Accounts receivable, net (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2013	Dec. 28, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts	$ (2,702)	$ (2,666)
Total accounts receivable, net	86,446	85,361
Billed accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	59,878	54,653
Unbilled accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 29,270	$ 33,374