Goodwill and Intangibles - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Sep. 26, 2021	Sep. 27, 2020	Jun. 28, 2020	Mar. 29, 2020	Dec. 26, 2021	Dec. 27, 2020	Dec. 29, 2019
Business Acquisition [Line Items]
Payments to acquire businesses, gross					$ 0	$ 33,085	$ 0
Goodwill					166,360	$ 171,657	$ 138,674
Listen In Audio, Inc.
Business Acquisition [Line Items]
Business combination, consideration transferred				$ 8,600
Payments to acquire businesses, gross				8,000
Payments to acquire business, note receivable				$ 600
Business acquisition, retention payment term (in years)				3 years
Goodwill			$ 5,800
Intangible assets, carrying value			$ 2,700
Estimated useful life of intangible assets acquired (in years)			8 years
Serial Productions, LLC
Business Acquisition [Line Items]
Payments to acquire businesses, gross		$ 25,000
Goodwill		21,500
Intangible assets, carrying value		12,900
Estimated useful life of intangible assets acquired (in years)	6 years
Earn-out payments		$ 9,300
Earn-out payment term (in years)		5 years
Intangible assets (excluding goodwill)					9,000
Miscellaneous Assets
Business Acquisition [Line Items]
Intangible assets, carrying value					$ 14,200
Minimum
Business Acquisition [Line Items]
Estimated useful life of intangible assets acquired (in years)					5 years
Maximum
Business Acquisition [Line Items]
Estimated useful life of intangible assets acquired (in years)					8 years