Earnings Per Share - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 28, 2021	Mar. 29, 2020
Earnings Per Share [Abstract]
Net earnings (loss) attributable to Hasbro, Inc.	$ 116.2	$ (69.7)
Average shares outstanding (in shares)	137.7	137.1
Basic
Equivalent Shares (in shares)	137.7	137.1
Net earnings per common share (in dollars per share)	$ 0.84	$ (0.51)
Effect of dilutive securities:
Options and other share-based awards (in shares)	0.4	0.0
Equivalent Shares (in shares)	138.1	137.1
Net earnings per common share (in dollars per share)	$ 0.84	$ (0.51)