Related Party Transactions - Summary of Awards Each Year (Detail) - Class B Common Stock - shares	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018
Schedule of Capitalization, Equity [Line Items]
Date of approval for award	Mar. 05, 2019	Mar. 06, 2018
Fiscal year of service covered by award	2018	2017
Shares settled in cash (in shares)	15,476	16,504
Increase in Class B Common Stock shares outstanding (in shares)	19,224	20,296
Total Class B Common Stock awarded (in shares)	34,700	36,800