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, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings Per Share [Abstract]
Income (Loss) from Continuing Operations, Per Basic Share		$ 0.82	$ 0.91	$ 2.89	$ 2.95
Calculation of Basic Earnings Per Share:
Net Income		$ 18,271	$ 16,133	$ 64,439	$ 52,477
Weighted shares outstanding (shares)	[1]	22,284,000	17,794,000	22,267,000	17,777,000
Basic Earnings Per Share (in dollars per share)		$ 0.82	$ 0.91	$ 2.89	$ 2.95
Reconciliation of Numerator:
Net Income		$ 18,271	$ 16,133	$ 64,439	$ 52,477
Reconciliation of Denominator:
Weighted shares outstanding - Basic (shares)	[1]	22,284,000	17,794,000	22,267,000	17,777,000
Effect of dilutive securities:
Share-based compensation (shares)		51,000	58,000	53,000	65,000
Adjusted denominator-Diluted (shares)		22,335,000	17,852,000	22,320,000	17,842,000
Income (Loss) from Continuing Operations, Per Diluted Share		$ 0.82	$ 0.90	$ 2.89	$ 2.94
Diluted Earnings Per Share (in dollars per share)		$ 0.82	$ 0.90	$ 2.89	$ 2.94
Net Income		$ 18,271	$ 16,133	$ 64,439	$ 52,477
Basic (shares)	[1]	22,284,000	17,794,000	22,267,000	17,777,000
Income (Loss) from Continuing Operations, Per Basic Share		$ 0.82	$ 0.91	$ 2.89	$ 2.95
Basic (in dollars per share)		$ 0.82	$ 0.91	$ 2.89	$ 2.95
Share-based compensation (shares)		51,000	58,000	53,000	65,000
Diluted (shares)		22,335,000	17,852,000	22,320,000	17,842,000
Income (Loss) from Continuing Operations, Per Diluted Share		$ 0.82	$ 0.90	$ 2.89	$ 2.94
Diluted (in dollars per share)		$ 0.82	$ 0.90	$ 2.89	$ 2.94
Proceeds from Issuance of Senior Long-Term Debt				$ 550,000
Retained Earnings [Member]
Earnings Per Share [Abstract]
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent		$ 18,271	$ 16,133	64,439	$ 52,477
Calculation of Basic Earnings Per Share:
Net Income		18,271	16,133	64,439	52,477
Reconciliation of Numerator:
Net Income		18,271	16,133	64,439	52,477
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent		18,271	16,133	64,439	52,477
Net Income		$ 18,271	$ 16,133	$ 64,439	$ 52,477

[1]  (1) Weighted average shares for the three and six months ended June 30, 2024 reflect the impact of 4.4 million common shares issued in November 2023 in connection with the acquisition of FCG. See Notes 3 and 9 for additional details on the acquisition and related equity offering.