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, 2013	$ 21,899		$ 956,918	$ (10,115)	$ 968,702
Balance (in shares) at Dec. 31, 2013	218,986
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for stock incentive plans, net	60	4,657			4,717
Stock issued for stock incentive plans, net (in shares)	600
Stock purchased and retired	(76)	(9,073)	(3,995)		(13,144)
Stock purchased and retired (in shares)	(753)
Net income			102,671		102,671
Pension adjustment, net of taxes				168	168
Foreign currency translation				(4)	(4)
Unrealized loss on securities, net of taxes				2	2
Dividends declared			(45,883)		(45,883)
Excess tax benefits for share- based payments		4,416			4,416
Balance at Jun. 30, 2014	$ 21,883		$ 1,009,711	$ (9,949)	$ 1,021,645
Balance (in shares) at Jun. 30, 2014	218,833