Business Combination - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 30, 2019	Nov. 30, 2019	Sep. 26, 2021	Sep. 27, 2020	Sep. 26, 2021	Sep. 27, 2020	Dec. 27, 2020	Jun. 27, 2021
Business Acquisition [Line Items]
Goodwill			$ 3,420,200,000	$ 3,644,100,000	$ 3,420,200,000	$ 3,644,100,000	$ 3,691,700,000	$ 3,420,200,000
Acquisition and related costs			0	5,900,000	0	166,000,000.0
Severance expense						11,500,000
Entertainment
Business Acquisition [Line Items]
Goodwill							2,252,900,000	$ 1,527,700,000
Senior Notes
Business Acquisition [Line Items]
Aggregate principal amount		$ 2,400,000,000
eOne
Business Acquisition [Line Items]
Aggregate purchase price	$ 4,600,000,000
Cash consideration for shares outstanding	3,800,000,000
Aggregate purchase price, extinguishment of debt	800,000,000
Shares issued as consideration (in shares)		10.6
Shares issued for acquisition, value		$ 975,200,000
Amortization expense of intangibles			$ 19,700,000	24,700,000	$ 66,400,000	72,300,000
Goodwill	3,200,000,000
Integration related costs				4,600,000		104,300,000
Integration related costs, acceleration of stock-based compensation						47,400,000
Integration related costs, advisor fees						38,200,000
Restructuring and related cost				1,400,000		61,700,000
Severance expense				$ 1,400,000		20,800,000	$ 32,500,000
Asset impairments						40,900,000
eOne | Entertainment
Business Acquisition [Line Items]
Acquisition and related costs						$ 98,500,000
eOne | Films and Television Programs
Business Acquisition [Line Items]
Investments in productions and content	$ 564,800,000
eOne | Titles
Business Acquisition [Line Items]
Threshold years for amortization method	3 years
eOne | Minimum | Trademarks and Trade Names
Business Acquisition [Line Items]
Intangible asset useful life	7 years
eOne | Maximum | Trademarks and Trade Names
Business Acquisition [Line Items]
Intangible asset useful life	15 years
eOne | Maximum | Titles Over 3 Years Old
Business Acquisition [Line Items]
Intangible asset useful life	10 years
eOne | Unsecured Committed
Business Acquisition [Line Items]
Cash consideration per share (in dollars and GBP per share)		$ 95.00
Term loans proceeds which financed acquisition	$ 1,000,000,000.0
eOne | Senior Notes
Business Acquisition [Line Items]
Aggregate principal amount		$ 2,400,000,000