Retirement and Other Employee Benefits - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 28, 2018	Dec. 27, 2019	Dec. 28, 2018	Dec. 29, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net gains occurring during the year		$ 5.9	$ 5.1
Retirement benefits	$ 91.3	98.1	91.3
Foreign Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Retirement benefits	16.8	18.0	16.8
Pension plans | Foreign Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net gains occurring during the year		1.3	1.4
Pension plans | United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected contributions in next fiscal year		0.7
Plan amendment due to GMP equalization		0.0	0.0
Net gains occurring during the year		0.3	1.1
Net periodic pension costs		0.0	(0.1)	$ 0.0
Expected future benefit payments, thereafter		5.0
Pension plans | United States | Change in Assumptions for Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Increase (decrease) in benefit obligation		(0.2)
Pension plans | United Kingdom
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected contributions in next fiscal year		1.8
Payments to members electing transfer out of benefit plan		4.2
Payments for transfers to members electing out of benefit plan		3.8
Payments for enhancements to members electing out of benefit plan		0.4
Plan amendment due to GMP equalization		0.0	1.4
Net gains occurring during the year		(3.0)	5.7
Net periodic pension costs		(0.1)	(1.4)	(0.9)
Expected future benefit payments, thereafter		$ 12.4
Pension plans | United Kingdom | Diversified growth funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets target allocation percentage, equity securities		28.00%
Pension plans | United Kingdom | Emerging market equities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets target allocation percentage, equity securities		7.50%
Pension plans | United Kingdom | Liability-driven investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets target allocation percentage, equity securities		37.00%
Pension plans | United Kingdom | Global equities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets target allocation percentage, equity securities		7.50%
Pension plans | United Kingdom | Multi-asset credits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets target allocation percentage, equity securities		20.00%
Post-retirement plans | Foreign Plan | Former Executives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Retirement benefits	2.1	$ 2.3	2.1
Post-retirement plans | United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined contribution plan expense		1.3	1.1	1.2
Post-retirement plans | Central America
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan amendment due to GMP equalization		0.0	0.0
Net gains occurring during the year		6.6	(6.6)
Net periodic pension costs		10.2	10.7	10.8
Expected future benefit payments, thereafter		32.3
Post-retirement plans | Kenya
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accrued benefits	7.3	8.6	7.3
Net gains occurring during the year		(2.6)	(2.0)
Net periodic pension costs		1.3	1.2	1.2
Expected future benefit payments, next five years		5.0
Expected future benefit payments, thereafter		5.9
Supplemental unemployment benefits | Central America
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accrued benefits	4.2	3.7	4.2
Net gains occurring during the year		0.5	0.7
Net periodic pension costs		0.0	0.1	0.1
Expected future benefit payments, next five years		2.9
Expected future benefit payments, thereafter		$ 1.1
Minimum | Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan asset target allocation percentage		50.00%
Minimum | Fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan asset target allocation percentage		30.00%
Maximum | Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan asset target allocation percentage		70.00%
Maximum | Fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan asset target allocation percentage		50.00%
Operating income | Accounting Standards Update 2017-07
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Effect of new accounting principle	$ (3.3)			(4.3)
Other expense, net | Accounting Standards Update 2017-07
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Effect of new accounting principle			$ 3.3	$ 4.3