Stock-based Compensation - Stock Option (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Maximum
Stock-based compensation expense
Expiration period	10 years
Stock options
Stock-based compensation expense
Options outstanding to purchase of common stock	2,301,574	1,837,540
Shares available for future issuance	1,661,293
Shares
Outstanding at the beginning of the year (in shares)	1,837,540
Options granted (in shares)	687,059
Options exercised (in shares)	(11,080)
Options cancelled (in shares)	(211,945)
Outstanding at the end of the year (in shares)	2,301,574	1,837,540
Exercisable at the end of the year (in shares)	1,432,144
Weighted average exercise price
Outstanding at the beginning of the year (in dollars per share)	$ 71.80
Options granted (in dollars per share)	109.03
Options exercised (in dollars per share)	92.96
Options cancelled (in dollars per share)	114.34
Outstanding at the end of the year (in dollars per share)	78.89	$ 71.80
Exercisable at the end of the year (in dollars per share)	$ 62.66
Weighted average remaining contractual life (years)
Outstanding at the end of the year	6 years 6 months 3 days
Exercisable at the end of the year	5 years 4 months 17 days
Aggregate intrinsic value
Outstanding at the end of the year	$ 62,566
Exercisable at the end of the year	60,932
Additional disclosures
Total intrinsic value of options exercised	100	$ 4,100	$ 2,200
Proceeds resulting from exercise of stock options	$ 1,000	$ 700	$ 200
Weighted-average grant date fair value of options (in dollars per share)	$ 73.29	$ 68.07	$ 91.19