v3.26.1
Investment and Equity Securities - Carrying Amounts and Fair Values of Securities Held to Maturity (Detail) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Schedule of Held-to-Maturity Securities [Line Items]    
Held-to-maturity Securities, Amortized Cost $ 21,924 $ 21,992
Held-to-maturity Securities, Gross Unrealized Losses 1,551 1,784
Held-to-maturity Securities, Fair Value 20,373 20,208
Allowance for credit losses for held to maturity securities 44 45
Held-to-maturity Securities, Net Carrying Amount 21,880 21,947
State and Political Subdivisions [Member]    
Schedule of Held-to-Maturity Securities [Line Items]    
Held-to-maturity Securities, Amortized Cost 11,624 11,692
Held-to-maturity Securities, Gross Unrealized Losses 1,021 1,133
Held-to-maturity Securities, Fair Value 10,603 10,559
Held-to-maturity Securities, Net Carrying Amount 11,624 11,692
Corporate Bonds [Member]    
Schedule of Held-to-Maturity Securities [Line Items]    
Held-to-maturity Securities, Amortized Cost 10,300 10,300
Held-to-maturity Securities, Gross Unrealized Losses 530 651
Held-to-maturity Securities, Fair Value 9,770 9,649
Allowance for credit losses for held to maturity securities 44 45
Held-to-maturity Securities, Net Carrying Amount $ 10,256 $ 10,255