CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2009	$ 3,110,370	$ 14,237	$ 1,078,337	$ 2,169,526	$ (1,409)	$ (150,321)
Beginning Balance (in shares) at Dec. 31, 2009		113,833
Stock issued under share-based compensation plans (in shares)		543
Stock issued under share-based compensation plans	347	78	2,846	0	(2,577)	0
Stock-based compensation	6,558	0	6,558	0	0	0
Excess tax benefit from stock-based compensation plans	15	0	15	0	0	0
Net income	155,539	0	0	155,539	0	0
Ending Balance at Jun. 30, 2010	3,272,829	14,315	1,087,756	2,325,065	(3,986)	(150,321)
Ending Balance (in shares) at Jun. 30, 2010		114,376
Beginning Balance at Dec. 31, 2010	3,752,310	15,794	1,433,999	2,449,521	(1,509)	(145,495)
Beginning Balance (in shares) at Dec. 31, 2010		126,294
Stock issued under share-based compensation plans (in shares)		1,111
Stock issued under share-based compensation plans	14,829	146	17,815	0	(3,132)	0
Stock-based compensation	8,941	0	8,941	0	0	0
Excess tax benefit from stock-based compensation plans	4,664	0	4,664	0	0	0
Net income	497,931	0	0	497,931	0	0
Ending Balance at Jun. 30, 2011	$ 4,278,675	$ 15,940	$ 1,465,419	$ 2,947,452	$ (4,641)	$ (145,495)
Ending Balance (in shares) at Jun. 30, 2011		127,405