Collaboration Agreements and Business Development Activities - Collaboration Revenues under the Collaboration Agreement with Takeda (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 02, 2026	Jan. 03, 2025	Dec. 29, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 2,320,126	$ 2,168,701	$ 1,830,208
Collaborative arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	19,177	21,370	34,214
License revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	214,375	349,244	178,635
License revenues | Collaborative arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	20,125	12,915	20,671
Collaboration services revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	(17,053)	10,062	22,694
Collaboration services revenues | Collaborative arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ (948)	$ 8,455	$ 13,543