Net Income Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2011 ParticipatingSecurities ManufacturingSites	Sep. 30, 2010	Sep. 30, 2011 ParticipatingSecurities ManufacturingSites	Sep. 30, 2010
Basic
Average common shares outstanding	102,151,164	106,454,042	103,939,552	107,366,658
Net income	$ 179,877	$ 175,258	$ 427,308	$ 389,567
Less net income (loss) allocated to unvested restricted shares	(2,102)	(1,930)	(4,810)	(4,116)
Net income allocated to common shares	177,775	173,328	422,498	385,451
Basic net income per common share	$ 1.74	$ 1.63	$ 4.06	$ 3.59
Diluted
Average common shares outstanding	102,151,164	106,454,042	103,939,552	107,366,658
Stock options and other contingently issuable shares	1,972,108	1,943,695	2,221,992	1,729,278
Average common shares outstanding assuming dilution	104,123,272	108,397,737	106,161,544	109,095,936
Net income	179,877	175,258	427,308	389,567
Less net income (loss) allocated to unvested restricted shares assuming dilution	(2,070)	(1,901)	(4,736)	(4,055)
Net income allocated to common shares assuming dilution	$ 177,807	$ 173,357	$ 422,572	$ 385,512
Diluted net income per common share	$ 1.71	$ 1.60	$ 3.98	$ 3.53
Net Income Per Common Share (Textual) [Abstract]
Average common shares outstanding, anti-dilutive	100,000		100,000	100,000
Classes of participating securities	2		2
Percent common shares representing outstanding shares	99.00%		99.00%
Percent restricted shares representing outstanding shares	1.00%		1.00%