Retirement and Other Employee Benefits - Fair Values of Plan Assets by Asset Category (Detail) - USD ($) $ in Millions		Jan. 01, 2016	Dec. 26, 2014	Dec. 27, 2013
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		$ 13.4	$ 14.1
Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		2.9	2.7
Bond securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		2.6	2.3
Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		4.7	5.1
Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		3.2	4.0
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		13.5	14.1
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		2.9	2.7
Quoted Prices in Active Markets for Identical Assets (Level 1) | Bond securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		2.7	2.3
Quoted Prices in Active Markets for Identical Assets (Level 1) | Value securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		4.7	5.1
Quoted Prices in Active Markets for Identical Assets (Level 1) | Growth securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		3.2	4.0
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 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
US Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	13.4	14.1	$ 14.2
United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		53.4	55.4
United Kingdom | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.3	0.1
United Kingdom | United Kingdom companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		22.1	23.1
United Kingdom | United States companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets			0.0
United Kingdom | Other international companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		20.1	20.5
United Kingdom | United Kingdom government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		4.6	5.0
United Kingdom | United Kingdom corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		6.3	6.7
United Kingdom | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		53.4	55.4
United Kingdom | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.3	0.1
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		22.1	23.1
United Kingdom | Quoted Prices in Active Markets for Identical Assets (Level 1) | United States companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets			0.0
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		20.1	20.5
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		4.6	5.0
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		6.3	6.7
United Kingdom | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
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		0.0	0.0
United Kingdom | Significant Observable Inputs (Level 2) | United States companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets			0.0
United Kingdom | Significant Observable Inputs (Level 2) | Other international companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
United Kingdom | Significant Observable Inputs (Level 2) | United Kingdom government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
United Kingdom | Significant Observable Inputs (Level 2) | United Kingdom corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		0.0	0.0
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) | 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) | United States companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets			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	0.0
United Kingdom | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	$ 53.4	$ 55.4	$ 54.9

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