Earnings Per Share - Calculation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share Basic [Abstract]
Net income – basic	$ 65,756	$ 86,602	$ 92,690
Basic weighted average common shares	19,332,391	19,288,996	19,248,657
Basic earnings per share	$ 3.40	$ 4.49	$ 4.82
Net income – diluted	$ 65,756	$ 86,602	$ 92,690
Weighted average common shares	19,332,391	19,288,996	19,248,657
Restricted stock and stock options	77,000	75,000	80,000
Diluted weighted average common shares	19,408,619	19,363,809	19,329,238
Diluted earnings per common share	$ 3.39	$ 4.47	$ 4.80