v3.26.1
Subordinated Debt (Details)
 3 Months Ended 6 Months Ended
Nov. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Mar. 31, 2025
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
$ / shares
Dec. 31, 2005
USD ($)
Line of Credit Facility [Line Items]                  
Other assets   $ 81,074,000     $ 81,074,000   $ 84,172,000    
Tenor spread adjustment   0.0026     0.0026     0.0026  
Interest expense   $ 10,018,000 $ 11,207,000   $ 20,253,000 $ 21,471,000      
Depreciation of debt issuance costs         $ 70,000 0      
Subordinated debt                  
Line of Credit Facility [Line Items]                  
Debt instrument, basis spread on variable rate (percent)         1.37%        
Junior subordinated debenture, effective interest rate (percent)   3.72%     3.72%        
Junior subordinated debenture   $ 10,000,000.0     $ 10,000,000.0        
Senior Subordinated Notes | Subordinated Notes Due 2035 (the “Notes”)                  
Line of Credit Facility [Line Items]                  
Debt instrument, basis spread on variable rate (percent) 3.48%                
Junior subordinated debenture $ 60,000,000.0                
Interest rate, stated percentage 6.875%                
Redemption price, percentage 100.00%                
Interest costs incurred   1,000,000.0     2,100,000        
Debt issuance costs, gross             $ 1,400,000    
Depreciation of debt issuance costs   $ 35,000     $ 70,000        
Percentage of principal amount redeemed 100.00%                
Northrim Statutory Trust Two                  
Line of Credit Facility [Line Items]                  
Other assets                 $ 10,000,000
Junior subordinated notes                 $ 10,300,000
Secured overnight financing rate period       90 days          
Debt instrument, basis spread on variable rate (percent)       1.37%          
Preferred stock, liquidation preference per share (in USD per share) | $ / shares               $ 1,000  
Junior subordinated debenture, effective interest rate (percent)   5.30%     5.30%   5.35%    
Interest expense   $ 138,000 $ 155,000   $ 276,000 $ 309,000