Acquisitions - Allocation of Purchase Price (Detail) - USD ($) $ in Millions	Mar. 30, 2019	Feb. 28, 2019	Dec. 29, 2018	Oct. 31, 2018	Mar. 23, 2018
Business Acquisition [Line Items]
Goodwill	$ 1,144.1	$ 20.1	$ 1,143.9
Mountain Valley Acquisition
Business Acquisition [Line Items]
Cash and cash equivalents		8.2		$ 8.2
Accounts receivable		4.2		4.2
Inventory		2.3		2.3
Prepaid expenses and other current assets		0.2		0.2
Property, plant and equipment		38.5		38.5
Intangible assets		25.8		25.8
Accounts payable and accrued liabilities		(19.3)		(19.3)
Total		80.0		80.4
Crystal Rock Acquisition
Business Acquisition [Line Items]
Cash and cash equivalents	1.6				$ 1.6
Accounts receivable	6.4				6.5
Inventory	2.2				2.3
Prepaid expenses and other current assets	2.2				1.2
Property, plant and equipment	8.9				9.4
Goodwill	14.2				16.7
Intangible assets	12.6				13.3
Other assets	0.1				0.8
Short-term borrowings	(4.1)				(4.1)
Current maturities of long-term debt	(1.6)				(1.6)
Accounts payable and accrued liabilities	(6.7)				(5.2)
Long-term debt	(10.4)				(10.4)
Deferred tax liabilities	(3.0)				(6.5)
Other long-term liabilities	(0.9)				(2.5)
Total	21.5				$ 21.5
Scenario, Adjustment | Mountain Valley Acquisition
Business Acquisition [Line Items]
Goodwill		(0.4)
Total		$ (0.4)
Scenario, Adjustment | Crystal Rock Acquisition
Business Acquisition [Line Items]
Cash and cash equivalents	0.0
Accounts receivable	(0.1)
Inventory	(0.1)
Prepaid expenses and other current assets	1.0
Property, plant and equipment	(0.5)
Goodwill	(2.5)
Intangible assets	(0.7)
Other assets	(0.7)
Short-term borrowings	0.0
Current maturities of long-term debt	0.0
Accounts payable and accrued liabilities	(1.5)
Long-term debt	0.0
Deferred tax liabilities	3.5
Other long-term liabilities	1.6
Total	$ 0.0
Mountain Valley Acquisition
Business Acquisition [Line Items]
Goodwill				$ 20.5