Retirement and Other Employee Benefits - Fair Values of Plan Assets by Asset Category (Detail) - USD ($) $ in Millions	Dec. 29, 2017	Dec. 30, 2016	Jan. 01, 2016
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		$ 13.1
Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		1.8
Bond securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		3.6
Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		4.2
Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		3.5
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		13.1
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		1.8
Quoted Prices in Active Markets for Identical Assets (Level 1) | Bond securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		3.6
Quoted Prices in Active Markets for Identical Assets (Level 1) | Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		4.2
Quoted Prices in Active Markets for Identical Assets (Level 1) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		3.5
Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
Significant Observable Inputs (Level 2) | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
Significant Observable Inputs (Level 2) | Bond securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
Significant Observable Inputs (Level 2) | Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
Significant Observable Inputs (Level 2) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
Significant Unobservable Inputs (Level 3) | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
Significant Unobservable Inputs (Level 3) | Bond securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
Significant Unobservable Inputs (Level 3) | Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
Significant Unobservable Inputs (Level 3) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
United States | Pension plans
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	$ 13.9	13.1	$ 13.4
United States | Pension plans | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	5.7
United States | Pension plans | Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	3.8
United States | Pension plans | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	4.4
United States | Pension plans | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	13.9
United States | Pension plans | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	5.7
United States | Pension plans | Quoted Prices in Active Markets for Identical Assets (Level 1) | Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	3.8
United States | Pension plans | Quoted Prices in Active Markets for Identical Assets (Level 1) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	4.4
United States | Pension plans | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0
United States | Pension plans | Significant Observable Inputs (Level 2) | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0
United States | Pension plans | Significant Observable Inputs (Level 2) | Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0
United States | Pension plans | Significant Observable Inputs (Level 2) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0
United States | Pension plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0
United States | Pension plans | Significant Unobservable Inputs (Level 3) | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0
United States | Pension plans | Significant Unobservable Inputs (Level 3) | Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0
United States | Pension plans | Significant Unobservable Inputs (Level 3) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0
United Kingdom | Pension plans
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	61.3	50.5	$ 53.4
United Kingdom | Pension plans | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.2	0.4
United Kingdom | Pension plans | United Kingdom companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	5.5	4.8
United Kingdom | Pension plans | Diversified growth funds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	20.8	17.4
United Kingdom | Pension plans | Other international companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	18.5	17.1
United Kingdom | Pension plans | United Kingdom government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	7.1	4.4
United Kingdom | Pension plans | Liability-driven investments
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	9.2	6.4
United Kingdom | Pension plans | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.2	0.4
United Kingdom | Pension plans | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.2	0.4
United Kingdom | Pension plans | Quoted Prices in Active Markets for Identical Assets (Level 1) | United Kingdom companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets
United Kingdom | Pension plans | Quoted Prices in Active Markets for Identical Assets (Level 1) | Diversified growth funds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets
United Kingdom | Pension plans | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other international companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets
United Kingdom | Pension plans | Quoted Prices in Active Markets for Identical Assets (Level 1) | United Kingdom government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets
United Kingdom | Pension plans | Quoted Prices in Active Markets for Identical Assets (Level 1) | Liability-driven investments
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets
United Kingdom | Pension plans | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	61.1	50.1
United Kingdom | Pension plans | Significant Observable Inputs (Level 2) | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0	0.0
United Kingdom | Pension plans | Significant Observable Inputs (Level 2) | United Kingdom companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	5.5	4.8
United Kingdom | Pension plans | Significant Observable Inputs (Level 2) | Diversified growth funds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	20.8	17.4
United Kingdom | Pension plans | Significant Observable Inputs (Level 2) | Other international companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	18.5	17.1
United Kingdom | Pension plans | Significant Observable Inputs (Level 2) | United Kingdom government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	7.1	4.4
United Kingdom | Pension plans | Significant Observable Inputs (Level 2) | Liability-driven investments
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	9.2	6.4
United Kingdom | Pension plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0	0.0
United Kingdom | Pension plans | Significant Unobservable Inputs (Level 3) | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0	0.0
United Kingdom | Pension plans | Significant Unobservable Inputs (Level 3) | United Kingdom companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0	0.0
United Kingdom | Pension plans | Significant Unobservable Inputs (Level 3) | Diversified growth funds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0	0.0
United Kingdom | Pension plans | Significant Unobservable Inputs (Level 3) | Other international companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0	0.0
United Kingdom | Pension plans | Significant Unobservable Inputs (Level 3) | United Kingdom government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	0.0	0.0
United Kingdom | Pension plans | Significant Unobservable Inputs (Level 3) | Liability-driven investments
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	$ 0.0	$ 0.0