Segment and Geographic Data - Sources of Revenue and Other Information by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Jan. 02, 2021		Sep. 26, 2020	Jun. 27, 2020	Mar. 28, 2020	Dec. 28, 2019		Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Jan. 02, 2021		Dec. 28, 2019		Dec. 29, 2018
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue	$ 323,427		$ 320,699	$ 333,637	$ 400,361	$ 332,583		$ 348,567	$ 369,023	$ 363,164	$ 1,378,124		$ 1,413,337		$ 1,514,121
Long-lived assets	51,935	[1]				54,066	[1]				51,935	[1]	54,066	[1]	52,202
Operating lease assets	119,102					151,983					119,102		151,983
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue											880,945		913,930		974,843
Long-lived assets	43,651	[1]				43,909	[1]				43,651	[1]	43,909	[1]	43,772
Operating lease assets	107,023					134,623					107,023		134,623
Canada
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue											61,155		65,372		72,408
Long-lived assets	4,508	[1]				4,997	[1]				4,508	[1]	4,997	[1]	4,825
Operating lease assets	6,136					9,270					6,136		9,270
Continental Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue											313,380		293,233		304,325
Long-lived assets	1,471	[1]				2,374	[1]				1,471	[1]	2,374	[1]	1,257
Operating lease assets	3,038					4,490					3,038		4,490
United Kingdom
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue											84,387		94,557		107,072
Long-lived assets	1,751	[1]				2,068	[1]				1,751	[1]	2,068	[1]	1,924
Operating lease assets	2,217					2,533					2,217		2,533
Other
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue											38,257		46,245		55,473
Long-lived assets	554	[1]				718	[1]				554	[1]	718	[1]	424
Operating lease assets	$ 688					$ 1,067					688		1,067
Digital Subscription Revenues
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue											743,060		609,996		567,767
Workshops + Digital Fees
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue											443,429		597,270		705,429
In-Studio Product Sales
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue											40,352		118,493		148,856
E-commerce, Licensing, Franchise Royalties and Other
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue											$ 151,283		$ 87,578		$ 92,069

[1] Amounts include finance lease assets