v3.25.2
Cover - shares
6 Months Ended
Jun. 30, 2025
Aug. 12, 2025
Aug. 08, 2025
Document Type 10-Q    
Amendment Flag false    
Document Quarterly Report true    
Document Transition Report false    
Document Period End Date Jun. 30, 2025    
Document Fiscal Period Focus Q2    
Document Fiscal Year Focus 2025    
Current Fiscal Year End Date --12-31    
Entity File Number 001-42479    
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 207    
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    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company true    
Elected Not To Use the Extended Transition Period false    
Entity Shell Company true    
Class A Ordinary Shares, par value $0.0001 per share [Member]      
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 Holder to Receive One-twelfth (1/12) of One Class A Ordinary Share upon the Consummation of a Business Combination [Member]      
Title of 12(b) Security Rights, each right entitling the holder to receive one-twelfth (1/12) of one Class A ordinary share upon the consummation of a business combination    
Trading Symbol HVIIR    
Security Exchange Name NASDAQ    
Units, each Consisting of One Class A Ordinary Share and One Right [Member]      
Title of 12(b) Security Units, each consisting of one Class A ordinary share and one right    
Trading Symbol HVIIU    
Security Exchange Name NASDAQ    
Common Class A [Member]      
Entity Common Stock, Shares Outstanding   19,690,000  
Common Class B [Member]      
Entity Common Stock, Shares Outstanding     6,333,333