Option Activity and Changes (Detail)	3 Months Ended
	Mar. 30, 2019 $ / shares shares
Shares
Options outstanding at December 29, 2018 | shares	2,070,749
Options granted | shares	13,125
Options cancelled and forfeited | shares	(8,992)
Options exercised | shares	(72,122)
Options outstanding at March 30, 2019 | shares	2,002,760
Options exercisable at March 30, 2019 | shares	1,300,175
Weighted Average Exercise Price
Options outstanding at December 29, 2018 | $ / shares	$ 6.76
Options granted | $ / shares	6.08
Options cancelled and forfeited | $ / shares	7.43
Options exercised | $ / shares	4.22
Options outstanding at March 30, 2019 | $ / shares	6.84
Options exercisable at March 30, 2019 | $ / shares	$ 6.72