Stockholders' Equity (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Stockholders' Equity [Abstract]
Number of preferred stock shares authorized to issue (in shares)	100,000	100,000
Par value of authorized preferred stock share (in dollars per share)	$ 100	$ 100
Number of preferred stock shares issued (in shares)	0	0
Number of common stock shares authorized to issue (in shares)	500,000,000	500,000,000
Par value of authorized common stock share (in dollars per share)	$ 1	$ 1
Number of common stock shares issued (in shares)	250,591,610	249,361,340
Number of shares in treasury (in shares)	67,000,487	62,885,348
Number of common stock shares repurchased in open market (in shares)	4,034,973	2,335,500
Share repurchased from the holders of employee stock options or stock appreciation rights (in shares)	80,166	82,455
Total of shares repurchased (in shares)	4,115,139	2,417,955
Average price, in open market, per common stock share (in dollars per share)	$ 58.93	$ 51.10
Number of common shares initially authorized in May 2007 for repurchase (in shares)		10,000,000
Remaining number of common shares available for repurchase (in shares)	2,500,000	6,600,000	8,900,000