Reconciliations of Equity - Reconciliations of Total Equity (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019		Mar. 31, 2018
Reconciliations of total equity
Beginning Balance	[2]	$ 808,185	[1]	$ 766,218
Issuance of common stock under stock option plan		1,890		3,155
Purchase of common stock		(77)		(2,500)
Stock-based and deferred compensation		(1,360)		(1,136)
Net income	[1],[3]	24,978		31,945	[2]
Other comprehensive income		4,248		9,567
Cash dividends paid:
Common stock		(5,643)		(5,092)
Other	[4]			(198)
Ending Balance		832,221	[1]	801,959
Common Stock [Member]
Reconciliations of total equity
Beginning Balance	[2]	26,309		26,071
Issuance of common stock under stock option plan		39		77
Stock-based and deferred compensation		93		120
Cash dividends paid:
Ending Balance		26,441		26,268
Additional Paid-in Capital [Member]
Reconciliations of total equity
Beginning Balance	[2]	182,881		170,408
Issuance of common stock under stock option plan		1,851		3,078
Stock-based and deferred compensation		1,179		1,725
Cash dividends paid:
Ending Balance		185,911		175,211
Treasury Stock [Member]
Reconciliations of total equity
Beginning Balance	[2]	(97,389)		(78,561)
Purchase of common stock		(77)		(2,500)
Stock-based and deferred compensation		(2,632)		(2,981)
Cash dividends paid:
Ending Balance		(100,098)		(84,042)
Accumulated Other Comprehensive Income (Loss) [Member]
Reconciliations of total equity
Beginning Balance	[2]	(141,483)		(99,563)
Other comprehensive income		4,228		9,535
Cash dividends paid:
Other	[5]	(5,325)
Ending Balance		(142,580)		(90,028)
Retained Earnings [Member]
Reconciliations of total equity
Beginning Balance	[2]	837,107		747,045
Net income		24,984		31,952	[2]
Cash dividends paid:
Common stock		(5,643)		(5,092)
Other		5,325	[5]	(198)	[4]
Ending Balance		861,773		773,707
Noncontrolling Interest [Member]
Reconciliations of total equity
Beginning Balance	[2],[6]	760		818
Net income	[6]	(6)		(7)	[2]
Other comprehensive income	[6]	20		32
Cash dividends paid:
Ending Balance	[6]	$ 774		$ 843

[1] The 2018 amounts for the noted line items have been changed from the amounts originally reported as a result of the Company’s first quarter 2019 change in method of accounting for U.S. inventory valuation from LIFO to FIFO.

[2] The retained earnings and net income amounts for the noted line items have been changed from the amounts originally reported as a result of the Company’s first quarter 2019 change in method of accounting for U.S. inventory valuation from LIFO to FIFO.

[3] The 2018 amounts for the noted line items have been changed from the amounts originally reported as a result of the Company’s first quarter 2019 change in method of accounting for U.S. inventory valuation from the last in, first out (LIFO) basis to the first in, first out (FIFO) basis.

[4] Reflects beginning retained earnings adjustment as a result of the Company’s first quarter 2018 adoption of ASU No. 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory.

[5] Reflects beginning retained earnings adjustment as a result of the Company’s first quarter 2019 adoption of ASU No. 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. See Note 19 for more details.

[6] Reflects the noncontrolling interest in the Company’s China joint venture.