Share-Based Compensation - Share-Based Payment Award Activity (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2020 USD ($) $ / shares shares	Sep. 30, 2020 USD ($) $ / shares shares
Options
Outstanding, beginning of period, in shares | shares		625,407
Granted, in shares | shares		123,301
Exercised, in shares | shares		(130,330)
Forfeited, in shares | shares		(15,460)
Expired, in shares | shares	(1,030)
Outstanding, end of period, in shares | shares	601,888	601,888
Vested and expected to vest, end of period, in shares | shares	578,024	578,024
Exercisable, end of period, in shares | shares	317,896	317,896
Weighted Average Exercise Price
Outstanding, beginning of period, in usd per share | $ / shares		$ 169.33
Granted, in usd per share | $ / shares		186.83
Exercised, in usd per share | $ / shares		99.72
Forfeited, in usd per share | $ / shares		231.75
Expired, in usd per share | $ / shares	$ 71.11
Outstanding, end of period, in usd per share | $ / shares	186.55	186.55
Vested and expected to vest, end of period, in usd per share | $ / shares	185.26	185.26
Exercisable, end of period, in usd per share | $ / shares	$ 152.61	$ 152.61
Weighted Average Remaining Contractual Life - in Years
Outstanding, end of period		4 years 29 days
Vested and expected to vest, end of period		4 years
Exercisable, end of period		2 years 7 months 2 days
Aggregate Intrinsic Value of In-The-Money Options
Outstanding, end of period | $	$ 38,405,994	$ 38,405,994
Vested and expected to vest, end of period | $	37,654,264	37,654,264
Exercisable, end of period | $	$ 30,524,026	$ 30,524,026