| Cover | Jan. 16, 2025 |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 16, 2025 |
| Current Fiscal Year End Date | --12-31 |
| Entity Registrant Name | HENNESSY CAPITAL INVESTMENT CORP. VII |
| Entity Central Index Key | 0001846416 |
| Entity Tax Identification Number | 98-1813620 |
| Entity Incorporation, State or Country Code | E9 |
| 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 | (775) |
| Local Phone Number | 339-1671 |
| 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 |
| Units, each consisting of one Class A ordinary share and one right | |
| Title of 12(b) Security | Units, each consisting of one Class A ordinary share and one right |
| Trading Symbol | HVIIU |
| Security Exchange Name | NASDAQ |
| Class A ordinary shares, par value $0.0001 per share | |
| Title of 12(b) Security | Class A ordinary shares, par value $0.0001 per share |
| Trading Symbol | HVII |
| Security Exchange Name | NASDAQ |
| Rights, each right entitling the holder to receive one-twelfth (1/12) of one Class A ordinary share upon the consummation of an initial business combination | |
| Title of 12(b) Security | Rights, each right entitling the holder to receive one-twelfth (1/12) of one Class A ordinary share |
| Trading Symbol | HVIIR |
| Security Exchange Name | NASDAQ |
