Business Combination - Supplemental Pro Forma Results of Operations (Details) - eOne Acquisition $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 29, 2019 USD ($) $ / shares
Business Acquisition [Line Items]
Revenues	$ 5,936.0
Net earnings	351.3
Net earnings attributable to Hasbro, Inc.	$ 345.9
Net earnings per common share attributable to Hasbro, Inc.: Diluted (in dollars per share) | $ / shares	$ 2.51
Net earnings per common share attributable to Hasbro, Inc.: Basic (in dollars per share) | $ / shares	$ 2.51