Capital Transactions - Summary of the Awards Each Year (Detail) - Class B Common Stock [Member] - shares	3 Months Ended
	Mar. 31, 2019	Apr. 01, 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 to satisfy tax withholding obligations	15,476	16,504
Increase in Class B Common Stock shares outstanding	19,224	20,296
Total Class B Common Stock awarded	34,700	36,800