Segment Reporting - Net Revenues by Brand and Entertainment Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2021	Sep. 27, 2020	Sep. 26, 2021	Sep. 27, 2020
Revenue from External Customer [Line Items]
Net revenues	$ 1,970.0	$ 1,776.6	$ 4,407.0	$ 3,742.5
Franchise Brands
Revenue from External Customer [Line Items]
Net revenues	882.0	807.5	2,023.4	1,580.9
Partner Brands
Revenue from External Customer [Line Items]
Net revenues	366.7	409.2	766.7	729.8
Hasbro Gaming
Revenue from External Customer [Line Items]
Net revenues	281.9	239.2	565.3	516.3
Emerging Brands
Revenue from External Customer [Line Items]
Net revenues	177.5	155.0	399.2	325.1
TV/Film/Entertainment
Revenue from External Customer [Line Items]
Net revenues	261.9	165.7	652.4	590.4
Gaming including Magic the Gathering and Monopoly
Revenue from External Customer [Line Items]
Net revenues	658.6	543.1	1,543.3	1,202.6
Entertainment
Revenue from External Customer [Line Items]
Net revenues	327.1	185.4	772.5	662.0
Entertainment | Film & TV
Revenue from External Customer [Line Items]
Net revenues	255.4	141.6	586.1	514.5
Entertainment | Family Brands
Revenue from External Customer [Line Items]
Net revenues	60.5	14.2	105.4	58.9
Entertainment | Music and Other
Revenue from External Customer [Line Items]
Net revenues	$ 11.2	$ 29.6	$ 81.0	$ 88.6