Income Taxes - Income Tax Expense from Operations from the Amount Computed by Applying the U.S. Federal Income Tax Statutory Rate of 21% to Income Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income tax computed at federal statutory tax rate, Amount	$ 12,359	$ 14,502	$ 16,249
Tax Jurisdiction of Domicile [Extensible Enumeration]	country:US	country:US	country:US
State income tax, Amount	$ 912	$ 679	$ 779
Tax-exempt interest, net, Amount	(1,908)	(1,945)	(1,997)
All other	351	376	225
Other	(8)	8	13
Income tax expense, Total	$ 11,706	$ 13,620	$ 15,269
Income tax computed at federal statutory tax rate, Percentage	21.00%	21.00%	21.00%
State income tax, Percentage	1.50%	1.00%	1.00%
Tax-exempt interest, net, Percentage	(3.20%)	(2.80%)	(2.60%)
All other, Percentage	0.60%	0.50%	0.30%
Other, Percentage	0.00%	0.00%	0.00%
Income tax expense, Percentage Total	19.90%	19.70%	19.70%