Consolidated Statements Of Changes In Equity (USD $) In Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Non-Controlling Interest [Member]
Balance at Dec. 31, 2010	$ 2,023,464	$ 433,942	$ 971,293	$ 555,778	$ (2,371)	$ 63,345	$ 1,477
Net income	130,567			129,487			1,080
Other comprehensive income	19,655					19,655
Distributions to non-controlling interest	(358)						(358)
Purchase of treasury stock	(18,341)				(18,341)
Issuance of stock under purchase and equity compensation plans	13,363	1,563	5,483		6,317
Net tax benefit related to equity compensation plans	955		955
Stock-based compensation	2,372		2,372
Issuance of nonvested stock awards	0	976	(856)		(120)
Cash dividends	(40,110)			(40,110)
Balance at Jun. 30, 2011	2,131,567	436,481	979,247	645,155	(14,515)	83,000	2,199
Balance at Dec. 31, 2011	2,170,361	446,387	1,042,065	575,419	(8,362)	110,538	4,314
Net income	138,050			136,532			1,518
Other comprehensive income	26,194					26,194
Distributions to non-controlling interest	(1,614)						(1,614)
Purchase of treasury stock	(71,652)				(71,652)
Issuance of stock under purchase and equity compensation plans	6,785		(3,491)		10,276
Net tax benefit related to equity compensation plans	744		744
Stock-based compensation	2,555		2,555
Issuance of nonvested stock awards	0		(8,350)		8,350
Cash dividends	(40,654)			(40,654)
Balance at Jun. 30, 2012	$ 2,230,769	$ 446,387	$ 1,033,523	$ 671,297	$ (61,388)	$ 136,732	$ 4,218