Segment Reporting - Net Revenues by Brand Portfolio (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 26, 2021	Dec. 27, 2020	Dec. 29, 2019
Revenue from External Customer [Line Items]
Net revenues	$ 6,420.4	$ 5,465.4	$ 4,720.2
Franchise Brands
Revenue from External Customer [Line Items]
Net revenues	2,792.7	2,286.1	2,411.8
Partner Brands
Revenue from External Customer [Line Items]
Net revenues	1,161.0	1,079.4	1,221.0
Hasbro Gaming
Revenue from External Customer [Line Items]
Net revenues	851.4	814.8	709.8
Emerging Brands
Revenue from External Customer [Line Items]
Net revenues	617.6	480.4	377.6
TV/Film/Entertainment
Revenue from External Customer [Line Items]
Net revenues	$ 997.7	$ 804.7	$ 0.0