CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, except Share data	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2011	$ 1,045,189	$ 1,323	$ 360,914	$ (309,196)	$ 1,053,045	$ (60,897)
Beginning Balance (in shares) at Dec. 31, 2011		132,349,534		(36,275,980)
Cash dividends ($0.08 in 2012, $ 0.13 in 2013 and $0.20 in 2014)	(7,666)				(7,666)
Proceeds from treasury stock issued from the exercise of stock options and other benefit plans, net of tax, value	7,556		1,192	6,364
Proceeds from treasury stock issued from the exercise of stock options and other benefit plans, net of tax, shares				364,724
Stock based compensation	19,242		19,242
Net income	251,732				251,732
Translation adjustment	14,428					14,428
Unrealized gain (loss) on interest rate swap contracts, net of tax ($1,040 in 2012 , $ 422 in 2013 and $136 in 2014)	(1,588)					(1,588)
Change in pension and post-retirement benefit plans, net of tax ($785 in 2012, $8,188 in 2013 and $5,887 in 2014)	(5,507)					(5,507)
Stock repurchase, value	(46,556)			(46,556)
Stock repurchase, shares				(607,400)
Ending Balance at Dec. 31, 2012	1,276,830	1,323	381,348	(349,388)	1,297,111	(53,564)
Ending Balance (in shares) at Dec. 31, 2012		132,349,534		(36,518,656)
Cash dividends ($0.08 in 2012, $ 0.13 in 2013 and $0.20 in 2014)	(12,644)				(12,644)
Proceeds from treasury stock issued from the exercise of stock options and other benefit plans, net of tax, value	21,232		11,815	9,417
Proceeds from treasury stock issued from the exercise of stock options and other benefit plans, net of tax, shares				586,175
Stock based compensation	21,896		21,896
Net income	292,235				292,235
Translation adjustment	5,345					5,345
Unrealized gain (loss) on interest rate swap contracts, net of tax ($1,040 in 2012 , $ 422 in 2013 and $136 in 2014)	644					644
Change in pension and post-retirement benefit plans, net of tax ($785 in 2012, $8,188 in 2013 and $5,887 in 2014)	12,914					12,914
Stock repurchase, value	(32,998)			(32,998)
Stock repurchase, shares				(507,105)
Unrealized gain (loss) on foreign exchange contracts, net of tax ($ 61 in 2013, and $31 in 2014)	(195)					(195)
Ending Balance at Dec. 31, 2013	1,585,259	1,323	415,059	(372,969)	1,576,702	(34,856)
Ending Balance (in shares) at Dec. 31, 2013		132,349,534		(36,439,586)
Cash dividends ($0.08 in 2012, $ 0.13 in 2013 and $0.20 in 2014)	(19,246)				(19,246)
Proceeds from treasury stock issued from the exercise of stock options and other benefit plans, net of tax, value	17,461		9,997	7,464
Proceeds from treasury stock issued from the exercise of stock options and other benefit plans, net of tax, shares				711,247
Stock based compensation	23,475		23,475
Net income	351,680				351,680
Translation adjustment	(111,776)					(111,776)
Unrealized gain (loss) on interest rate swap contracts, net of tax ($1,040 in 2012 , $ 422 in 2013 and $136 in 2014)	(210)					(210)
Change in pension and post-retirement benefit plans, net of tax ($785 in 2012, $8,188 in 2013 and $5,887 in 2014)	(12,621)					(12,621)
Stock repurchase, value	(26,757)			(26,757)
Stock repurchase, shares				(346,800)
Unrealized gain (loss) on foreign exchange contracts, net of tax ($ 61 in 2013, and $31 in 2014)	(23)					(23)
Ending Balance at Dec. 31, 2014	$ 1,807,242	$ 1,323	$ 448,531	$ (392,262)	$ 1,909,136	$ (159,486)
Ending Balance (in shares) at Dec. 31, 2014		132,349,534		(36,075,139)