v3.26.3
Cover - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Oct. 01, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Current Fiscal Year End Date --12-31    
Document Period End Date Dec. 31, 2025    
Document Transition Report false    
Entity File Number 001-34584    
Entity Registrant Name HARBOR DIVERSIFIED, INC.    
Entity Incorporation State Country Code DE    
Entity Tax Identification Number 13-3697002    
Entity Address Address Line1 5601 W. Grande Market Drive    
Entity Address Address Line2 Suite C    
Entity Address City Or Town Appleton    
Entity Address State Or Province WI    
Entity Address Postal Zip Code 54913    
City Area Code 920    
Local Phone Number 862-8370    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status No    
Entity Interactive Data Current No    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 10.7
Entity Common Stock, Shares Outstanding   58,429,836  
Documents Incorporated by Reference None.    
Central Index Key 0000899394    
Amendment Flag false    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY