v3.26.3
Investment Securities - Narrative (Details)
 3 Months Ended 9 Months Ended
Sep. 30, 2026
USD ($)
security
numberOfPosition
Sep. 30, 2025
USD ($)
Sep. 30, 2026
USD ($)
security
numberOfPosition
Sep. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
security
numberOfPosition
Schedule of Held-to-maturity Securities [Line Items]          
Available for sale debt securities, at fair value $ 3,284,350,000   $ 3,284,350,000   $ 3,164,756,000
Held to maturity debt securities 257,084,000   257,084,000   282,127,000
Accrued interest on available for sale debt securities 12,700,000   12,700,000   $ 10,900,000
Proceeds from sales of available for sale debt securities 0 $ 0 23,866,000 $ 1,670,000  
Gain recognized on sale of securities     0 87,000  
Loss recognized on sale of securities     806,000 0  
Proceeds from calls on securities 1,100,000 0 6,500,000 4,000,000  
Gain recognized calls on sale of securities 86,000   580,000 67,000  
Loss recognized calls on sale of securities $ 0   $ 0 0  
Securities available for sale, number of securities in an unrealized loss position | numberOfPosition 728   728   406
Accrued interest on held to maturity debt securities $ 2,300,000   $ 2,300,000   $ 2,600,000
Proceeds from sale of held-to-maturity securities 0 0 0 0  
Held to maturity securities, proceeds from calls 870,000 910,000 5,200,000 11,000,000  
Held to maturity securities, recognized gain on calls 0 0 3,000 0  
Held to maturity securities, recognized loss on calls 0 $ 0 0 $ 0  
Held-to-maturity, debt securities, allowance $ 22,000   $ 22,000   $ 16,000
Number of securities in an unrealized loss position | security 393   393   221
AAA          
Schedule of Held-to-maturity Securities [Line Items]          
Total portfolio (as a percent)     17.00%    
AA          
Schedule of Held-to-maturity Securities [Line Items]          
Total portfolio (as a percent)     69.00%    
A          
Schedule of Held-to-maturity Securities [Line Items]          
Total portfolio (as a percent)     6.00%    
A Rated or Not Rated          
Schedule of Held-to-maturity Securities [Line Items]          
Total portfolio (as a percent)     8.00%