CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive (Loss)Income	Common Stock Par Value	Treasury Stock	Capital in Excess of Par Value	Non- Controlling Interest
Balance at beginning of period at Dec. 31, 2017	$ 1,312,048	$ 2,937	$ 1,301,147	$ 2,937	$ (253,302)	$ 667	$ (346,245)	$ 609,471	$ 310
Increase (Decrease) in Stockholders' Equity
Net income	194,766		194,745						21
Reclassification of stranded tax effects	(6,658)		6,658		(6,658)
Foreign currency translation adjustments	(62,914)				(62,898)				(16)
Changes in unrecognized pension gains (losses) and related amortization, net of tax	10,790				10,790
Changes in treasury locks, net of tax	17				17
Changes in derivative gains (losses), net of tax	1,547				1,547
Stock awards and option exercises	107,717					12	31,942	75,763
Cash dividends declared on common stock	(82,346)		(82,346)
Treasury stock purchased	(3,905)						(3,905)
Common stock repurchased and retired	(57,786)		(51,315)			(6)		(6,465)
Balance at end of period at Dec. 31, 2018	$ 1,422,871		1,371,826		(310,504)	673	(318,208)	678,769	315
Increase (Decrease) in Stockholders' Equity
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201409Member
Net income	$ 242,227		242,202						25
Foreign currency translation adjustments	(8,727)				(8,723)				(4)
Changes in unrecognized pension gains (losses) and related amortization, net of tax	(22,684)				(22,684)
Changes in treasury locks, net of tax	0
Changes in derivative gains (losses), net of tax	(37)				(37)
Stock awards and option exercises	115,307					13	23,467	91,827
Cash dividends declared on common stock	(90,208)		(90,208)
Treasury stock purchased	(86,497)						(86,497)
Balance at end of period at Dec. 31, 2019	1,572,252	$ (1,377)	1,523,820	$ (1,377)	(341,948)	686	(381,238)	770,596	336
Increase (Decrease) in Stockholders' Equity
Net income	214,090		214,040						50
Foreign currency translation adjustments	79,109				79,099				10
Changes in unrecognized pension gains (losses) and related amortization, net of tax	(19,175)				(19,175)
Changes in treasury locks, net of tax	0
Changes in derivative gains (losses), net of tax	315				315
Stock awards and option exercises	98,229					9	19,655	78,565
Cash dividends declared on common stock	(92,658)		(92,658)
Balance at end of period at Dec. 31, 2020	$ 1,850,785		$ 1,643,825		$ (281,709)	$ 695	$ (361,583)	$ 849,161	$ 396
Increase (Decrease) in Stockholders' Equity
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member