Employee Retirement Plans and Post-Retirement Medical Benefits - Additional Information (Detail) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2020	Dec. 31, 2022 USD ($) CompensationPlan	Dec. 25, 2021 USD ($)	Dec. 26, 2020 USD ($)	Dec. 28, 2019 USD ($)
Pension Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Unfunded projected pension benefits				$ 0
Retiree Medical Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Unfunded projected pension benefits		$ (757)	$ (1,040)
Non-Union Plans | Boston Beer 401 (k) Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Eligibility timing		eligible to participate in the Plan immediately upon employment
Voluntary contributions of annual compensation		60.00%
Employer matching contribution percentage		5.00%
Contributions Plan		$ 7,600	$ 7,400	6,400
Non-Union Plans | Boston Beer 401 (k) Plan | Company's match thereafter
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer matching contribution percentage	3.00%
Employer match percentage	100.00%
Non-Union Plans | Boston Beer 401 (k) Plan | Company's match for the first 3% of the eligible participants contribute
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer matching contribution percentage	2.00%
Employer match percentage	50.00%
Union Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of retirement plans | CompensationPlan		3
Union Plans | Company Sponsored Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Eligibility timing			open to all union employees who are covered by the Company’s collective bargaining agreement with Local Union 1199, or persons on leave from the Company who were employed by Local Union 1199, and in either case who had completed 12 consecutive months of employment with at least 750 hours worked.
Eligibility period			12 months
Time required for eligibility			750 hours
Expenses on termination of defined benefit plan				2,000
Pension contributions				$ 2,900	$ 300
Union Plans | Retiree Medical Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Eligibility period		20 years
Time required for eligibility		5 years
Benefit obligation, discount rate		5.22%	2.86%
Benefit obligation, rate of compensation increase		2.50%	2.50%
Percentage paid for coverage		100.00%
Union Plans | Retiree Medical Plan | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Voluntarily retirement age		57 years
Union Plans | Retiree Medical Plan | Local #20 member
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Time required for eligibility		7 years
Retiree Medical Plan, last years of employment		10 years
Voluntarily retirement age		65 years
Union Plans | Retiree Medical Plan | Local #20 member | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Eligibility period		20 years
Union Plans | Samuel Adams Cincinnati Brewery 401 (k) Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Eligibility timing		all members of Local 1 and Local 20 upon commencement of employment or, if later, attaining age 21.
Voluntary contributions of annual compensation		60.00%