Accounts Receivable, Net - Additional Information (Detail) - USD ($)	6 Months Ended
	Jul. 03, 2020	Jun. 28, 2019	Jan. 03, 2020
Accounts Notes And Loans Receivable [Line Items]
Provision for contract losses and doubtful accounts	$ 2,817,000	$ 1,786,000
Accounts receivable, net current	109,341,000		$ 120,138,000
PG&E [Member]
Accounts Notes And Loans Receivable [Line Items]
Accounts receivable, net current	3,000,000.0
Economic Uncertainty of COVID-19 Pandemic [Member]
Accounts Notes And Loans Receivable [Line Items]
Provision for contract losses and doubtful accounts	$ 1,450,000