Cover Page - shares	3 Months Ended
	Mar. 31, 2022	May 13, 2022
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Entity Registrant Name	Arena Fortify Acquisition Corp.
Entity Central Index Key	0001849489
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	true
Entity Address, Address Line One	405 Lexington Avenue
Entity Address, Address Line Two	59th Floor
Entity Address, City or Town	New York
Entity Address, Postal Zip Code	10174
City Area Code	212
Local Phone Number	612-3205
Entity File Number	001-41046
Entity Tax Identification Number	86-2228751
Entity Address, State or Province	NY
Capital Units [Member]
Document Information [Line Items]
Title of 12(b) Security	Units, each consisting of one share of Class A common stock, $0.0001 par value per share, and one-half of one redeemable warrant
Trading Symbol	AFACU
Security Exchange Name	NASDAQ
Warrant [Member]
Document Information [Line Items]
Title of 12(b) Security	Redeemable warrants included as part of the units, each whole warrant exercisable for one share of Class A common stock at an exercise price of $11.50
Trading Symbol	AFACW
Security Exchange Name	NASDAQ
Class A common stock [Member]
Document Information [Line Items]
Title of 12(b) Security	Shares of Class A common stock included as part of the units
Trading Symbol	AFAC
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		17,250,000
Class A common stock [Member] | Warrant [Member]
Document Information [Line Items]
Title of 12(b) Security	Shares of Class A common stock underlying redeemable warrants included as part of the units
Trading Symbol	AFAC
Security Exchange Name	NASDAQ
Class B common stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		4,312,500