Weighted Average Assumptions Used in the Measurement of Benefit Obligations (Detail)	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.26%	4.31%	3.71%
Other Benefits | United States
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.80%	3.90%	3.30%
Other Benefits | Canada
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.10%	3.90%	3.40%