Retirement and Other Employee Benefits - Reconciliation of Benefit Obligations, Plan Assets and Funded Status for Defined Benefit Pension Plans and Post-Retirement Plans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 27, 2019	Dec. 28, 2018	Dec. 29, 2017
Change in Plan Assets:
Beginning fair value	$ 11.9
Ending fair value		$ 11.9
Amounts recognized in Accumulated other comprehensive loss:
Net gains occurring during the year	5.9	5.1
Foreign Plan | Pension plans
Amounts recognized in Accumulated other comprehensive loss:
Net gains occurring during the year	1.3	1.4
United States | Pension plans
Change in Benefit Obligation:
Beginning benefit obligation	15.2	16.7
Service cost	0.0	0.0	$ 0.0
Interest cost	0.6	0.5	0.6
Actuarial (gain) loss	1.5	(0.7)
Benefits paid	(1.3)	(1.3)
Exchange rate changes	0.0	0.0
Settlement gain	0.0	0.0
Plan amendment	0.0	0.0
Ending benefit obligation	16.0	15.2	16.7
Change in Plan Assets:
Beginning fair value	11.9	13.9
Actual return on plan assets	2.2	(0.9)
Company contributions	0.2	0.2
Effect of settlements	0.0	0.0
Benefits paid	(1.3)	(1.3)
Exchange rate changes	0.0	0.0
Ending fair value	13.0	11.9	13.9
Amounts recognized in the Consolidated Balance Sheets:
Accounts payable and accrued expenses (current liability)	0.0	0.0
Retirement benefits liability (noncurrent liability)	3.0	3.2
Net amount recognized in the Consolidated Balance Sheets	3.0	3.2
Amounts recognized in Accumulated other comprehensive loss:
Net actuarial loss	(9.3)	(9.4)
Net amount recognized in accumulated other comprehensive loss	(9.3)	(9.4)	(8.7)
Net gains occurring during the year	0.3	1.1
United Kingdom | Pension plans
Change in Benefit Obligation:
Beginning benefit obligation	58.4	64.6
Service cost	0.0	0.0	0.0
Interest cost	1.4	1.5	1.5
Actuarial (gain) loss	3.6	(3.0)
Benefits paid	(1.9)	(2.3)
Exchange rate changes	1.8	(3.8)
Settlement gain	(4.4)	0.0
Plan amendment	0.0	1.4
Ending benefit obligation	58.9	58.4	64.6
Change in Plan Assets:
Beginning fair value	52.3	61.3
Actual return on plan assets	8.4	(5.0)
Company contributions	1.8	1.8
Effect of settlements	(4.4)	0.0
Benefits paid	(1.9)	(2.3)
Exchange rate changes	1.8	(3.5)
Ending fair value	58.0	52.3	61.3
Amounts recognized in the Consolidated Balance Sheets:
Accounts payable and accrued expenses (current liability)	0.0	0.0
Retirement benefits liability (noncurrent liability)	0.9	6.0
Net amount recognized in the Consolidated Balance Sheets	0.9	6.0
Amounts recognized in Accumulated other comprehensive loss:
Net actuarial loss	(4.6)	(7.7)
Net amount recognized in accumulated other comprehensive loss	(4.6)	(7.7)	(1.7)
Net gains occurring during the year	(3.0)	5.7
Central America | Post-retirement plans
Change in Benefit Obligation:
Beginning benefit obligation	61.2	67.1
Service cost	5.4	5.9	5.6
Interest cost	4.7	4.0	4.4
Actuarial (gain) loss	6.6	(6.6)
Benefits paid	(8.1)	(5.7)
Exchange rate changes	1.3	(3.5)
Settlement gain	0.0	0.0
Plan amendment	0.0	0.0
Ending benefit obligation	71.1	61.2	67.1
Change in Plan Assets:
Beginning fair value	0.0	0.0
Actual return on plan assets	0.0	0.0
Company contributions	8.1	5.7
Effect of settlements	0.0	0.0
Benefits paid	(8.1)	(5.7)
Exchange rate changes	0.0	0.0
Ending fair value	0.0	0.0	0.0
Amounts recognized in the Consolidated Balance Sheets:
Accounts payable and accrued expenses (current liability)	8.2	8.1
Retirement benefits liability (noncurrent liability)	62.9	53.1
Net amount recognized in the Consolidated Balance Sheets	71.1	61.2
Amounts recognized in Accumulated other comprehensive loss:
Net actuarial loss	(13.1)	(6.4)
Net amount recognized in accumulated other comprehensive loss	(13.1)	(6.4)	$ (14.2)
Net gains occurring during the year	$ 6.6	$ (6.6)