Consolidated Statements of Equity - USD ($) $ in Thousands		Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Noncontrolling Interests [Member]
Beginning Balance at Dec. 31, 2017		$ 766,218	$ 26,071	$ 170,408	$ (78,561)	$ (99,563)	$ 747,045	$ 818
Issuance of common stock under stock option plan		4,163	97	4,066
Purchase of common stock		(15,500)			(15,500)
Stock-based and deferred compensation		5,220	141	8,407	(3,328)
Net income		111,105					111,117	(12)
Other comprehensive income		(41,966)				(41,920)		(46)
Cash dividends paid:
Common stock		(20,857)					(20,857)
Other	[1]	(198)					(198)
Ending Balance at Dec. 31, 2018		808,185	26,309	182,881	(97,389)	(141,483)	837,107	760
Issuance of common stock under stock option plan		3,037	60	2,977
Purchase of common stock		(13,184)			(13,184)
Stock-based and deferred compensation		3,835	124	7,277	(3,566)
Net income		103,101					103,129	(28)
Other comprehensive income		10,619				10,638		(19)
Cash dividends paid:
Common stock		(23,097)					(23,097)
Other	[2]					(5,325)	5,325
Ending Balance at Dec. 31, 2019		892,496	26,493	193,135	(114,139)	(136,170)	922,464	713
Issuance of common stock under stock option plan		2,926	48	2,878
Purchase of common stock		(15,253)			(15,253)
Stock-based and deferred compensation		6,583	117	10,703	(4,237)
Net income		127,656					126,770	886
Other comprehensive income		(638)				(711)		73
Cash dividends paid:
Common stock		(25,405)					(25,405)
Ending Balance at Dec. 31, 2020		$ 988,365	$ 26,658	$ 206,716	$ (133,629)	$ (136,881)	$ 1,023,829	$ 1,672

[1] 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.

[2] 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.