Stockholders' Equity - Additional Information (Details)	1 Months Ended					3 Months Ended				9 Months Ended		12 Months Ended
	Jul. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($)	Aug. 31, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2024 USD ($) $ / shares shares	Jun. 30, 2024 USD ($) shares	Sep. 30, 2023 USD ($) shares	Jun. 30, 2023 shares	Sep. 30, 2024 USD ($) Vote $ / shares shares	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($) shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected cash dividend										$ 0
Expense						$ 21,660,000		$ 16,368,000		63,232,000	$ 43,705,000
Stock-based compensation expense capitalized						300,000		$ 900,000		1,000,000	2,400,000
Proceeds from Issuance of Common Stock										$ 24,365,000	$ 258,750,000
Common stock, voting right per share | Vote										1
Weighted average grant date fair value | $ / shares										$ 64.54
Unrecognized compensation cost related to non-vested stock options expected to be recognized						$ 160,900,000				$ 160,900,000
Expected vesting period for non-vested share-based compensation										2 years 6 months
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock | shares						148,260	148,875	450,000	3,000,000
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period										4 years
Compensation cost not yet recognized related to unvested RSUs						$ 43,400,000				$ 43,400,000
Weighted average contractual term										2 years 7 months 6 days
Intrinsic value lapsed						$ 8,900,000				$ 8,900,000
2015 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future grant | shares						3,058,009				3,058,009
June 2023 Public Offering
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from Issuance of Common Stock	$ 31,700,000									$ 211,300,000
Underwriting discounts and commissions	$ 2,000,000					$ 13,500,000				13,500,000
Other offering costs										$ 200,000
June 2023 Public Offering | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share Price | $ / shares	$ 75					$ 75				$ 75
Issuance of common stock | shares	450,000									3,000,000
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued | shares										52,368
Purchase price of common stock percent										85.00%
Expense						$ 400,000				$ 1,200,000
March 2022 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from issuance of common stock, gross							$ 11,300,000			$ 13,100,000
Shares issued | shares							148,875			148,260
Proceeds from issuance of common stock, net							$ 11,000,000			$ 12,800,000
Leerink | December 2019 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from issuance of common stock, gross														$ 7,400,000
Shares issued | shares														110,296
Proceeds from issuance of common stock, net														$ 7,200,000
Common stock sales agreement, commission percentage				3.00%
Leerink | March 2022 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock sales agreement, authorized amount		$ 250,000,000
Proceeds from Issuance of Common Stock										$ 0		$ 0
Leerink | December 2019 and March 2022 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from issuance of common stock, gross													$ 238,800,000
Shares issued | shares													5,167,973
Proceeds from issuance of common stock, net													$ 231,800,000
Maximum | Leerink | December 2019 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock sales agreement, authorized amount					$ 80,000,000
Maximum | Leerink | March 2022 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock sales agreement, authorized amount			$ 250,000,000	$ 200,000,000
Common stock sales agreement, commission percentage			3.00%	3.00%
Hercules Capital Inc | March 2022 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued | shares										152,487
Proceeds from issuance of common stock, net										$ 5,000,000
Share Price | $ / shares						$ 32.79				$ 32.79