Share-Based Compensation and Benefit Plans (Stock Options) (Narrative) (Details) - Stock option [Member] - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Share-Based Compensation and Benefit Plans
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 or the minimum required service period.
Weighted-average grant-date fair value of options awarded	$ 64.00	$ 51.59
Remaining unrecognized compensation expense	$ 29.2
Weighted-average period for cost recognition	2 years 5 months 24 days
Employee stock option [Member]
Share-Based Compensation and Benefit Plans
Options expiration period	10 years
Vesting period	4 years
Option vesting rate per year	25.00%
Director [Member]
Share-Based Compensation and Benefit Plans
Options expiration period	7 years
Vesting period	6 months