Consolidated Statements of Shareholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance at Dec. 31, 2010	$ 771,584	$ 448	$ 597,195	$ (1,057,390)	$ 1,223,130	$ 8,201
Beginning balance, shares at Dec. 31, 2010		32,425,315
Exercise of stock options and restricted stock units, shares		450,613
Exercise of stock options and restricted stock units, Value	20,770			36,843	(16,073)
Repurchases of Common Stock, Shares		(1,285,827)
Repurchases of Common Stock, Value	(204,578)			(204,578)
Tax benefit resulting from exercise of certain employee stock options	6,737		6,737
Share-based compensation	12,270		12,270
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(95,139)					(95,139)
Net earnings	269,493				269,493
Ending balance at Dec. 31, 2011	781,137	448	616,202	(1,225,125)	1,476,550	(86,938)
Ending balance, shares at Dec. 31, 2011		31,590,101
Exercise of stock options and restricted stock units, shares	457,732	457,732
Exercise of stock options and restricted stock units, Value	21,927			39,873	(17,946)
Repurchases of Common Stock, Shares	(1,637,827)	(1,637,827)
Repurchases of Common Stock, Value	(278,672)			(278,672)
Tax benefit resulting from exercise of certain employee stock options	9,318		9,318
Share-based compensation	13,185		13,185
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(10,523)					(10,523)
Net earnings	290,847				290,847
Ending balance at Dec. 31, 2012	827,219	448	638,705	(1,463,924)	1,749,451	(97,461)
Ending balance, shares at Dec. 31, 2012	30,410,006	30,410,006
Exercise of stock options and restricted stock units, shares	398,646	398,646
Exercise of stock options and restricted stock units, Value	19,745			37,870	(18,125)
Repurchases of Common Stock, Shares	(1,321,577)	(1,321,577)
Repurchases of Common Stock, Value	(294,976)			(294,976)
Tax benefit resulting from exercise of certain employee stock options	1,906		1,906
Share-based compensation	12,639		12,639
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	62,425					62,425
Net earnings	306,094				306,094
Ending balance at Dec. 31, 2013	$ 935,052	$ 448	$ 653,250	$ (1,721,030)	$ 2,037,420	$ (35,036)
Ending balance, shares at Dec. 31, 2013	29,487,075	29,487,075