CONSOLIDATED STATEMENT OF SHAREHOLDERS EQUITY - USD ($) $ in Thousands	Total	Common stock	Capital in excess of par value	Retained earnings	Accumulated other comprehensive (loss) income	Treasury stock	Non-controlling interest	Total
Balance at Dec. 31, 2014		$ 14,470	$ 140,008	$ 3,350,734	$ (540,430)	$ (1,446,221)	$ 4,128	$ 1,522,689
Balance, Shares at Dec. 31, 2014						(35,080,600)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 419,247			419,247			544	419,791
Cumulative translation adjustment	(124,157)				(124,157)			(124,157)
Gains (losses) on derivatives qualifying as hedges; net of tax	(2,970)				(2,970)			(2,970)
Pension liability and postretirement adjustment; net of tax	54,117				54,117			54,117
Cash dividends declared				(165,727)				(165,727)
Stock options/SSAR's, value			6,099			$ 7,085		13,184
Stock options/SSAR's, shares (in shares)						194,016
Treasury share repurchases, shares						(1,074,210)
Treasury share repurchases, value						$ (121,193)		(121,193)
Vested restricted stock units and awards, value			(28,465)			$ 4,560		(23,905)
Vested restricted stock units and awards, shares						124,895
Stock-based compensation, value			23,160					23,160
Stock-based compensation, shares
Balance at Dec. 31, 2015		14,470	140,802	3,604,254	(613,440)	$ (1,555,769)	4,672	1,594,989
Balance, shares at Dec. 31, 2015						(35,835,899)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	405,031			405,031			218	405,249
Cumulative translation adjustment	(54,526)				(54,526)			(54,526)
Gains (losses) on derivatives qualifying as hedges; net of tax	(1,797)				(1,797)			(1,797)
Pension liability and postretirement adjustment; net of tax	(10,332)				(10,332)			(10,332)
Cash dividends declared				(190,750)				(190,750)
Stock options/SSAR's, value			8,952			$ 1,335		10,287
Stock options/SSAR's, shares (in shares)						30,015
Treasury share repurchases, shares						(1,058,018)
Treasury share repurchases, value						$ (127,443)		(127,443)
Vested restricted stock units and awards, value			(21,860)			$ 2,730		(19,130)
Vested restricted stock units and awards, shares						218,749
Stock-based compensation, value			24,587					24,587
Stock-based compensation, shares
Balance at Dec. 31, 2016	$ 1,631,134	14,470	152,481	3,818,535	(680,095)	$ (1,679,147)	4,890	1,631,134
Balance, shares at Dec. 31, 2016	(36,645,153)					(36,645,153)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative adjustment relating to the adoption of ASC 2016-16				(33,719)				(33,719)
Net income	$ 295,665						202	295,867
Cumulative translation adjustment	54,609				54,609			54,609
Gains (losses) on derivatives qualifying as hedges; net of tax	(17,936)				(17,936)			(17,936)
Pension liability and postretirement adjustment; net of tax	5,940				5,940			5,940
Cash dividends declared				(209,860)				(209,860)
Stock options/SSAR's, value			4,558			$ 1,208		5,766
Stock options/SSAR's, shares (in shares)						24,423
Treasury share repurchases, shares						(459,264)
Treasury share repurchases, value						$ (58,069)		(58,069)
Vested restricted stock units and awards, value			20,779			$ 9,774		(11,005)
Vested restricted stock units and awards, shares						169,185
Stock-based compensation, value			26,567					26,567
Balance at Dec. 31, 2017	$ 1,689,294	$ 14,470	$ 162,827	$ 3,870,621	$ (637,482)	$ (1,726,234)	$ 5,092	$ 1,689,294
Balance, shares at Dec. 31, 2017	(36,910,809)					(36,910,809)