Share Repurchase Program and Treasury Stock (Details) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Share Repurchase Program and Treasury Stock (Textuals) [Abstract]
Authorized amount under share repurchase program	$ 2,250,000,000
Remaining Amount to Repurchase under the program	508,200,000
Shares Purchased Under Share Repurchase Program	19,700,000
Treasury Stock, Value, Acquired, Cost Method	$ 207,850,000	$ 171,200,000	$ 204,578,000
Number of shares repurchased	1,241,359	1,061,666
Average price of share repurchased, per share	$ 167.42	$ 161.22
Exercise of stock options and restricted stock units, shares reissued	295,090	220,463