v3.25.4
Cover Page - USD ($)
 12 Months Ended
Dec. 31, 2025
Mar. 04, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-40136    
Entity Registrant Name Amalgamated Financial Corp.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 85-2757101    
Entity Address, Address Line One 275 Seventh Avenue    
Entity Address, City or Town New York    
Entity Address, State or Province NY    
Entity Address, Postal Zip Code 10001    
City Area Code 212    
Local Phone Number 255-6200    
Title of 12(b) Security Common Stock, par value $0.01 per share    
Trading Symbol AMAL    
Security Exchange Name NASDAQ    
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    
Smaller Reporting Company false    
Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction false    
Entity Shell Company false    
Entity Public Float     $ 547,055,889
Entity Common Stock, Shares Outstanding (in shares)   29,829,356  
Documents Incorporated by Reference
The information required by Part III of this Annual Report on Form 10-K is incorporated by reference from the registrant’s definitive proxy statement relating to the 2026 Annual Meeting of Stockholders, which will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this Annual Report on Form 10-K relates.
    
Entity Central Index Key 0001823608    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Amendment Flag false