Share-Based Compensation (Information Concerning Currently Outstanding and Exercisable Options) (Details)	12 Months Ended
	Dec. 31, 2019 $ / shares shares
20.01 - 30.00 [Member]
Number of options outstanding, in shares | shares	42,296
Weighted average remaining life, Outstanding, in years	1 year
Weighted average exercise price, options outstanding, in dollars per share | $ / shares	$ 24.72
Number of options exercisable, in shares | shares	42,296
Weighted average remaining life, Exercisable, in years	1 year
Weighted average exercise price, option exercisable, in dollars per share | $ / shares	$ 24.72
30.01 - 40.00 [Member]
Number of options outstanding, in shares | shares	140,778
Weighted average remaining life, Outstanding, in years	1 year 8 months 12 days
Weighted average exercise price, options outstanding, in dollars per share | $ / shares	$ 34.07
Number of options exercisable, in shares | shares	140,778
Weighted average remaining life, Exercisable, in years	1 year 8 months 12 days
Weighted average exercise price, option exercisable, in dollars per share | $ / shares	$ 34.07
40.01 - 50.00 [Member]
Number of options outstanding, in shares | shares	820,185
Weighted average remaining life, Outstanding, in years	5 years
Weighted average exercise price, options outstanding, in dollars per share | $ / shares	$ 48.46
Number of options exercisable, in shares | shares	820,185
Weighted average remaining life, Exercisable, in years	5 years
Weighted average exercise price, option exercisable, in dollars per share | $ / shares	$ 48.46
50.01 - 60.00 [Member]
Number of options outstanding, in shares | shares	291,706
Weighted average remaining life, Outstanding, in years	3 years 10 months 24 days
Weighted average exercise price, options outstanding, in dollars per share | $ / shares	$ 59.41
Number of options exercisable, in shares | shares	291,706
Weighted average remaining life, Exercisable, in years	3 years 10 months 24 days
Weighted average exercise price, option exercisable, in dollars per share | $ / shares	$ 59.41
Sixty point zero one dollars to seventy dollars [Member]
Number of options outstanding, in shares | shares	417,212
Weighted average remaining life, Outstanding, in years	4 years 8 months 12 days
Weighted average exercise price, options outstanding, in dollars per share | $ / shares	$ 66.99
Number of options exercisable, in shares | shares	417,212
Weighted average remaining life, Exercisable, in years	4 years 8 months 12 days
Weighted average exercise price, option exercisable, in dollars per share | $ / shares	$ 66.99
Seventy point zero one dollars to eighty dollars [Domain]
Number of options outstanding, in shares | shares	14,031
Weighted average remaining life, Outstanding, in years	7 years
Weighted average exercise price, options outstanding, in dollars per share | $ / shares	$ 75.67
Number of options exercisable, in shares | shares	0
Weighted average remaining life, Exercisable, in years	0 years
Weighted average exercise price, option exercisable, in dollars per share | $ / shares	$ 0
Eighty point zero one dollars to ninety dollars [Domain]
Number of options outstanding, in shares | shares	1,228,171
Weighted average remaining life, Outstanding, in years	6 years 9 months 18 days
Weighted average exercise price, options outstanding, in dollars per share | $ / shares	$ 80.84
Number of options exercisable, in shares | shares	638,735
Weighted average remaining life, Exercisable, in years	6 years 7 months 6 days
Weighted average exercise price, option exercisable, in dollars per share | $ / shares	$ 80.33
Ninety point zero one dollars to one hundred dollars [Domain]
Number of options outstanding, in shares | shares	1,242,338
Weighted average remaining life, Outstanding, in years	7 years 9 months 18 days
Weighted average exercise price, options outstanding, in dollars per share | $ / shares	$ 90.12
Number of options exercisable, in shares | shares	334,982
Weighted average remaining life, Exercisable, in years	7 years 9 months 18 days
Weighted average exercise price, option exercisable, in dollars per share | $ / shares	$ 90.07
One hundred point one dollars to one hundred ten dollars [Domain]
Number of options outstanding, in shares | shares	1,193,089
Weighted average remaining life, Outstanding, in years	8 years 10 months 24 days
Weighted average exercise price, options outstanding, in dollars per share | $ / shares	$ 101.29
Number of options exercisable, in shares | shares	4,029
Weighted average remaining life, Exercisable, in years	7 years 10 months 24 days
Weighted average exercise price, option exercisable, in dollars per share | $ / shares	$ 101.22
One hundred ten point one dollars to one hundred twenty five dollars [Domain]
Number of options outstanding, in shares | shares	29,440
Weighted average remaining life, Outstanding, in years	9 years 6 months
Weighted average exercise price, options outstanding, in dollars per share | $ / shares	$ 122.34
Number of options exercisable, in shares | shares	0
Weighted average remaining life, Exercisable, in years	0 years
Weighted average exercise price, option exercisable, in dollars per share | $ / shares	$ 0
Twenty four point twenty three dollars to one hundred twenty four point ninety five dollars [Member]
Number of options outstanding, in shares | shares	5,419,246
Weighted average remaining life, Outstanding, in years	6 years 9 months 18 days
Weighted average exercise price, options outstanding, in dollars per share | $ / shares	$ 78.91
Number of options exercisable, in shares | shares	2,689,923
Weighted average remaining life, Exercisable, in years	5 years 4 months 24 days
Weighted average exercise price, option exercisable, in dollars per share | $ / shares	$ 64.22