Other Costs and Expenses - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Document Period End Date			Jun. 30, 2018
Business Acquisition, Transaction Costs	$ 9.4	$ 5.6	$ 15.3	$ 45.6
Centredale Site [Member]
Environmental Costs Recognized, Capitalized	$ 77.7		$ 77.7