v3.26.1
Investment Securities - Additional Information (Details)
 3 Months Ended 6 Months Ended
Jun. 30, 2026
USD ($)
security
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
security
Dec. 31, 2025
USD ($)
Jun. 30, 2025
USD ($)
Apr. 01, 2026
USD ($)
Dec. 31, 2024
USD ($)
Schedule of Available-for-sale Securities [Line Items]              
Carrying value of investment securities $ 2,620,000,000   $ 2,620,000,000 $ 2,650,000,000      
Investment securities pledged as collateral 158,700,000   158,700,000 155,800,000      
Available for sale securities sold 0 $ 0 0   $ 0    
Recovery of credit losses 0   0 (2,195,000) 0    
Allowance for credit losses, HTM 2,005,000 2,005,000 2,005,000 2,005,000 2,005,000   $ 2,005,000
Allowance for credit losses, AFS 0 $ 2,195,000 0 0 $ 2,195,000   $ 2,195,000
Debt securities available for sale unrealized loss position (226,911,000)   (226,911,000) (223,382,000)      
Fair value of unrealized losses $ 223,202,000   $ 223,202,000 222,629,000      
Percentage of Company's investment portfolio     48.00%        
Maturity description of investment portfolio     five years or less        
Number of investment securities available for sale | security 1,539   1,539        
Number of investment in debt securities available-for-sale unrealized loss position | security 1,256   1,256        
Number of investment securities held to maturity | security 512   512        
Number of investments in debt securities held-to-maturity unrealized loss position | security 496   496        
Unrealized losses $ (106,122,000)   $ (106,122,000) (98,681,000)      
U.S. government-sponsored enterprises              
Schedule of Available-for-sale Securities [Line Items]              
Allowance for credit losses, HTM 0   0 0      
Allowance for credit losses, AFS 0   0 0      
Debt securities available for sale unrealized loss position (7,237,000)   (7,237,000) (7,107,000)      
Fair value of unrealized losses $ 7,222,000   $ 7,222,000 7,075,000      
Number of investment in debt securities available-for-sale unrealized loss position | security 59   59        
Number of investments in debt securities held-to-maturity unrealized loss position | security 5   5        
Unrealized losses $ (1,932,000)   $ (1,932,000) (1,391,000)      
U.S. government-sponsored mortgage-backed securities              
Schedule of Available-for-sale Securities [Line Items]              
Allowance for credit losses, HTM 0   0 0      
Allowance for credit losses, AFS 0   0 0      
Debt securities available for sale unrealized loss position (144,283,000)   (144,283,000) (133,999,000)      
Fair value of unrealized losses $ 143,020,000   $ 143,020,000 133,863,000      
Number of investment in debt securities available-for-sale unrealized loss position | security 626   626        
Number of investments in debt securities held-to-maturity unrealized loss position | security 17   17        
Unrealized losses $ (4,752,000)   $ (4,752,000) (3,258,000)      
Private mortgage-backed securities              
Schedule of Available-for-sale Securities [Line Items]              
Allowance for credit losses, AFS 0   0 0      
Debt securities available for sale unrealized loss position (8,694,000)   (8,694,000) (6,984,000)      
Fair value of unrealized losses $ 8,276,000   $ 8,276,000 6,984,000      
Number of investment in debt securities available-for-sale unrealized loss position | security 49   49        
Non-government-sponsored asset backed securities              
Schedule of Available-for-sale Securities [Line Items]              
Allowance for credit losses, AFS $ 0   $ 0 0      
Debt securities available for sale unrealized loss position (1,136,000)   (1,136,000) (927,000)      
Fair value of unrealized losses $ 1,006,000   $ 1,006,000 914,000      
Number of investment in debt securities available-for-sale unrealized loss position | security 16   16        
State and political subdivisions              
Schedule of Available-for-sale Securities [Line Items]              
Allowance for credit losses, HTM $ 2,005,000   $ 2,005,000 2,005,000      
Allowance for credit losses, AFS 0   0 0      
Debt securities available for sale unrealized loss position (57,457,000)   (57,457,000) (65,403,000)      
Fair value of unrealized losses $ 56,399,000   $ 56,399,000 64,898,000      
Number of investment in debt securities available-for-sale unrealized loss position | security 445   445        
Number of investments in debt securities held-to-maturity unrealized loss position | security 474   474        
Unrealized losses $ (99,438,000)   $ (99,438,000) (94,032,000)      
Other securities              
Schedule of Available-for-sale Securities [Line Items]              
Allowance for credit losses, AFS 0   0 0      
Debt securities available for sale unrealized loss position (8,104,000)   (8,104,000) (8,962,000)      
Fair value of unrealized losses $ 7,279,000   $ 7,279,000 $ 8,895,000      
Number of investment in debt securities available-for-sale unrealized loss position | security 61   61        
Mountain Commerce Bancorp Inc              
Schedule of Available-for-sale Securities [Line Items]              
Investment securities - available-for-sale, net of allowance for credit losses $ 103,296,000   $ 103,296,000     $ 103,819,000