v3.26.1
Fair Value Measurements - Assets and Liabilities Not Measured and Reported at Fair Value on a Recurring Basis or Nonrecurring Basis (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2025
Dec. 31, 2024
Financial assets        
Securities held to maturity $ 902,853 $ 961,870    
Securities available for sale 2,842,424 2,560,818    
Loans held for sale 241,588 265,959    
Mortgage servicing rights 65,816 65,271 $ 64,539 $ 72,991
Derivative instruments 12,865 21,867    
Financial liabilities        
Derivative instruments 11,193 17,650    
Carrying Value        
Financial assets        
Cash and cash equivalents 881,203 1,070,718    
Securities held to maturity 983,032 1,030,073    
Securities available for sale 2,842,424 2,560,818    
Loans held for sale 241,588 265,959    
Loans, net 18,900,164 18,753,084    
Mortgage servicing rights 65,816 65,271    
Derivative instruments 24,621 47,098    
Financial liabilities        
Deposits 21,701,052 21,473,070    
Short-term borrowings 315,225 555,774    
Junior subordinated debentures 141,185 140,632    
Subordinated notes 655,284 359,124    
Derivative instruments 21,017 41,484    
Contingent consideration 6,327      
Fair Value        
Financial assets        
Cash and cash equivalents 881,203 1,070,718    
Securities held to maturity 902,853 961,870    
Securities available for sale 2,842,424 2,560,818    
Loans held for sale 241,588 265,959    
Loans, net 18,776,911 18,689,957    
Mortgage servicing rights 87,479 80,537    
Derivative instruments 24,621 47,098    
Financial liabilities        
Deposits 21,690,697 21,465,168    
Short-term borrowings 315,225 555,774    
Junior subordinated debentures 127,686 126,976    
Subordinated notes 657,165 352,616    
Derivative instruments 21,017 41,484    
Contingent consideration 6,327      
Fair Value | Level 1        
Financial assets        
Cash and cash equivalents 881,203 1,070,718    
Securities held to maturity 0 0    
Securities available for sale 0 0    
Loans held for sale 0 0    
Loans, net 0 0    
Mortgage servicing rights 0 0    
Derivative instruments 0 0    
Financial liabilities        
Deposits 0    
Short-term borrowings 0 0    
Junior subordinated debentures 0 0    
Subordinated notes 0 0    
Derivative instruments 0 0    
Contingent consideration 0      
Fair Value | Level 2        
Financial assets        
Cash and cash equivalents 0 0    
Securities held to maturity 902,853 961,870    
Securities available for sale 2,842,424 2,560,818    
Loans held for sale 241,588 265,959    
Loans, net 0 0    
Mortgage servicing rights 0 0    
Derivative instruments 24,621 47,098    
Financial liabilities        
Deposits 21,690,697 21,465,168    
Short-term borrowings 315,225 555,774    
Junior subordinated debentures 127,686 126,976    
Subordinated notes 657,165 352,616    
Derivative instruments 21,017 41,484    
Contingent consideration 0      
Fair Value | Level 3        
Financial assets        
Cash and cash equivalents 0 0    
Securities held to maturity 0 0    
Securities available for sale 0 0    
Loans held for sale 0 0    
Loans, net 18,776,911 18,689,957    
Mortgage servicing rights 87,479 80,537    
Derivative instruments 0 0    
Financial liabilities        
Deposits 0 0    
Short-term borrowings 0 0    
Junior subordinated debentures 0 0    
Subordinated notes 0 0    
Derivative instruments 0 $ 0    
Contingent consideration $ 6,327