Quarterly Financial Data (Unaudited) - Schedule of Quarterly Financial Data (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended
	Dec. 30, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017
Selling Delivery and Administrative Expenses [Member] | Out of Period Adjustment [Member] | CONA [Member]
Out-of-period adjustment to correct understated expense	$ 6.9
Other Expense [Member] | Non-service Cost Components of Net Periodic Benefit Cost [Member] | ASU 2017-07 [Member]
Net periodic benefit cost		$ 1.3	$ 1.3	$ 1.3	$ 1.3