Stock-Based Compensation Plans (Details 1) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, Shares	2,514,095	2,322,845
Weighted Average Exercise Price, Beginning balance	$ 44.10	$ 38.19
Granted, Shares	5,000	500,006
Weighted Average Exercise Price, Granted	$ 64.90	$ 64.73
Exercised, Shares	(85,848)	(364,153)
Weighted Average Exercise Price, Exercised	$ 29.88	$ 31.52
Canceled or expired, Shares	(17,692)	(43,143)
Weighted Average Exercise Price, Canceled or expired	$ 50.03	$ 43.12
Ending balance, Shares	2,415,555	2,415,555
Weighted Average Exercise Price, Ending Balance	$ 44.60	$ 44.60
Options exercisable at end of period, Shares	1,501,517	1,501,517
Weighted Average Exercise Price, Options exercisable at end of period	$ 37.61	$ 37.61
Non-Employee Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, Shares	410,504	404,692
Weighted Average Exercise Price, Beginning balance	$ 36.80	$ 32.85
Granted, Shares	5,476	42,767
Weighted Average Exercise Price, Granted	$ 49.28	$ 59.48
Exercised, Shares	(10,511)	(41,990)
Weighted Average Exercise Price, Exercised	$ 26.07	$ 17.54
Ending balance, Shares	405,469	405,469
Weighted Average Exercise Price, Ending Balance	$ 37.24	$ 37.24
Options exercisable at end of period, Shares	361,896	361,896
Weighted Average Exercise Price, Options exercisable at end of period	$ 34.61	$ 34.61