Organization and Significant Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Jan. 02, 2024	Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2023
Organization And Significant Accounting Policies [Line Items]
Cash, cash equivalents and restricted cash		$ 58,200
Restricted cash		6,900
Available-for-sale securities, at fair value		162,064		$ 292,735
Increase (decrease) in cash and investments		(183,300)
Development regulatory and sales milestones payments		2,800,000
Income tax (benefit) expense		(3,313)	$ 17
Subsequent Event | Underwriting Agreement
Organization And Significant Accounting Policies [Line Items]
Shares of common stock issued (in shares)	15,790,000
Common stock offering price (in dollars per share)	$ 28.50
Aggregate purchase price paid by investors	$ 450,000
Net proceeds	$ 429,000
Royalty Pharma
Organization And Significant Accounting Policies [Line Items]
Upfront milestone payment received		$ 250,000