Summary of Significant Accounting Policies - Weighted Average Number of Shares Outstanding Used to Compute Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Accounting Policies [Abstract]
Net income	$ 7,930	$ 7,472
Weighted-average number of common shares outstanding
Basic weighted-average common shares outstanding (in shares)	11,610	11,434
Dilutive potential common shares (in shares)	245	321
Diluted weighted-average common shares outstanding (in shares)	11,855	11,755
Earnings per share
Basic (in dollars per share)	$ 0.68	$ 0.65
Diluted (in dollars per share)	$ 0.67	$ 0.64