Summary of Significant Accounting Policies - Schedule of Earnings per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 27, 2020	Sep. 27, 2020	Jun. 28, 2020	Mar. 29, 2020	Dec. 29, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 27, 2020	Dec. 29, 2019	Dec. 30, 2018
Net earnings
Net earnings attributable to Hasbro, Inc.	$ 105,173	$ 220,898	$ (33,915)	$ (69,637)	$ 267,345	$ 212,949	$ 13,433	$ 26,727	$ 222,519	$ 520,454	$ 220,434
Average shares outstanding, basic and diluted (in shares)									137,260	127,896	126,132
Earnings Per Share, Basic [Abstract]
Equivalent shares (in shares)									137,260	127,896	126,132
Net earnings attributable to Hasbro, Inc. (in dollars per share)	$ 0.77	$ 1.61	$ (0.25)	$ (0.51)	$ 2.02	$ 1.68	$ 0.11	$ 0.21	$ 1.62	$ 4.07	$ 1.75
Effect of dilutive securities:
Options and other share-based awards (in shares)									294	603	758
Equivalent shares (in shares)									137,554	128,499	126,890
Net earnings attributable to Hasbro, Inc. (in dollars per share)	$ 0.76	$ 1.61	$ (0.25)	$ (0.51)	$ 2.01	$ 1.67	$ 0.11	$ 0.21	$ 1.62	$ 4.05	$ 1.74