Restricted Stock and Performance-Based Restricted Stock Activity Related to Equity Incentive Plans (Detail) - $ / shares		12 Months Ended
		Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Share-based Payment Arrangement [Abstract]
Restricted Stock, Nonvested Shares at beginning of period		190,379	194,604	276,220
Restricted Stock, Nonvested Shares granted		67,570	91,430	72,250
Restricted Stock, Nonvested Shares cancelled		(17,923)	(12,692)	(16,109)
Restricted Stock, Nonvested Shares vested		(68,956)	(82,963)	(137,757)
Restricted Stock, Nonvested Shares at end of period		171,070	190,379	194,604
Weighted Average Grant Date Fair Value at beginning of period	[1]	$ 213.57	$ 147.94	$ 97.48
Weighted Average Grant Date Fair Value, granted	[1]	275.06	271.33	205.21
Weighted Average Grant Date Fair Value, cancelled	[1]	230.60	178.06	115.71
Weighted Average Grant Date Fair Value, vested	[1]	175.84	128.57	80.55
Weighted Average Grant Date Fair Value at end of period	[1]	$ 251.29	$ 213.57	$ 147.94

[1] The weighted average grant date fair value for performance-based restricted shares granted was calculated based on the market price on the grant dates. Certain tranches will ultimately be valued when the performance condition is established for each tranche, which generally occurs in the fourth quarter of each fiscal year.