Revenue - Schedule of Revenues Disaggregated by Revenue Source and Segment (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2023	Sep. 30, 2023	Jul. 01, 2023	Apr. 01, 2023	Dec. 31, 2022	Oct. 01, 2022	Jul. 02, 2022	Apr. 02, 2022	Dec. 30, 2023	Dec. 31, 2022	Jan. 01, 2022
Disaggregation Of Revenue [Line Items]
Revenues, net	$ 205,955	$ 214,871	$ 226,830	$ 241,895	$ 222,902	$ 249,718	$ 269,454	$ 297,761	$ 889,551	$ 1,039,835	$ 1,211,165
North America
Disaggregation Of Revenue [Line Items]
Revenues, net									638,196	727,358	815,444
International
Disaggregation Of Revenue [Line Items]
Revenues, net									251,355	312,477	395,721
Digital Subscription Revenues
Disaggregation Of Revenue [Line Items]
Revenues, net									571,074	662,668	786,563
Digital Subscription Revenues | North America
Disaggregation Of Revenue [Line Items]
Revenues, net									374,004	436,148	502,866
Digital Subscription Revenues | International
Disaggregation Of Revenue [Line Items]
Revenues, net									197,070	226,520	283,697
Workshops + Digital Fees
Disaggregation Of Revenue [Line Items]
Revenues, net									221,139	256,387	274,866
Workshops + Digital Fees | North America
Disaggregation Of Revenue [Line Items]
Revenues, net									179,054	204,115	210,076
Workshops + Digital Fees | International
Disaggregation Of Revenue [Line Items]
Revenues, net									42,085	52,272	64,790
Clinical Subscription Revenues
Disaggregation Of Revenue [Line Items]
Revenues, net									30,542
Clinical Subscription Revenues | North America
Disaggregation Of Revenue [Line Items]
Revenues, net									30,542
Subscription Revenues, net
Disaggregation Of Revenue [Line Items]
Revenues, net									822,755	919,055	1,061,429
Subscription Revenues, net | North America
Disaggregation Of Revenue [Line Items]
Revenues, net									583,600	640,263	712,942
Subscription Revenues, net | International
Disaggregation Of Revenue [Line Items]
Revenues, net									239,155	278,792	348,487
Product sales and other, net
Disaggregation Of Revenue [Line Items]
Revenues, net									66,796	120,780	149,736
Product sales and other, net | North America
Disaggregation Of Revenue [Line Items]
Revenues, net									54,596	87,095	102,502
Product sales and other, net | International
Disaggregation Of Revenue [Line Items]
Revenues, net									$ 12,200	$ 33,685	$ 47,234