S-K 1602(b)(6) Prospectus Summary, Sponsor Compensation	Aug. 21, 2026 USD ($) $ / shares shares
SPAC Prospectus Summary, Sponsor Compensation [Line Items]
Price Paid or to be Paid for Securities, Total Amount	$ 200,000
Dune Acquisition Holdings III LLC [Member]
SPAC Prospectus Summary, Sponsor Compensation [Line Items]
Price Paid or to be Paid for Securities, Total Amount	20,000
Dune Acquisition Holdings III LLC [Member] \| Common Class B [Member]
SPAC Prospectus Summary, Sponsor Compensation [Line Items]
Price Paid or to be Paid for Securities, Total Amount	$ 25,000
Securities Issued or to be Issued, Shares (in Shares) \| shares	4,800,000
Dune Acquisition Holdings III LLC [Member] \| Private Placement Warrants [Member]
SPAC Prospectus Summary, Sponsor Compensation [Line Items]
Securities Issued or to be Issued, Shares (in Shares) \| shares	1,300,000
Dune Acquisition Holdings III LLC [Member] \| Working Capital [Member]
SPAC Prospectus Summary, Sponsor Compensation [Line Items]
Price Paid or to be Paid for Securities, Total Amount	$ 1,500,000
Dune Acquisition Holdings III LLC [Member] \| Warrants [Member]
SPAC Prospectus Summary, Sponsor Compensation [Line Items]
Price Paid or to be Paid for Securities, Per Share (in Dollars per share) \| $ / shares	$ 1