Earnings Per Share - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 27, 2021	Jun. 28, 2020	Jun. 27, 2021	Jun. 28, 2020
Basic
Net earnings (loss) attributable to Hasbro, Inc.	$ (22.9)	$ (33.9)	$ 93.3	$ (103.6)
Average shares outstanding, basic (in shares)	137.8	137.2	137.8	137.2
Net earnings per common share, basic (in dollars per share)	$ (0.17)	$ (0.25)	$ 0.68	$ (0.75)
Diluted
Net earnings (loss) attributable to Hasbro, Inc.	$ (22.9)	$ (33.9)	$ 93.3	$ (103.6)
Effect of dilutive securities:
Average shares outstanding, basic (in shares)	137.8	137.2	137.8	137.2
Options and other share-based awards (in shares)	0.0	0.0	0.4	0.0
Equivalent Shares (in shares)	137.8	137.2	138.2	137.2
Net earnings per common share, diluted (in dollars per share)	$ (0.17)	$ (0.25)	$ 0.68	$ (0.75)