Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands				12 Months Ended
	Dec. 08, 2020	Jul. 19, 2019	May 03, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2018
Stockholders Equity Note Disclosure [Line Items]
Common stock, shares issued	1,725,000	1,587,000	3,144,531	55,557,698	55,321,457
Common stock issue price per share	$ 181.00	$ 87.00	$ 64.00
Exercised number of shares				86,980
Net proceeds from public offering	$ 297,800	$ 131,100	$ 189,600	$ 0	$ 0	$ 297,775
Stock-based compensation expense				$ 27,316	$ 27,500	17,007
Stock options, outstanding				609,965	625,107
Restricted stock units, outstanding				531,034	606,685
Aggregate intrinsic value of stock options exercised				$ 14,100	$ 20,300	$ 36,600
Weighted average grant date fair value of share-based awards granted				$ 87.40	$ 88.01	$ 53.06
Total fair value of stock options vested				$ 3,100	$ 3,000	$ 2,800
Weighted average grant date fair value of restricted stock units granted				$ 191.61
Total unrecognized compensation cost				$ 63,900
Unrecognized compensation cost, weighted average remaining requisite service period				3 years 3 days
Number of unvested options and restricted stock units				2,071,467
Incentive options, term				10 years
2018 Plan
Stockholders Equity Note Disclosure [Line Items]
Common stock shares reserved for Issuance							2,778,000
Incentive options, vesting period				1,904,702
Employee Stock Option | Minimum
Stockholders Equity Note Disclosure [Line Items]
Incentive options, vesting period				3 years
Employee Stock Option | Minimum | Vest Over Three Year
Stockholders Equity Note Disclosure [Line Items]
Incentive options, vesting percentage				20.00%
Employee Stock Option | Maximum
Stockholders Equity Note Disclosure [Line Items]
Incentive options, vesting period				5 years
Employee Stock Option | Maximum | Vest Over Five Year
Stockholders Equity Note Disclosure [Line Items]
Incentive options, vesting percentage				33.00%
Restricted Stock Units (RSUs)
Stockholders Equity Note Disclosure [Line Items]
Closing price of common stock				$ 169.31
Unvested Options [Member]
Stockholders Equity Note Disclosure [Line Items]
Incentive options, vesting period				5 years
Restricted Stock And Performance Stock Units [Member]
Stockholders Equity Note Disclosure [Line Items]
Restricted stock units, outstanding				531,034
Aggregate intrinsic value of restricted stock units vested				$ 43,900	46,500	28,300
Total grant date fair value of restricted stock units vested				$ 22,700	$ 13,900	$ 10,850
Non Employee Director Stock Option[Member]
Stockholders Equity Note Disclosure [Line Items]
Estimated forfeiture rates				0.00%
Incentive options, vesting period				9 years
Underwriters | Common Stock
Stockholders Equity Note Disclosure [Line Items]
Exercised number of shares	225,000	207,000	410,156
Non-Executive [Member] | Employee Stock Option
Stockholders Equity Note Disclosure [Line Items]
Estimated forfeiture rates				8.00%
Non-Executive [Member] | Restricted Stock And Performance Stock Units [Member]
Stockholders Equity Note Disclosure [Line Items]
Estimated forfeiture rates				8.00%
Executive Officer [Member] | Employee Stock Option
Stockholders Equity Note Disclosure [Line Items]
Estimated forfeiture rates				3.00%
Executive Officer [Member] | Restricted Stock And Performance Stock Units [Member]
Stockholders Equity Note Disclosure [Line Items]
Estimated forfeiture rates				3.00%