Retirement and Other Employee Benefits - Fair Values of Plan Assets by Asset Category (Detail) - USD ($) $ in Millions		Dec. 30, 2016	Jan. 01, 2016	Dec. 26, 2014
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		$ 13.1	$ 13.4
Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		1.8	2.9
Bond securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		3.6	2.6
Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		4.2	4.7
Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		3.5	3.2
Liability-driven investments
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		6.4
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		13.1	13.4
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	2.9
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	2.6
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	4.7
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	3.2
Quoted Prices in Active Markets for Identical Assets (Level 1) | Liability-driven investments
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets
Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
Significant Observable Inputs (Level 2) | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
Significant Observable Inputs (Level 2) | Bond securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
Significant Observable Inputs (Level 2) | Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
Significant Observable Inputs (Level 2) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
Significant Observable Inputs (Level 2) | Liability-driven investments
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		6.4
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
Significant Unobservable Inputs (Level 3) | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
Significant Unobservable Inputs (Level 3) | Bond securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
Significant Unobservable Inputs (Level 3) | Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
Significant Unobservable Inputs (Level 3) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
Significant Unobservable Inputs (Level 3) | Liability-driven investments
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
US Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	13.1	13.4	$ 14.1
United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		50.5	53.4
United Kingdom | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		17.4
United Kingdom | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.4	0.3
United Kingdom | United Kingdom companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		4.8	22.1
United Kingdom | Other international companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		17.1	20.1
United Kingdom | United Kingdom government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		4.4	4.6
United Kingdom | United Kingdom corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets			6.3
United Kingdom | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.4	0.3
United Kingdom | Quoted Prices in Active Markets for Identical Assets (Level 1) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets
United Kingdom | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.4	0.3
United Kingdom | 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 | 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 | 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 | Quoted Prices in Active Markets for Identical Assets (Level 1) | United Kingdom corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets
United Kingdom | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		50.1	53.1
United Kingdom | Significant Observable Inputs (Level 2) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		17.4
United Kingdom | Significant Observable Inputs (Level 2) | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
United Kingdom | Significant Observable Inputs (Level 2) | United Kingdom companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		4.8	22.1
United Kingdom | Significant Observable Inputs (Level 2) | Other international companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		17.1	20.1
United Kingdom | Significant Observable Inputs (Level 2) | United Kingdom government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		4.4	4.6
United Kingdom | Significant Observable Inputs (Level 2) | United Kingdom corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets			6.3
United Kingdom | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
United Kingdom | Significant Unobservable Inputs (Level 3) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0
United Kingdom | Significant Unobservable Inputs (Level 3) | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
United Kingdom | 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 | 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 | 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 | Significant Unobservable Inputs (Level 3) | United Kingdom corporate bonds
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	[1]	$ 50.5	$ 53.4	$ 55.4

[1] The accumulated benefit obligation is the same as the projected benefit obligation.