CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Cumulative Preferred Stock [Member]	Common Stock [Member]	Capital In Excess Of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Total
Balance at beginning of year at Dec. 31, 2016		$ 195,056	$ 916,799	$ 5,729,596	$ (628,212)	$ (1,296,560)
Foreign currency translation (loss) gain, net of income taxes					22,664		$ 22,664
Net income for the year				58,464			58,464	[1]
Restricted stock transactions and other			(25,251)
Cash dividends				(43,136)
Retirement and postretirement benefit plans, net of income taxes					2,387		2,387
Sale of stock under employee stock purchase plans						71
Stock-based compensation			6,716
Other			(37)
Deferred loss on interest rate hedges reclassified to interest expense, net of income taxes					482		482
Awarded restricted stock, net of forfeitures						19,444
Balance at end of year at Mar. 31, 2017		195,056	898,227	5,744,924	(602,679)	(1,277,045)	4,958,483
Balance at beginning of year at Dec. 31, 2017		195,056	917,665	5,245,242	(462,243)	(1,275,529)	4,620,191
Exercise of stock options		9	(175)
Foreign currency translation (loss) gain, net of income taxes					(52,275)		(52,275)
Net income for the year				168,253			168,253
Other					(3,737)		(3,737)
Reclassification of certain tax effects from accumulated other comprehensive loss to retained earnings				30,237	(30,237)		(30,237)
Restricted stock transactions and other			(32,486)
Cash dividends				(43,258)
Retirement and postretirement benefit plans, net of income taxes					3,170		3,170
Stock-based compensation			6,187
Deferred loss on interest rate hedges reclassified to interest expense, net of income taxes					585		585
Awarded restricted stock, net of forfeitures						25,843
Balance at end of year at Mar. 31, 2018		$ 195,065	$ 891,191	$ 5,400,474	$ (544,737)	$ (1,249,686)	$ 4,692,307

[1] Reclassified to conform to current presentation (see Notes A and B).