v3.26.1
Fair Value Measurement - Summary of Recorded Amount of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Marketable equity securities $ 2,665 $ 2,692
Debt securities available for sale 1,695,669 1,731,931
Loans held for sale 1,880 2,695
Mortgage servicing rights 6,502 6,640
Total assets measured at fair value 1,706,716 1,743,958
Obligations of U.S. government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 1,097,211 1,064,028
Obligations of states and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 219,136 220,686
Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 989 4,958
Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 245,315 269,520
Non-agency mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 133,018 172,739
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Marketable equity securities 2,665 2,692
Loans held for sale 0 0
Mortgage servicing rights 0 0
Total assets measured at fair value 2,665 2,692
Level 1 | Obligations of U.S. government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 0 0
Level 1 | Obligations of states and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 0 0
Level 1 | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 0 0
Level 1 | Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 0 0
Level 1 | Non-agency mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 0 0
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Marketable equity securities 0 0
Loans held for sale 1,880 2,695
Mortgage servicing rights 0 0
Total assets measured at fair value 1,697,549 1,734,626
Level 2 | Obligations of U.S. government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 1,097,211 1,064,028
Level 2 | Obligations of states and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 219,136 220,686
Level 2 | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 989 4,958
Level 2 | Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 245,315 269,520
Level 2 | Non-agency mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 133,018 172,739
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Marketable equity securities 0 0
Loans held for sale 0 0
Mortgage servicing rights 6,502 6,640
Total assets measured at fair value 6,502 6,640
Level 3 | Obligations of U.S. government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 0 0
Level 3 | Obligations of states and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 0 0
Level 3 | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 0 0
Level 3 | Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale 0 0
Level 3 | Non-agency mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt securities available for sale $ 0 $ 0