Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts
Balance, beginning of period	$ 957	$ 982	$ 1,656
Provision	315	39	(570)
Charge-offs	(111)	(64)	(151)
Acquisitions and other	98		47
Balance, end of period	1,259	957	982
Allowance for Customer Credits [Member]
Valuation and Qualifying Accounts
Balance, beginning of period	105,950	90,596	95,537
Provision	308,783	274,243	203,677
Charge-offs	(258,982)	(258,889)	(208,665)
Acquisitions and other			47
Balance, end of period	$ 155,751	$ 105,950	$ 90,596