 to its Q3 Form 10-Q. Although management believed that the qualitative factors that management assessed tended to support a conclusion that the misstatements were not material, these factors were not strong enough to overcome the significant quantitative errors in the financial statements. The qualitative and quantitative factors support a conclusion that the misstatements are material on a quantitative basis. Management concluded that the misstatement was of such magnitude that it is probable that the judgment of a reasonable person relying upon the financial statements would have been influenced by the inclusion or correction of the foregoing items. As such, upon further consideration of the change, the Company determined the change in classification of the Class A common stock and change to its presentation of earnings per share is material quantitatively and it should restate its previously issued financial statements.Therefore, on November 19, 2021, the Company’s management and the audit committee of the Company’s board of directors (the “Audit Committee”) concluded that the Company’s previously issued (i) audited balance sheet as of December 22, 2020 (the “Post IPO Balance Sheet”), as previously revised in the Company’s Annual Report on Form 10-K, as amended, for the fiscal year ended December 31, 2020, filed with the SEC on June 21, 2021 (the “2020 Form 10-K/A No. 1”); (ii) audited financial statements included in the 2020 Form 10-K/A No. 1; (iii) unaudited interim financial statements included in the Company’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2021, filed with the SEC on June 21, 2021; (iv) unaudited interim financial statements included in the Company’s Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2021, filed with the SEC on August 16, 2021; and (v) unaudited interim financial statements included in the Q3 Form 10-Q (the periods included in such Quarterly Reports, the “Affected Quarterly Periods”), should be restated to report all Public Shares as temporary equity and should no longer be relied upon.As such, the Company restated its financial statements for the Post IPO Balance Sheet and the year ended December 31, 2020 in an Amendment No. 2 to the 2020 Form 10-K/A (the “2020 Form 10-K/A No. 2”) and for the Affected Quarterly Periods in this Amendment No. 1.The above changes will not have any impact on the Company’s cash position and cash held in the trust account established in connection with the IPO.After re-evaluation, the Company’s management has concluded that in light of the errors described above, a material weakness existed in the Company’s internal control over financial reporting during the Quarterly Affected Periods and that the Company’s disclosure controls and procedures were not effective. The Company’s remediation plan with respect to such material weakness is described in more detail in this Amendment No. 1.
Entity Central Index Key	0001817232
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Shell Company	true
Entity Ex Transition Period	false
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-39819
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	85-1617911
Entity Address, Address Line One	700 S. Rosemary Avenue
Entity Address, Address Line Two	Suite 204
Entity Address, City or Town	West Palm Beach
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33401
City Area Code	1 (917)
Local Phone Number	742-1904
Title of 12(b) Security	Class A common stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Class A Common Stock
Document Information Line Items
Entity Common Stock, Shares Outstanding		17,250,000
Class B Common Stock
Document Information Line Items
Entity Common Stock, Shares Outstanding		4,312,500