Segment Reporting - Net Revenues by Product Category (Details) - USD ($) $ 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
Revenue from External Customer [Line Items]
Net revenues	$ 1,722,971	$ 1,776,623	$ 860,279	$ 1,105,570	$ 1,428,007	$ 1,575,173	$ 984,537	$ 732,510	$ 5,465,443	$ 4,720,227	$ 4,579,646
Franchise Brands
Revenue from External Customer [Line Items]
Net revenues									2,286,079	2,411,847	2,445,902
Partner Brands
Revenue from External Customer [Line Items]
Net revenues									1,079,355	1,220,982	987,283
Hasbro Gaming
Revenue from External Customer [Line Items]
Net revenues									814,798	709,750	787,692
Emerging Brands
Revenue from External Customer [Line Items]
Net revenues									480,371	377,648	358,769
TV/Film/Entertainment
Revenue from External Customer [Line Items]
Net revenues									$ 804,840	$ 0	$ 0