Earnings per Common Share - Computation of Basic and Diluted Earnings per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Basic
Net income	$ 39,427	$ 40,546	$ 32,192
Less allocation of earnings and dividends to participating securities	498	173	98
Net income available to common shareholders-basic	$ 38,929	$ 40,373	$ 32,094
Weighted average common shares outstanding	15,162,032	15,408,863	16,129,875
Less average participating securities	191,402	65,648	49,012
Weighted average common shares outstanding for earnings per common share basic	14,970,630	15,343,215	16,080,863
Basic earnings per share	$ 2.60	$ 2.63	$ 2.00
Diluted
Net income available to common shareholders-diluted	$ 38,929	$ 40,373	$ 32,094
Weighted average number of shares outstanding used in the calculation of basic earnings per common share	14,970,630	15,343,215	16,080,863
Average shares and dilutive potential common shares outstanding—diluted	14,970,630	15,343,215	16,080,863
Diluted earnings per share	$ 2.60	$ 2.63	$ 2.00