Earnings Per Share - Calculations of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disclosure Earnings Per Share Calculations Of Basic And Diluted Earnings Per Share [Abstract]
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	$ 89,796	$ 83,467	$ 70,642
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax			$ 856
Income (Loss) from Continuing Operations, Per Basic Share	$ 5.07	$ 4.75	$ 4.23
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share	$ 0	$ 0	$ 0.05
Calculation of Basic Earnings Per Share:
Net Income	$ 89,796	$ 83,466	$ 71,498
Weighted shares outstanding - Basic (in shares)	17,722,227	17,558,078	16,711,579
Basic Earnings Per Share (in usd per share)	$ 5.07	$ 4.75	$ 4.28
Calculation of Diluted Earnings Per Share:
Net Income	$ 89,796	$ 83,466	$ 71,498
Reconciliation of Denominator:
Weighted shares outstanding - Basic (in shares)	17,722,227	17,558,078	16,711,579
Share-based Compensation	82,067	74,951	59,156
Adjusted denominator — Diluted	17,804,294	17,633,029	16,770,735
Income (Loss) from Continuing Operations, Per Diluted Share	$ 5.04	$ 4.73	$ 4.21
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Per Diluted Share	0	0	0.05
Diluted (in usd per share)	$ 5.04	$ 4.73	$ 4.26