Accounts Receivable, Net (Detail) - USD ($) $ in Thousands	Mar. 30, 2018	Dec. 29, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for contract losses and doubtful accounts	$ (3,805)	$ (3,526)
Total accounts receivable, net	117,239	110,100
Billed accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable	76,121	78,139
Unbilled accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable	$ 44,923	$ 35,487