| Document and Entity Information | Feb. 21, 2024 |
| Document And Entity Information [Line Items] | |
| Entity Registrant Name | AltEnergy Acquisition Corp |
| Amendment Flag | false |
| Entity Central Index Key | 0001852016 |
| Document Type | 8-K |
| Document Period End Date | Feb. 21, 2024 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-40984 |
| Entity Tax Identification Number | 86-2157013 |
| 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 |
| Written Communications | true |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Units Each Consisting Of One Share Of Class A Common Stock And One Half Of One Warrant [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Units, each consisting of one share of Class A common stock and one- half of one Warrant |
| Trading Symbol | AEAEU |
| Security Exchange Name | NASDAQ |
| Class A Common Stock Par Value 0.0001 Per Share [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Class A common stock, par value $0.0001 per share |
| Trading Symbol | AEAE |
| Security Exchange Name | NASDAQ |
| Warrants Each Whole Warrant Exercisable For One Share Of Class A Common Stock At An Exercise Price Of 11.50 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Warrants, each whole warrant exercisable for one share of Class A common stock at an exercise price of $11.50 |
| Trading Symbol | AEAEW |
| Security Exchange Name | NASDAQ |
