Share-Based Compensation and Benefit Plans (Summary Of Stock Options) (Details) - Stock option [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-Based Compensation and Benefit Plans
Exercisable at the end of the year, average remaining contractual term	3 years 10 months 14 days	4 years 2 months 5 days	4 years 6 months 21 days
Employee stock option [Member]
Share-Based Compensation and Benefit Plans
Outstanding beginning balance, shares	3,291
Outstanding at the beginning of the year, weighted-average exercise price	$ 81.04
Granted, shares	308
Granted, weighted-average exercise price	$ 267.00
Exercised, shares	(751)
Exercised, weighted-average exercise price	$ 62.81
Forfeited, shares	(59)
Forfeited, weighted-average exercise price	$ 144.91
Outstanding ending balance, shares	2,789	3,291
Outstanding at the end of the year, weighted-average exercise price	$ 105.11	$ 81.04
Outstanding at the end of the year, average remaining contractual term	5 years 1 month 3 days
Outstanding at the end of the year, aggregate intrinsic value	$ 483,331
Vested or expected to vest at the end of the year, shares	2,744
Vested or expected to vest at the end of the year, weighted-average exercise price	$ 103.29
Vested or expected to vest at the end of the year, average remaining contractual term	5 years 13 days
Vested or expected to vest at the end of the year, aggregate intrinsic value	$ 480,582
Exercisable at the end of the year, shares	2,027
Exercisable at the end of the year, weighted-average exercise price	$ 65.45
Exercisable at the end of the year, average remaining contractual term	3 years 10 months 21 days
Exercisable at the end of the year, aggregate intrinsic value	$ 431,637
Director [Member]
Share-Based Compensation and Benefit Plans
Outstanding beginning balance, shares	17
Outstanding at the beginning of the year, weighted-average exercise price	$ 45.13
Granted, shares	0
Granted, weighted-average exercise price	$ 0.00
Exercised, shares	(6)
Exercised, weighted-average exercise price	$ 39.99
Forfeited, shares	0
Forfeited, weighted-average exercise price	$ 0.00
Outstanding ending balance, shares	11	17
Outstanding at the end of the year, weighted-average exercise price	$ 48.31	$ 45.13
Outstanding at the end of the year, average remaining contractual term	4 months 3 days
Outstanding at the end of the year, aggregate intrinsic value	$ 2,416
Vested or expected to vest at the end of the year, shares	11
Vested or expected to vest at the end of the year, weighted-average exercise price	$ 48.31
Vested or expected to vest at the end of the year, average remaining contractual term	4 months 3 days
Vested or expected to vest at the end of the year, aggregate intrinsic value	$ 2,416
Exercisable at the end of the year, shares	11
Exercisable at the end of the year, weighted-average exercise price	$ 48.31
Exercisable at the end of the year, average remaining contractual term	4 months 3 days
Exercisable at the end of the year, aggregate intrinsic value	$ 2,416