v3.26.1
Document and Entity Information
 12 Months Ended
Dec. 31, 2025
shares
Entity Listings [Line Items]  
Document Type 20-F
Amendment Flag false
Document Registration Statement false
Document Annual Report true
Document Period End Date Dec. 31, 2025
Current Fiscal Year End Date --12-31
Document Fiscal Year Focus 2025
Document Fiscal Period Focus FY
Document Transition Report false
Document Shell Company Report false
Entity File Number 001-34848
Entity Registrant Name SEANERGY MARITIME HOLDINGS CORP.
Entity Central Index Key 0001448397
Entity Incorporation, State or Country Code 1T
Entity Address, Address Line One 154 Vouliagmenis Avenue
Entity Address, Postal Zip Code 166 74
Entity Address, City or Town Glyfada
Entity Address, Country GR
Entity Well-known Seasoned Issuer No
Entity Voluntary Filers No
Entity Current Reporting Status Yes
Entity Interactive Data Current Yes
Entity Filer Category Accelerated Filer
Entity Emerging Growth Company false
ICFR Auditor Attestation Flag true
Document Financial Statement Error Correction [Flag] false
Document Accounting Standard U.S. GAAP
Entity Shell Company false
Auditor Firm ID 1163
Auditor Name Deloitte Certified Public Accountants S.A.
Auditor Location Athens, Greece
Business Contact [Member]  
Entity Listings [Line Items]  
Contact Personnel Name Stamatios Tsantanis
Entity Address, Address Line One 154 Vouliagmenis Avenue
Entity Address, Postal Zip Code 166 74
Entity Address, City or Town Glyfada
Entity Address, Country GR
Country Region 30
City Area Code 213
Local Phone Number 0181507
Contact Personnel Fax Number 9638404
Common Stock [Member]  
Entity Listings [Line Items]  
Title of 12(b) Security Common Shares, par value $0.0001 per share
Trading Symbol SHIP
Security Exchange Name NASDAQ
Entity Common Stock, Shares Outstanding 21,114,098
Preferred Stock Purchase Rights [Member]  
Entity Listings [Line Items]  
Title of 12(b) Security Preferred Stock Purchase Rights
No Trading Symbol Flag true
Security Exchange Name NASDAQ
Series B Preferred Stock [Member]  
Entity Listings [Line Items]  
Entity Common Stock, Shares Outstanding 20,000