Cover Page - USD ($)	11 Months Ended
	Dec. 31, 2021	Mar. 11, 2022
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Document Annual Report	true
Document Transition Report	false
Entity Registrant Name	AltEnergy Acquisition Corp.
Entity Central Index Key	0001852016
Entity File Number	001-40984
Entity Tax Identification Number	84-2157013
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	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 Incorporation, State or Country Code	DE
Entity Address, Address Line One	600 Lexington Avenue
Entity Address, Address Line Two	9th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10022
City Area Code	203
Local Phone Number	299-1400
Entity Public Float	$ 226,550,000
Auditor Name	Marcum LLP
Auditor Firm ID	688
Auditor Location	New York, NY
Capital Units
Document Information [Line Items]
Title of 12(b) Security	Units, each consisting of one share of Class A common stock and one-half of one redeemable warrant
Trading Symbol	AEAEU
Security Exchange Name	NASDAQ
Common Class A
Document Information [Line Items]
Title of 12(b) Security	Class A common stock, par value $0.0001 per share
Trading Symbol	AEAE
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		23,000,000
Warrant
Document Information [Line Items]
Title of 12(b) Security	Warrants, each whole warrant exercisable for one share of Class A common stock, each at an exercise price of $11.50 per share
Trading Symbol	AEAEW
Security Exchange Name	NASDAQ
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		5,750,000