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 Income (Loss) [Member]	Treasury Stock [Member]	Total
Balance at beginning of year at Dec. 31, 2015		$ 195,056	$ 910,074	$ 6,212,201	$ (704,542)	$ (1,306,061)
Foreign currency translation gain, net of income taxes					148,669		$ 148,669
Net income (loss) for the period				(198,802)			(198,802)
Restricted stock transactions and other			(9,972)
Cash dividends				(60,267)
Retirement and postretirement benefit plans, net of income taxes					2,516		2,516
Sale of stock under employee stock purchase plans						197
Stock-based compensation			6,759
Other			(128)
Deferred loss on interest rate hedges reclassified to interest expense, net of income taxes					482		482
Awarded restricted stock, net of forfeitures						8,906
Balance at end of year at Mar. 31, 2016		195,056	906,733	5,953,132	(552,875)	(1,296,958)	5,205,088
Balance at beginning of year at Dec. 31, 2016		195,056	916,799	5,729,596	(628,212)	(1,296,560)	4,916,679
Foreign currency translation gain, net of income taxes					22,664		22,664
Net income (loss) for the period				58,464			58,464
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