Share-Based Employee Compensation Plans and Other Compensation and Benefit Plans (Stock Option Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Vesting of options, description	The Company's stock-based incentive plans provide for the granting of stock options for the purchase of common stock of the Company to directors and certain key employees of the Company. Options are granted at an exercise price that is equal to the closing market price of the Company's common stock on the date of the grant. Director options granted under the plans expire after seven years and are fully vested after six months. Employee options granted under the plans expire after ten years and typically vest 25% per year, over four years. The Company records compensation expense for the grant date fair value of the option awards, adjusted for estimated forfeitures, evenly over the vesting period.
Weighted-average grant date fair value of options awarded	$ 23.88	$ 16.26
Remaining unrecognized compensation expense	$ 50.7
Weighted-average period for cost recognition, years	2 years 11 months 26 days
Employee Stock Option [Member]
Options expiration date, years	10 years
Vesting period	4 years
Option vesting rate per year	25.00%
Stock Option [Member] | Director [Member]
Options expiration date, years	7 years
Vesting period	6 months