Postretirement Plans - Summary of Amounts Recognized in Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Dec. 30, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Accrued benefits	$ (5.2)	$ (4.7)
Retiree health care benefits	(36.0)	(36.7)
Net liability	(162.6)	(250.6)
U.S. Postretirement Health Care Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued benefits	(3.1)	(3.3)
Retiree health care benefits	(36.0)	(36.7)
Net liability	$ (39.1)	$ (40.0)