Acquisitions - Allocation of Purchase Price to Fair Value of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Mar. 23, 2018	Dec. 30, 2017
Business Acquisition [Line Items]
Goodwill	$ 1,137.3		$ 1,104.7
Crystal Rock Acquisition [Member]
Business Acquisition [Line Items]
Cash		$ 1.6
Accounts receivable		6.5
Inventory		2.3
Prepaid expenses and other assets		1.2
Property, plant & equipment		9.4
Goodwill		16.7
Intangible assets		13.3
Other assets		0.8
Short-term borrowings		(4.1)
Current maturities of long-term debt		(1.6)
Accounts payable and accrued liabilities		(5.2)
Long-term debt		(10.4)
Deferred tax liabilities		(6.5)
Other long-term liabilities		(2.5)
Total		$ 21.5