Reconciliations of Equity - Reconciliations of Total Equity (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Reconciliations of total equity
Beginning Balance	$ 1,216,490	$ 1,166,065
Issuance of common stock under incentive compensation plan	865	1,514
Stock-based and deferred compensation	(2,640)	(2,612)
Net income	13,893	16,142
Other comprehensive income (loss)	(5,664)	16,964
Cash dividends paid:
Common stock	(8,422)	(8,160)
Ending Balance	1,214,522	1,189,913
Common Stock [Member]
Reconciliations of total equity
Beginning Balance	27,006	26,841
Issuance of common stock under incentive compensation plan	21	26
Stock-based and deferred compensation	98	91
Cash dividends paid:
Ending Balance	27,125	26,958
Additional Paid-in Capital [Member]
Reconciliations of total equity
Beginning Balance	247,032	237,202
Issuance of common stock under incentive compensation plan	844	1,488
Stock-based and deferred compensation	461	895
Cash dividends paid:
Ending Balance	248,337	239,585
Common Treasury Stock [Member]
Reconciliations of total equity
Beginning Balance	(184,412)	(180,596)
Stock-based and deferred compensation	(3,199)	(3,598)
Cash dividends paid:
Ending Balance	(187,611)	(184,194)
Accumulated Other Comprehensive Income (Loss) [Member]
Reconciliations of total equity
Beginning Balance	(130,602)	(167,512)
Other comprehensive income (loss)	(5,664)	16,964
Cash dividends paid:
Ending Balance	(136,266)	(150,548)
Retained Earnings [Member]
Reconciliations of total equity
Beginning Balance	1,257,466	1,250,130
Net income	13,893	16,142
Cash dividends paid:
Common stock	(8,422)	(8,160)
Ending Balance	$ 1,262,937	$ 1,258,112