v3.26.1
Nature of Operations and Conversion Plan - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Millions
 6 Months Ended
Jul. 31, 2025
Jun. 30, 2026
Mar. 31, 2026
Dec. 31, 2025
Jun. 30, 2025
Nature Of Operations And Conversion [Line Items]          
Payments for donation $ 1.0        
Common Stock, Shares, Issued   20,076,250   20,076,250  
Common stock, outstanding   20,076,250   20,076,250  
Common Stock          
Nature Of Operations And Conversion [Line Items]          
Issuance of common shares donated to Avidia Bank Charitable Foundation, Shares 900,000        
Common stock, outstanding 20,076,250 20,076,250 20,076,250 20,076,250 0
Common Stock | Bank's Employee Stock Ownership Plan          
Nature Of Operations And Conversion [Line Items]          
Proceeds from isuance of common stock   $ 185.8      
Common Stock | Plan of Conversion          
Nature Of Operations And Conversion [Line Items]          
Common stock issued 19,176,250        
Shares issued, price per share   $ 10      
Stock issued under employee stock ownership plan   1,606,100