Net Income per Share - Additional Information (Detail)	3 Months Ended										12 Months Ended
	Dec. 30, 2017 shares $ / shares		Sep. 30, 2017 $ / shares	Jul. 01, 2017 $ / shares	Apr. 01, 2017 $ / shares	Dec. 31, 2016 $ / shares	[2]	Sep. 24, 2016 $ / shares	Jun. 25, 2016 $ / shares	Mar. 26, 2016 $ / shares	Dec. 30, 2017 shares $ / shares	Dec. 31, 2016 $ / shares shares	Dec. 26, 2015 $ / shares shares
Earnings Per Share Note [Line Items]
Net income per common share - basic | $ / shares	$ 2.60	[1]	$ 2.82	$ 2.38	$ 0.46	$ 1.77		$ 2.53	$ 2.11	$ 0.55	$ 8.18	$ 6.93	$ 7.46
Conversion ratio for Class B to Class A shares	1										1
Stock options cancelled during the period											12,208
Common Class A
Earnings Per Share Note [Line Items]
Net income per common share - basic | $ / shares											$ 8.18	$ 6.93	$ 7.46
Antidilutive securities excluded from computation of earnings per share											785,000	712,000	16,000
Common Class A | Performance-Based Awards
Earnings Per Share Note [Line Items]
Stock options cancelled during the period											12,000
Common Class A | Performance-Based Awards
Earnings Per Share Note [Line Items]
Number of shares not included because the performance criteria was not expected to be met											36,000	35,000	15,000

[1] During the fourth quarter of 2017, the Company recorded a $20.3 million tax benefit due to the Tax Cuts and Jobs Act of 2017.

[2] During the fourth quarter of 2016, the Company recorded a $3.6 million decrease in stock-based compensation expense related to the planned retirement of the Company's Chief Executive Officer in 2018.