Accounts Receivable, Net (Detail) - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 29, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for contract losses and doubtful accounts	$ (3,644)	$ (3,526)
Total accounts receivable, net	116,532	110,100
Billed accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable	77,953	78,139
Unbilled accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable	$ 42,223	$ 35,487