| Cover | Sep. 30, 2024 |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 30, 2024 |
| Current Fiscal Year End Date | --12-31 |
| Entity File Number | 001-40846 |
| Entity Registrant Name | Hennessy Capital Investment Corp. VI |
| Entity Central Index Key | 0001842937 |
| Entity Tax Identification Number | 86-1626937 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 195 US HWY 50 |
| Entity Address, Address Line Two | Suite 309 |
| Entity Address, City or Town | Zephyr Cove |
| Entity Address, State or Province | NV |
| Entity Address, Postal Zip Code | 89448 |
| City Area Code | 307 |
| Local Phone Number | 734-4849 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
| Shares of Class A common stock, par value $0.0001 per share | |
| Title of 12(b) Security | Shares of Class A common stock, par value $0.0001 per share |
| Trading Symbol | HCVI |
| Security Exchange Name | NASDAQ |
| Redeemable warrants, each whole warrant exercisable for one share of Class A common stock at an exercise price of $11.50 | |
| Title of 12(b) Security | Redeemable warrants, each whole warrant exercisable for one share of Class A common stock at an exercise price of $11.50 |
| Trading Symbol | HCVIW |
| Security Exchange Name | NASDAQ |
| Units, each consisting of one share of Class A common stock and one-third of one redeemable warrant | |
| Title of 12(b) Security | Units, each consisting of one share of Class A common stock and one-third of one redeemable warrant |
| Trading Symbol | HCVIU |
| Security Exchange Name | NASDAQ |
