Retirement and Other Employee Benefits - Assumptions Used in the Calculation of Benefit Obligations and Net Periodic Pension Costs of U.S. and U.K. Defined Benefit Pension Plans and Central American Plans (Detail)	12 Months Ended
	Dec. 27, 2019	Dec. 28, 2018	Dec. 29, 2017
Pension plans | United States
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rate	3.00%	4.10%	3.45%
Rate of increase in compensation levels	0.00%	0.00%	0.00%
Weighted average discount rate	4.10%	3.45%	3.85%
Rate of increase in compensation levels	0.00%	0.00%	0.00%
Expected long-term rate of return on assets	7.50%	7.50%	7.50%
Pension plans | United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rate	2.00%	2.80%	2.45%
Rate of increase in compensation levels	0.00%	0.00%	2.40%
Weighted average discount rate	2.80%	2.45%	2.60%
Rate of increase in compensation levels	0.00%	0.00%	2.50%
Expected long-term rate of return on assets	4.22%	4.22%	4.50%
Post-retirement plans | Central America
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rate	6.27%	8.06%	6.50%
Rate of increase in compensation levels	4.71%	4.75%	4.75%
Weighted average discount rate	8.12%	6.51%	7.10%
Rate of increase in compensation levels	4.71%	4.75%	4.75%
Expected long-term rate of return on assets	0.00%	0.00%	0.00%