Acquisition - Fair value of the assets acquired and liabilities assumed (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Oct. 02, 2019	Mar. 31, 2020	Dec. 29, 2020	Dec. 31, 2019
Less net assets acquired:
Goodwill.			$ 1,451	$ 78,355
Impairment expense of acquired intangible assets			103,300
Acquisition-related costs			2,699	$ 5,270
Acquisition
Purchase consideration:
Cash at closing		$ 288,089
Assumption of debt previously owed by FRC		10,000
Deferred payments		53,471
Contingent consideration		12,786
Business Combination, Consideration Transferred, Total		364,346
Fair value of previously-held equity interests		122,000
Total		486,346
Less net assets acquired:
Current assets		23,682
Property and equipment		84,360
Intangible assets		336,280
Operating lease assets		223,455
Other assets		5,842
Current liabilities		(64,814)
Operating lease liabilities		(202,433)
Other noncurrent liabilities		(883)
Total net assets acquired		405,489
Goodwill.		$ 80,857
Goodwill impairment expense			79,400
Goodwill deductible for tax purpose			$ 74,200
Operating lease assets, weighted-average amortization period			15 years 2 months 12 days
Acquisition | Minimum
Less net assets acquired:
Property and equipment, useful lives			3 years
Acquisition | Maximum
Less net assets acquired:
Property and equipment, useful lives			30 years
North Italia Acquisition
Purchase consideration:
Fair value of previously-held equity interests	$ 122,000
Less net assets acquired:
Goodwill.			$ 29,200