Option Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Jan. 03, 2020 USD ($) $ / shares shares	[1]
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of shares outstanding, Options Balance | shares	778,000
Number of shares outstanding, Options Granted | shares	50,000
Number of shares outstanding, Options forfeited and expired | shares	0
Exercise of stock options (in shares) | shares	(165,851)
Number of shares outstanding, Options Balance | shares	662,149
Number of shares outstanding, Exercisable | shares	450,649
Weighted-average exercise price, Options Balance | $ / shares	$ 20.80
Weighted-average exercise price, Options Granted | $ / shares	54.95
Weighted-average exercise price, Options forfeited and expired | $ / shares	0
Weighted-average exercise price, Options Exercised | $ / shares	9.41
Weighted-average exercise price, Options Balance | $ / shares	26.23
Weighted-average exercise price, Exercisable | $ / shares	$ 20.99
Weighted average remaining contractual term, Balance	5 years 10 months 6 days
Weighted average remaining contractual term, Exercisable	4 years 11 months 4 days
Aggregate intrinsic value, Balance | $	$ 29,290
Aggregate intrinsic value, Exercisable | $	$ 22,292

[1] Does not include restricted stock or employee stock purchase plans.