Earnings per Share - Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share [Abstract]
Net income	$ 71,104,000	$ 78,120,000	$ 91,801,000
Net income allocated to unvested restricted stock awards	0	0	(26,000)
Net income allocated to common shares	$ 71,104,000	$ 78,120,000	$ 91,775,000
Weighted average shares outstanding	29,433	29,393	29,403
Average unvested restricted stock awards	0	0	(8)
Denominator for basic earnings per share—weighted-average shares outstanding	29,433	29,393	29,395
Effect of dilutive securities—stock options and restricted stock units	100	158	159
Denominator for diluted earnings per share—adjusted weighted-average shares outstanding	29,533	29,551	29,554
Basic earnings per share	$ 2.42	$ 2.66	$ 3.12
Diluted earnings per share	$ 2.41	$ 2.64	$ 3.11
Average anti-dilutive options and restricted stock units excluded from computation of diluted earnings per share	293	245	277