Equity-Based Compensation - Effect of Recording Equity-Based Compensation (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation	$ 858	$ 751	$ 2,186	$ 2,260
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation	47	213	411	610
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation	495	375	1,311	1,018
ESPP awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation	$ 316	$ 163	$ 464	$ 632