CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) (USD $) In Thousands, unless otherwise specified	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss	Total
Balance at Dec. 31, 2012	$ 22,014		$ 891,464	$ (14,246)	$ 899,232
Balance (in shares) at Dec. 31, 2012	220,144
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for stock incentive plans, net	75	6,322			6,397
Stock issued for stock incentive plans, net (in shares)	753
Stock purchased and retired	(185)	(9,479)	(15,457)		(25,121)
Stock purchased and retired (in shares)	(1,857)
Net income			129,252		129,252
Pension adjustment, net of taxes				372	372
Foreign currency translation				(413)	(413)
Unrealized loss on securities, net of taxes				2	2
Dividends declared			(65,923)		(65,923)
Excess tax benefits for share- based payments		3,157			3,157
Balance at Sep. 30, 2013	$ 21,904		$ 939,336	$ (14,289)	$ 946,951
Balance (in shares) at Sep. 30, 2013	219,040