Stockholders' Equity - Additional Information (Detail) - USD ($)								1 Months Ended				3 Months Ended	12 Months Ended
	Dec. 02, 2022	Jul. 02, 2021	Jun. 29, 2021	Dec. 04, 2020	Dec. 01, 2020	Jun. 05, 2020	Jun. 01, 2020	Nov. 30, 2022	Mar. 31, 2022	May 31, 2020	Aug. 31, 2019	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock, par value													$ 0.0001	$ 0.0001
Weighted Average Remaining Contractual Term, Exercisable													6 years 9 months 21 days
Common Stock, Par or Stated Value Per Share													$ 0.0001	$ 0.0001
Regeneron Pharmaceuticals Inc. [Member]
Class Of Stock [Line Items]
Proceeds from common stock offering													$ 0	$ 0	$ 12,580,000
Issuance of common stock															12,580,000
Follow On Public Offering
Class Of Stock [Line Items]
Proceeds from common stock offering													337,892,000	648,315,000	296,607,000
Issuance of common stock													337,892,000	$ 648,315,000	$ 296,607,000
2019 Sales Agreement [Member]
Class Of Stock [Line Items]
Stock Issued During Period, Shares, New Issues												579,788		641,709	2,270,161
Common stock price per share									$ 69.43			$ 69.43		$ 72.79	$ 22.53
Proceeds from common stock offering													38,900,000	$ 45,300,000	$ 49,500
Percentage of gross proceeds from common stock as sales agent cash commission											3.00%
Shares Issued, Price Per Share									$ 69.43			$ 69.43		$ 72.79	$ 22.53
2019 Sales Agreement [Member] | General and Administrative Expenses [Member]
Class Of Stock [Line Items]
Legal accounting and other fees													$ 200,000	$ 100,000	$ 200,000
2019 Sales Agreement [Member] | Maximum [Member]
Class Of Stock [Line Items]
Proceeds from common stock offering											$ 150,000,000.0
2020 Stock Purchase Agreement [Member] | Private Placement [Member] | Regeneron Pharmaceuticals Inc. [Member]
Class Of Stock [Line Items]
Stock Issued During Period, Shares, New Issues										925,218
Common stock, par value										$ 0.0001
Cash consideration received on sale of common stock										$ 30,000,000.0
Sale of stock, price per share										$ 32.42
Percentage of premium over volume-weighted average trading price of common stock during 30-day period prior to closing of equity transaction										100.00%
Issuance of common stock										$ 12,600,000
Sale of Stock, Consideration Received on Transaction										$ 30,000,000.0
Common Stock, Par or Stated Value Per Share										$ 0.0001
2022 Sales Agreement [Member]
Class Of Stock [Line Items]
Stock Issued During Period, Shares, New Issues													3,395,339
Common stock price per share													$ 57.43
Proceeds from common stock offering													$ 189,000,000.0
Percentage of gross proceeds from common stock as sales agent cash commission									3.00%
Proceeds from common stock offering													$ 205,000,000.0
Shares Issued, Price Per Share													$ 57.43
2022 Sales Agreement [Member] | General and Administrative Expenses [Member]
Class Of Stock [Line Items]
Legal accounting and other fees													$ 100,000
2022 Sales Agreement [Member] | Maximum [Member]
Class Of Stock [Line Items]
Proceeds from common stock offering									$ 400,000,000.0
Underwriting Agreement [Member] | Follow On Public Offering
Class Of Stock [Line Items]
Stock Issued During Period, Shares, New Issues			4,758,620		5,513,699		6,301,370	6,550,219
Common stock, par value			$ 0.0001		$ 0.0001		$ 0.0001	$ 0.0001
Shares available for future issuance			620,689		719,178		821,917	982,532
Common stock price per share			$ 145.00		$ 36.50		$ 18.25	$ 45.80
Weighted Average Remaining Contractual Term, Exercisable								30 days
Proceeds from common stock offering	$ 337,900,000	$ 648,300,000		$ 188,900,000		$ 107,700,000
Shares Issued, Price Per Share			145.00		36.50		18.25	$ 45.80
Common Stock, Par or Stated Value Per Share			$ 0.0001		$ 0.0001		$ 0.0001	$ 0.0001