Commitments and Contingencies - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) Vendor	Dec. 30, 2017 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Contractual obligations	$ 193.6
Operating Leases
Commitments and Contingencies Disclosure [Line Items]
Contractual obligations	$ 14.3	$ 12.8
Lease expiration dates	2028
Equipment and machinery
Commitments and Contingencies Disclosure [Line Items]
Contractual obligations	$ 10.5
Minimum
Commitments and Contingencies Disclosure [Line Items]
Company's current brewing and packaging percentage	85.00%
Barley and Wheat
Commitments and Contingencies Disclosure [Line Items]
Number of suppliers | Vendor	2
Purchase commitments outstanding	$ 11.3
Hops
Commitments and Contingencies Disclosure [Line Items]
Purchase commitments	46.8
Hops, Barley and Wheat
Commitments and Contingencies Disclosure [Line Items]
Contractual obligations	58.1
Other Ingredients
Commitments and Contingencies Disclosure [Line Items]
Contractual obligations	22.2
Glass Bottles
Commitments and Contingencies Disclosure [Line Items]
Contractual obligations	10.5
Purchase commitments	10.5
Advertising Contracts
Commitments and Contingencies Disclosure [Line Items]
Contractual obligations	68.4
Other Commitments
Commitments and Contingencies Disclosure [Line Items]
Contractual obligations	$ 9.6