Business Combination - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions		1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 30, 2019	Nov. 30, 2019	Jun. 27, 2021	Jun. 28, 2020	Jun. 27, 2021	Jun. 28, 2020	Dec. 27, 2020
Business Acquisition [Line Items]
Goodwill			$ 3,420,800,000	$ 3,666,000,000.0	$ 3,420,800,000	$ 3,666,000,000.0	$ 3,691,700,000
Acquisition and related costs			0	10,300,000	0	160,100,000
Severance expense				11,500,000
Entertainment
Business Acquisition [Line Items]
Goodwill			1,528,000,000.0		1,528,000,000.0		2,252,900,000
Senior Notes | Senior Unsecured 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			$ 21,800,000	22,600,000	$ 46,700,000	47,600,000
Goodwill	3,200,000,000
Integration related costs				4,000,000.0		99,700,000
Integration related costs, acceleration of stock-based compensation						47,400,000
Integration related costs, advisor fees						38,200,000
Restructuring and related cost				6,300,000		60,400,000
Severance expense				$ 6,300,000		19,500,000	$ 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 | Senior Unsecured Notes
Business Acquisition [Line Items]
Aggregate principal amount		$ 2,400,000,000