v3.26.1
Fair Value Measurements - Summary of Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Assets    
Securities available-for-sale $ 2,773,667 $ 2,655,035
Estimate of Fair Value Measurement    
Assets    
Other investments 78,843 77,737
Obligations of U.S. Government-sponsored enterprises    
Assets    
Securities available-for-sale 158,346 182,572
Obligations of states and political subdivisions    
Assets    
Securities available-for-sale 575,924 572,705
Agency mortgage-backed securities    
Assets    
Securities available-for-sale 1,868,590 1,709,311
U.S. Treasury bills    
Assets    
Securities available-for-sale 151,240 170,984
Corporate debt securities    
Assets    
Securities available-for-sale 19,567 19,463
Recurring basis | Estimate of Fair Value Measurement    
Assets    
Securities available-for-sale 2,773,667 2,655,035
Other investments 3,102 3,148
Derivative financial instruments 9,829 12,484
Total assets 2,786,598 2,670,667
Liabilities    
Derivative financial instruments 9,222 10,114
Total liabilities 9,222 10,114
Recurring basis | Obligations of U.S. Government-sponsored enterprises | Estimate of Fair Value Measurement    
Assets    
Securities available-for-sale 158,346 182,572
Recurring basis | Obligations of states and political subdivisions | Estimate of Fair Value Measurement    
Assets    
Securities available-for-sale 575,924 572,705
Recurring basis | Agency mortgage-backed securities | Estimate of Fair Value Measurement    
Assets    
Securities available-for-sale 1,868,590 1,709,311
Recurring basis | U.S. Treasury bills | Estimate of Fair Value Measurement    
Assets    
Securities available-for-sale 19,567 19,463
Recurring basis | Corporate debt securities | Estimate of Fair Value Measurement    
Assets    
Securities available-for-sale 151,240 170,984
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Assets    
Securities available-for-sale 0 0
Other investments 0 0
Derivative financial instruments 0 0
Total assets 0 0
Liabilities    
Derivative financial instruments 0 0
Total liabilities 0 0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Obligations of U.S. Government-sponsored enterprises    
Assets    
Securities available-for-sale 0 0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Obligations of states and political subdivisions    
Assets    
Securities available-for-sale 0 0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Agency mortgage-backed securities    
Assets    
Securities available-for-sale 0 0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury bills    
Assets    
Securities available-for-sale 0 0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate debt securities    
Assets    
Securities available-for-sale 0 0
Recurring basis | Significant Other Observable Inputs (Level 2)    
Assets    
Securities available-for-sale 2,773,667 2,655,035
Other investments 3,102 3,148
Derivative financial instruments 9,829 12,484
Total assets 2,786,598 2,670,667
Liabilities    
Derivative financial instruments 9,222 10,114
Total liabilities 9,222 10,114
Recurring basis | Significant Other Observable Inputs (Level 2) | Obligations of U.S. Government-sponsored enterprises    
Assets    
Securities available-for-sale 158,346 182,572
Recurring basis | Significant Other Observable Inputs (Level 2) | Obligations of states and political subdivisions    
Assets    
Securities available-for-sale 575,924 572,705
Recurring basis | Significant Other Observable Inputs (Level 2) | Agency mortgage-backed securities    
Assets    
Securities available-for-sale 1,868,590 1,709,311
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. Treasury bills    
Assets    
Securities available-for-sale 19,567 19,463
Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate debt securities    
Assets    
Securities available-for-sale 151,240 170,984
Recurring basis | Significant Unobservable Inputs (Level 3)    
Assets    
Securities available-for-sale 0 0
Other investments 0 0
Derivative financial instruments 0 0
Total assets 0 0
Liabilities    
Derivative financial instruments 0 0
Total liabilities 0 0
Recurring basis | Significant Unobservable Inputs (Level 3) | Obligations of U.S. Government-sponsored enterprises    
Assets    
Securities available-for-sale 0 0
Recurring basis | Significant Unobservable Inputs (Level 3) | Obligations of states and political subdivisions    
Assets    
Securities available-for-sale 0 0
Recurring basis | Significant Unobservable Inputs (Level 3) | Agency mortgage-backed securities    
Assets    
Securities available-for-sale 0 0
Recurring basis | Significant Unobservable Inputs (Level 3) | U.S. Treasury bills    
Assets    
Securities available-for-sale 0 0
Recurring basis | Significant Unobservable Inputs (Level 3) | Corporate debt securities    
Assets    
Securities available-for-sale $ 0 $ 0