Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2023	Mar. 15, 2024	Jun. 30, 2023
Document Information Line Items
Entity Registrant Name	ONYX ACQUISITION CO. I
Document Type	10-K/A
Current Fiscal Year End Date	--12-31
Entity Public Float			$ 45,510,403
Amendment Flag	true
Amendment Description	This Form 10-K/A Amendment No. 1 (the “Amendment”) to the Annual Report on Form 10-K for the year ended December 31, 2023 (the “Original 10-K”) is being filed solely for the purpose of furnishing revised certifications by our principal executive officer and principal financial officer as Exhibits 32.1 and 32.2, pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (the “906 Certifications”). As a result of a typographical error, the Section 906 Certifications attached as Exhibits 32.1 and 32.2 to the Original 10-K referenced the incorrect fiscal year. Pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, this Amendment also contains new certifications by our principal executive officer and principal financial officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 (the “302 Certifications”).This Amendment contains only the Cover Page, the Explanatory Note, paragraph (a)(3) of Item 15, the Signature Page, the corrected 906 Certifications and the 302 Certifications. Except as described above, no other changes have been made to the Original 10-K.Other than as expressly set forth herein, this Amendment does not, and does not purport to, amend, update or restate the information in the Original 10-K or reflect any events that have occurred after the Original 10-K was filed. Information not affected by this Amendment remains unchanged and reflects the disclosures made at the time as of which the Original 10-K was filed. This Amendment should be read together with the Original 10-K and our other filings with the Securities and Exchange Commission.
Entity Central Index Key	0001849548
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Shell Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Document Annual Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	E9
Entity File Number	001-41003
Entity Tax Identification Number	95-1584432
Entity Address, Address Line One	104 5th Avenue
Entity Address, State or Province	NY
Entity Address, City or Town	New York
Entity Address, Postal Zip Code	10011
City Area Code	(212)
Local Phone Number	974-2844
Entity Interactive Data Current	Yes
Document Financial Statement Error Correction [Flag]	false
Documents Incorporated by Reference [Text Block]	None
Auditor Name	Marcum LLP
Auditor Location	Hartford, CT
Auditor Firm ID	688
Units, each consisting of one Class A Ordinary Share, $0.0001 par value per share, and one-half of one redeemable warrant
Document Information Line Items
Trading Symbol	ONYXU
Title of 12(b) Security	Units, each consisting of one Class A Ordinary Share, $0.0001 par value per share, and one-half of one redeemable warrant
Security Exchange Name	NASDAQ
Class A Ordinary Shares included as part of the Units
Document Information Line Items
Trading Symbol	ONYX
Title of 12(b) Security	Class A Ordinary Shares included as part of the Units
Security Exchange Name	NASDAQ
Redeemable warrants included as part of the Units, each whole warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50 per share
Document Information Line Items
Trading Symbol	ONYXW
Title of 12(b) Security	Redeemable warrants included as part of the Units, each whole warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50
Security Exchange Name	NASDAQ
Class A Ordinary Shares
Document Information Line Items
Entity Common Stock, Shares Outstanding		7,945,461
Class B Ordinary Shares
Document Information Line Items
Entity Common Stock, Shares Outstanding		0

Onyx Acquisition Co. I 10-K/A