Receivables, net (Details) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2014	Dec. 28, 2013
Current and long-term receivables balances
Accounts receivable	$ 77,088	$ 76,057
Unbilled accounts receivable	24,836	31,567
Long-term receivables	5,611	3,672
Total receivables	107,535	111,296
Less allowance for doubtful accounts	0	0
Total receivables, net	$ 107,535	$ 111,296