Calculation of Earnings Per Share - Calculation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share [Abstract]
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.91	$ 0.96	$ 2.95	$ 3.05
Calculation of Basic Earnings Per Share:
Net Income	$ 16,133	$ 17,051	$ 52,477	$ 53,985
Weighted shares outstanding (shares)	17,794,320	17,730,833	17,777,203	17,704,592
Basic Earnings Per Share (in dollars per share)	$ 0.91	$ 0.96	$ 2.95	$ 3.05
Reconciliation of Numerator:
Net Income	$ 16,133	$ 17,051	$ 52,477	$ 53,985
Reconciliation of Denominator:
Weighted shares outstanding - Basic (shares)	17,794,320	17,730,833	17,777,203	17,704,592
Effect of dilutive securities:
Share-based compensation (shares)	57,704	79,038	64,751	81,037
Adjusted denominator-Diluted (shares)	17,852,024	17,809,871	17,841,954	17,785,629
Income (Loss) from Continuing Operations, Per Diluted Share	$ 0.90	$ 0.96	$ 2.94	$ 3.04
Diluted Earnings Per Share (in dollars per share)	$ 0.90	$ 0.96	$ 2.94	$ 3.04
Net Income	$ 16,133	$ 17,051	$ 52,477	$ 53,985
Basic (shares)	17,794,320	17,730,833	17,777,203	17,704,592
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.91	$ 0.96	$ 2.95	$ 3.05
Basic (in dollars per share)	$ 0.91	$ 0.96	$ 2.95	$ 3.05
Share-based compensation (shares)	57,704	79,038	64,751	81,037
Diluted (shares)	17,852,024	17,809,871	17,841,954	17,785,629
Income (Loss) from Continuing Operations, Per Diluted Share	$ 0.90	$ 0.96	$ 2.94	$ 3.04
Diluted (in dollars per share)	$ 0.90	$ 0.96	$ 2.94	$ 3.04
Retained Earnings [Member]
Earnings Per Share [Abstract]
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	$ 16,133	$ 17,051	$ 52,477	$ 53,985
Calculation of Basic Earnings Per Share:
Net Income	16,133	17,051	52,477	53,985
Reconciliation of Numerator:
Net Income	16,133	17,051	52,477	53,985
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	16,133	17,051	52,477	53,985
Net Income	$ 16,133	$ 17,051	$ 52,477	$ 53,985