CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Dec. 31, 2010	$ 22,227		$ 526,201	$ (9,533)	$ 538,895
Balance (in shares) at Dec. 31, 2010	222,264
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for stock incentive plans and other, net	122	9,455			9,577
Stock issued for stock incentive plans and other, net (in shares)	1,218
Stock purchased and retired	(194)	(12,862)	(22,136)		(35,192)
Stock purchased and retired (in shares)	(1,936)
Net income			296,381		296,381
Pension adjustment, net of taxes				(3,048)	(3,048)
Gain on cash flow hedge, net of taxes				387	387
Foreign currency translation, net of taxes				(138)	(138)
Unrealized gain (loss) on securities, net of taxes				(314)	(314)
Dividends declared			(47,327)		(47,327)
Excess tax benefits for share- based payments		3,371			3,371
Three-for-two stock split	(36)	36
Three-for-two stock splits (in shares)	(358)
Balance at Dec. 31, 2011	22,119		753,119	(12,646)	762,592
Balance (in shares) at Dec. 31, 2011	221,188				221,187,660
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for stock incentive plans and other, net	152	11,105			11,257
Stock issued for stock incentive plans and other, net (in shares)	1,530
Stock purchased and retired	(201)	(13,885)	(16,515)		(30,601)
Stock purchased and retired (in shares)	(2,011)
Increased ownership interest in subsidiary, net of taxes			(5,507)		(5,507)
Net income			274,436		274,436
Pension adjustment, net of taxes				(1,707)	(1,707)
Foreign currency translation, net of taxes				265	265
Unrealized gain (loss) on securities, net of taxes				(158)	(158)
Dividends declared			(114,069)		(114,069)
Excess tax benefits for share- based payments		2,724			2,724
Three-for-two stock split	(56)	56
Three-for-two stock splits (in shares)	(563)
Balance at Dec. 31, 2012	22,014		891,464	(14,246)	899,232
Balance (in shares) at Dec. 31, 2012	220,144				220,144,287
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for stock incentive plans and other, net	70	8,107			8,177
Stock issued for stock incentive plans and other, net (in shares)	699
Stock purchased and retired	(185)	(11,285)	(13,652)		(25,122)
Stock purchased and retired (in shares)	(1,857)
Net income			166,895		166,895
Pension adjustment, net of taxes				4,928	4,928
Foreign currency translation, net of taxes				(778)	(778)
Unrealized gain (loss) on securities, net of taxes				(19)	(19)
Dividends declared			(87,789)		(87,789)
Excess tax benefits for share- based payments		3,178			3,178
Balance at Dec. 31, 2013	$ 21,899		$ 956,918	$ (10,115)	$ 968,702
Balance (in shares) at Dec. 31, 2013	218,986				218,985,816